Knowledge and Perceptions of a Gluten-Free Diet: a Mixed-Methods Approach

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Knowledge and Perceptions of a Gluten-Free Diet: A Mixed-Methods Approach

A thesis presented to

the faculty of

the College of Health Sciences and Professions of Ohio University

In partial fulfillment

of the requirements for the degree

Master of Science

Hannah E. Johnson

August 2017

This thesis titled

Knowledge and Perceptions of a Gluten-Free Diet: A Mixed-Methods Approach

HANNAH E. JOHNSON

has been approved for

the School of Applied Health Sciences and Wellness

and the College of Health Sciences and Professions by

Robert G. Brannan

Associate Professor of Food and Nutrition Sciences

Randy Leite

Dean, College of Health Sciences and Professions 3

Abstract

JOHNSON, HANNAH E., M.S., August 2017, Food and Nutrition Sciences

Knowledge and Perceptions of a Gluten-Free Diet: A Mixed-Methods Approach

Director of Thesis: Robert G. Brannan

The practice of gluten-free diets is on the rise, yet many people are still unaware of what gluten is and how it functions in food. It is important that food and nutrition professionals are knowledgeable on this topic due to the prevalence of gluten-related disorders and the popularity of gluten-free as a fad diet. The purpose of this research was to use a mixed methods approach using qualitative and quantitative methods to obtain and evaluate knowledge and perceptions of a gluten-free diet from future and current food and nutrition professionals. In the first phase of the research, a laboratory questionnaire was administered to assess students enrolled in the Food Science course on their knowledge of gluten. Concurrently, focus groups on the topic of gluten-free, consisting of former Food Science students, faculty, and/or other nutrition professionals were conducted. Thematic analysis was used to determine key concepts generated from the focus groups, and to foster the formation of a second questionnaire. The questionnaire was distributed to Registered Dietitians (RDs) to assess their knowledge and attitudes towards the gluten-free diet. A representative sample obtained from the Commission on

Dietetic Registration of 516 RDs across the United States completed the questionnaire on gluten and a gluten-free diet. Over 18% of respondents incorrectly identified gluten as a carbohydrate. Additionally, less than 80% of RDs correctly identified the presence or absence of gluten in semolina, spelt, kamut, and buckwheat. Regarding perceptions of a 4 gluten-free diet, participants reported that the public is not aware of what gluten is, a gluten-free diet is not appropriate for the general public or for weight loss, and the gluten- free diet is a fad when used outside of celiac disease and nonceliac gluten sensitivity.

Results of this research have determined that there is a need for further education about sources of gluten, labeling, and gluten-related disorders among future and current

Registered Dietitians. 5

Preface

Chapters 3 and 4 contained within the thesis document serve as prepublication manuscripts. These manuscripts have been formatted to meet the guidelines set forth by

Thesis and Dissertation Services at Ohio University. The style adhered to the APA

Publication Manual; otherwise the abstract style and the content of headings conformed to the Journal of the Academy of Nutrition and Dietetics and the Journal of Food Science

Education in chapters 3 and 4, respectively.

Dedication

I would like to dedicate this to my family and friends who supported me through this

endeavor.

Acknowledgments

I would like to thank everyone that helped in the completion of this research. To

Dr. Robert Brannan, thank you for all of your hard work and dedication for this research.

Your insight and guidance allowed me to completed research that I am truly proud of.

Thank you to Dr. Elizabeth Beverly and Ms. Deborah Murray for being a part of my thesis committee. Your feedback has been incredibly helpful throughout the past two years. Dr. Elizabeth Beverly, your experience in qualitative research was exceptionally invaluable when working on my focus groups and questionnaires. Deborah Murray, your experience as a Registered Dietitian was instrumental in determining how to assess a large sample of Registered Dietitians.

Table of Contents

Page

Abstract ...... 3

Dedication ...... 6

Acknowledgments ...... 7

List of Tables ...... 11

List of Figures ...... 13

Chapter 1: Introduction ...... 14

Statement of the Problem ...... 15

Objectives ...... 16

Research Questions ...... 16

Significance ...... 16

Limitations and Delimitations ...... 17

Chapter 2: Literature Review ...... 18

Cereals ...... 18

Gluten ...... 18

Function of gluten...... 21

Gluten-free products...... 23

Labeling...... 27

Gluten-Related Disorders ...... 29

Celiac disease...... 29

Nonceliac gluten sensitivity...... 35 9

Wheat allergy...... 37

Gluten-Free Diet ...... 40

Chapter 3: Knowledge and Perceptions of a Gluten-Free Diet: A Mixed Methods

Approach ...... 44

Abstract ...... 44

Introduction ...... 45

Materials and Methods ...... 47

Focus groups...... 47

Questionnaire...... 48

Results and Discussion ...... 50

Focus groups...... 50

Questionnaire...... 55

Relevance to Ohio...... 68

Conclusions ...... 68

References ...... 70

Chapter 4: Does a Hands-On Laboratory on the Topic of Gluten-Free Baking Increase

Knowledge of Gluten in Foods? ...... 83

Abstract ...... 83

Introduction ...... 84

Materials and Methods ...... 86

Questionnaire...... 86

Data analysis...... 88 10

Results and Discussion ...... 88

Demographics...... 89

Laboratory...... 89

Conclusions ...... 93

References ...... 94

Chapter 5: Discussion ...... 103

References ...... 105

Appendix A: Literature on Gluten-Free Products ...... 127

Appendix B: Focus Group Signed Consent Form ...... 138

Appendix C: Focus Group Outline ...... 140

Appendix D: RD Questionnaire ...... 141

Appendix E: RD Consent Form ...... 152

Appendix F: Supplemental Material to be Submitted to the Journal of the Academy of

Nutrition and Dietetics ...... 154

Appendix F: Pre- and Post-Laboratory Questionnaire ...... 176

Appendix G: Pre- and Post-Laboratory Consent Form ...... 186

Appendix H: 2016 Gluten-Free Laboratory Activity ...... 188

Appendix I: 2017 Gluten-Free Laboratory Activity ...... 193 11

List of Tables

Page

Table 1: Categorized Summary of Results From Focus Groups on the Topic of Gluten-

Free ...... 76

Table 2: Statements Rated on a 5-Point Hedonic Scale, Included in Gluten-Free

Questionnaire ...... 77

Table 3: Demographic Characteristics of Registered Dietitians Responding to a Gluten-

Free Questionnaire (n = 508) ...... 78

Table 4: Number of Registered Correctly Identifying Gluten-Containing and Gluten-Free

Foods (n = 508) ...... 79

Table 5: Populations that Should Follow a Gluten-Free Diet as Reported by Registered

Dietitians (n = 508) ...... 80

Table 6: Definition of Celiac Disease as Reported by Registered Dietitians (n = 508) ... 80

Table 7: Appropriate Diagnostic Method for Celiac Disease as Reported by Registered

Dietitians (n = 508) ...... 81

Table 8: Percent of American Population Diagnosed with Celiac Disease as Reported by

Registered Dietitians (n = 508) ...... 81

Table 9: Recipe Variations ...... 97

Table 10: Demographics of Respondents ...... 98

Table 11: Literature on Gluten-Free Products ...... 127

Table 12: Percent of American Population Diagnosed with Celiac Disease as Reported

by Registered Dietitians (n = 508) ...... 154 12

Table 13: Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as

Reported by Registered Dietitians, Based on Gender (n = 508) ...... 156

Table 14: Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as

Reported by Registered Dietitians, Based on Age Groups (n = 508) ...... 158

Table 15: Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as

Reported by Registered Dietitians, Based on Hispanic or Latino (n = 448) ...... 160

Table 16: Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as

Reported by Registered Dietitians, Based on Race (n = 508) ...... 162

Table 17: Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as

Reported by Registered Dietitians, Based on Region (n = 508) ...... 165

Table 18: Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as

Reported by Registered Dietitians, Based on Level of Education (n = 508) ...... 167

Table 19: Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as

Reported by Registered Dietitians, Based on Number of Years as a Registered

Dietitian (n = 508) ...... 169

Table 20: Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as

Reported by Registered Dietitians, Based on if Area of Practice Includes Celiac

Disease (n = 508) ...... 172

Table 21: Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as

Reported by Registered Dietitians, Based on Diagnosis of Gluten-Related Disorder

(Celiac Disease, Non-Celiac Gluten-Sensitivity, or Wheat Allergy) (n = 508) ...... 174

List of Figures

Page

Figure 1: Mean responses for hedonic questions on a gluten-free questionnaire from

Registered Dietitians (n = 508)...... 82

Figure 2: 2016 Correct responses for gluten-containing products...... 99

Figure 3: 2016 Correct responses for gluten-free products...... 100

Figure 4: 2017 Correct responses for gluten-containing products...... 101

Figure 5: 2017 Correct responses for gluten-free products...... 102 14

Chapter 1: Introduction

Gluten is a protein located in wheat’s endosperm; however, due to the comparable properties observed in rye and barley, it is often stated that gluten is located in wheat, rye, and barley (Ryan, 2015; Veloso, Dias, Rodrigues, & Peres, 2016). Gluten is comprised of two storage proteins, referred to as a prolamin and glutelin (Gessendorfer, Koehler, &

Wieser, 2009). In food science, gluten refers to the product that is formed when flour is mixed with water and agitated (Day, Augustin, Batey, & Wrigley, 2006). Gluten formation provides a number of desirable qualities in food, such as viscoelasticity and air pocket formation.

There is an increasing demand for gluten-free products, as evidenced by a rise in both the retail sales and consumption of gluten-free products in recent years (Roberts,

2016). A recent survey reported that of the population consuming gluten-free products,

25% are diagnosed with celiac disease, an autoimmune condition characterized by an immune response following the consumption of gluten, for which the only treatment is abstinence from gluten (Green, Lebwohl, & Greywoode, 2015). The remaining 75% of the population consuming gluten-free products does so for reasons other than a diagnosis of celiac disease or gluten sensitivity (Roberts, 2016). More broadly, data collected between 2009-2012 from the National Health and Nutrition Examination Surveys

(NHANES) found that 1.69% of the population above 6 years of age without celiac disease reported follow a gluten-free diet (Kim et al., 2016). Research suggests that an increase in public popularity of gluten-free diets probably is linked at some level to celebrity testimonials of the diet’s supposed health benefits, especially weight loss 15

(Gaesser & Angadi, 2012). However, there is no scientific evidence to prove that a gluten-free diet will result in weight loss among those without celiac disease. Individuals may in fact gain weight on a gluten-free diet due to the nutritional inadequacy of many gluten-free products.

For individuals with a medical condition that requires adherence to a gluten-free diet, it is important to know what ingredients contain gluten. Often this can be more complicated than looking for wheat, rye, or barley on an ingredient list. Items such as malt, durum, kamut, semolina, spelt and triticale contain gluten (Case, 2005). Due to this complication, many people on gluten-free diets unintentionally consume gluten

(Silvester, Weiten, Graff, Walker, & Duerksen, 2016). In 2013, the U.S. Food and Drug

Administration (FDA) released a set of guidelines for labeling products as gluten-free

(FDA, 2013). Food must contain less than 20 parts per million (ppm), or 20 mg/kg, of gluten for a manufacturers to use the phrase “gluten-free,” “free of gluten,” “without gluten,” or “no gluten” on the product label.

Registered Dietitians (RDs) must be equipped with sufficient knowledge of a gluten-free diet in order to provide optimal care to patients with celiac disease and nonceliac gluten sensitivity (Case, 2005; See, Kaukinen, Makharia, Gibson, & Murray,

2015). Patients need to receive education for topics including, but not limited to, sources of gluten in the diet, reading a nutrition facts label, eating out, and cross-contact.

Statement of the Problem

The practice of gluten-free diets is on the rise, yet many people are still unaware of what gluten is and how it functions in food. It is important that food and nutrition 16 professionals are knowledgeable about this topic due to the prevalence of gluten-related disorders and popularity of gluten-free as a fad diet. Currently, there is no existing research exploring the knowledge about gluten and the gluten-free diet of RDs to the best of the researcher’s knowledge.

Objectives

The purpose of this research was to employ a mixed-methods approach using qualitative and quantitative methods to obtain and evaluate knowledge and perceptions of gluten and a gluten-free diet from current and future nutrition professionals.

Research Questions

1. What is the current understanding and perception of gluten and a gluten-

free diet in nutrition students and faculty at Ohio University?

2. How effective is a hands-on laboratory on the topic of gluten-free baking

on students’ ability to identify gluten in common food ingredients?

3. What is the current knowledge and attitudes of gluten and a gluten-free

diet in RDs?

Significance

This research is the first to establish the current knowledge and perceptions of gluten and a gluten-free diet in nutrition students and RDs. The results of this research demonstrate a need for further education of gluten and the gluten-free diet in the field.

Additionally, this research provides information for the improvement of current educational materials. 17

Limitations and Delimitations

The focus group participants were limited to undergraduate Applied Nutrition students in the Dietetics concentration, graduate students majoring in Food and Nutrition

Sciences, and nutrition faculty members at Ohio University.

A convenience sample of future dietetics professionals in the form of students in

Ohio University’s NUTR 2220 class were sampled; therefore, this sample may not be representative of the population and the ability to generalize findings beyond the actual sample may be limited.

The questionnaire was sent only to a sample of RDs. The same questionnaire was not sent to a large group of nutrition students. Therefore, information regarding the knowledge and perceptions of gluten and a gluten-free diet in a generalizable sample of future nutrition professionals was not obtained.

Chapter 2: Literature Review

Cereals

Cereals are a major component of total dietary calorie intake, providing approximately 50% of total calories consumed worldwide (Wolrd Health Organization,

2003). The most common cereals include wheat, rye, barley, maize, oats, millet, and rice

(Belitz, Grosch, & Schieberle, 2009). Cereals are grasses within the Poaceae family that contain a fruit, referred to as a caryopsis. The three constituents of cereals are the endosperm, germ, and bran. The endosperm is primarily starch-based and contains most of the nutrients found within the grain. The germ encompasses the greatest concentration of lipids, compared to amounts found in the endosperm and bran. The bran is the outermost layer of the grain.

Cereal proteins are categorized into four groups, known as Osborne fractions; these groups are albumins, globulins, prolamins, and glutelins (Belitz et al., 2009;

Gessendorfer et al., 2009). Two of the Osborne fractions, prolamins and glutelins, form the gluten complex. Prolamins and glutelins are storage proteins, meaning that amino acids are stored within the protein (Wrigley, Békés, & Bushuk, 2006). Relative concentrations of Osborne fractions vary for each grain. Wheat contains 33% prolamins and 46% glutelins; rye contains 21% prolamins and 25% glutelins; and barley contains

25% prolamins and 55% glutelins.

Gluten

Gluten is a protein located in wheat’s endosperm; however, due to the comparable properties observed in rye and barley, it is often stated that gluten is located in wheat, rye, 19 and barley (Ryan, 2015; Veloso et al., 2016). Wheat, barley, and rye are all cereal grains belonging to the tribus Triticeae (Belitz et al., 2009). Within Triticeae, the three gluten- containing grains are divided into their genus. Triticum, Secale, and Hordeum are the respective genera for wheat, rye, and barley.

Prolamins are alcohol-soluble proteins with a monomeric structure, containing intramolecular disulphide bonds (Rallabhandi, Sharma, Pereira, & Williams, 2015). The prolamins in wheat, rye, and barley respectively are gliadin, secalin, and hordein

(Sharma, Pereira, & Williams, 2015). Proline and glutamine are highly abundant in prolamins.

Gliadins are divided into four distinct categories based on structural differences;

ω5-, ω1,2-, α/β-, and γ- (Wieser, 2007). Typically, α/β- and γ-gliadins represent a larger portion than ω-gliadins, in terms of total gliadin content. Although gliadins contain multiple amino acids, proline and glutamine account for over half of the composition in each of the four gliadins. The remaining fraction is predominantly comprised of phenylalanine, tyrosine, glycine, and cysteine. Despite cysteine comprising a very small portion of gluten’s structure, it is responsible for crucial intrachain and interchain disulphide bonds. Gliadins possess intrachain disulphide bonds in the C-terminal domain.

α/β-gliadins have six cysteines, creating three intrachain disulphide bonds. γ-gliadins have eight cysteines, forming four intrachain disulphide bonds. ω-gliadins do not contain cysteine and therefore do not have disulphide bonds (Belitz et al., 2009).

Glutelins are soluble in both acids and bases; they have a multimeric structure containing intra- and intermolecular disulphide bonds (Rallabhandi et al., 2015). Glutenin 20 refers to the glutelin fragment in wheat. The additional glutelins are identified as rye glutelin and barley glutelin. Similarly to prolamins, glutelins contain large concentrations of proline and glutamine.

Glutenins are classified into three types based on their varying molecular weight; low molecular weight glutenin subunits (LMW-GS), x-high molecular weight glutenin subunits (x-HMW-GS), and y-HMW-GS (Wieser, 2007). Both intrachain and interchain disulphide bonds are present in glutenins. LMW-GS have a molecular weight between

30,000 and 45,000 (Delcour et al., 2012). The molecular weights of y-HMW-GS are

67,000 to 74,000, while x-HMW-GS are 83,000 to 88,000.

The presence of gluten in oats has been a frequent topic of debate among researchers (Dessì, Noce, Vergovich, Noce, & Daniele, 2013). However, studies have shown that the properties found in oats differ from those in wheat, barley, and rye. The prolamin portion of oats, avenin, has notable differences from the prolamins of wheat, rye, and barley (Comino, Moreno, & Sousa, 2015). Much of the research compares oats to wheat, rather than to rye or barley.

Avenin, the prolamin present in oats, makes up only 14% of the total protein content of oats, whereas prolamins constitute 21%, 25%, and 33% of the protein content in rye, barley, and wheat (Belitz et al., 2009). Further, although avenin does contain proline and glutamine, the relative proportion of these amino acids, particularly proline, differs from that present in gliadin, secalin, and hordein. The proline concentration of avenin is only 10%. In contrast, the proline concentration in the other prolamins is: gliadin, 17%; secalin, 18%; and hordein, 23%. Additionally, avenin differs structurally 21 from wheat prolamin. The disulphide bond that connects two cysteines occurs at a different position in avenin versus gliadin.

Oat glutelin accounts for 54% of total protein content, while glutelins comprise

25%, 46%, and 55% in rye, wheat, and barley, respectively (Belitz et al., 2009). Proline concentrations are also lower in oat glutelin versus wheat, barley, and rye glutelins. Oat glutelins contain 6% proline, while wheat glutelin has 12%, barley has 14%, and rye has

9%.

Function of gluten. Because most of the research on gluten’s functionality in food is specific to wheat, rather than barley or rye, the information provided in this portion of the literature review will refer to wheat gluten, unless otherwise stated. In food science, gluten refers to the product that is formed when flour is mixed with water and agitated (Day et al., 2006). Gluten formation provides a number of desirable qualities in food, such as viscoelasticity and air pocket formation. Viscoelasticity is a crucial property achieved with gluten formation. Viscoelasticity is the ability of dough to stretch, while still maintaining its shape (Shewry, Halford, Belton, & Tatham, 2002). The creation of air pockets is a key characteristic resulting from gluten development (Wieser, 2007). Air pockets allow products such as baked goods to sustain a porous, yet stable structure

(Delcour et al., 2012).

Wheat varieties differ based on hardness, or relative protein concentration

(Delcour et al., 2012). Durum wheat is the hardest variety, with 9-18% protein. Soft wheat varieties contain 8-11% protein. Hard wheat is ideal for bread and pasta production, while soft wheat is optimal for cookies and cakes. 22

During bread making, flour and water are combined until dough is formed

(Delcour et al., 2012). Approximately 60 g of water is required for every 100 g of flour.

Throughout this process, agitation causes the gluten in the flour to become hydrated. A gluten complex forms around the starch granules, creating the desired viscoelastic dough.

Glutenin chains contain hydrogen bonds, both as intrachain and interchain bonds, which are responsible for the dough elasticity. Gliadin provides viscosity to the dough.

Fermentation produces carbon dioxide, which is retained within the dough’s gluten complex. After fermentation, alterations in the dough’s structure continue during baking.

Increases in temperature leads to starch gelatinization, in which moisture is removed from the gluten proteins. The lack of moisture creates rigid air cell walls. The rigidity produces a stable structure enclosing numerous air pockets. The final product is able to maintain its structure without becoming too dense.

Pasta production utilizes gluten through an entirely different method than bread making (Delcour et al., 2012). Semolina, a derivative of durum wheat, is used to initiate pasta production. A small amount of water is combined with the semolina to create dough with moisture content of approximately 31%. Following this step, the dough is then formed into the desired shape. Subsequently, the pasta is exposed to elevated temperatures and dried. The high temperature causes polymerization of glutenin and gliadin. As a result, the pasta becomes dense with a continuous protein network.

Edible films are coatings that are safe for consumption and protect food from moisture and oxygen (Bourtoom, 2008). Gluten has been studied for its value as an edible film (Mojumdar, Moresoli, Simon, & Legge, 2011). Gluten films provide an effective 23 barrier to oxygen. Film production includes a drying phase, in which solvents are removed. This process creates new hydrogen and disulphide bonds within the gluten complex, producing a functional oxygen barrier. Due to this functionality, gluten films are appropriate for food vulnerable to oxidation.

Gluten-free products. There has been a rise in both the retail sales and consumption of gluten-free products in recent years (Roberts, 2016). The reported consumption of gluten-free foods increased from 24% in 2013, to 32% in 2016. Retail sales of gluten-free products increased from approximately $5 million in 2013, to $13.6 million in 2016. Examples of types of gluten-free products on the market that replace their gluten-containing counterparts include cereal, granola bars, chips, soup, cookies, oatmeal, and breadcrumbs.

Roberts (2016) reported that of the population consuming gluten-free products,

25% are diagnosed with celiac disease, an autoimmune condition characterized by an immune response following the consumption of gluten, for which the only treatment is abstinence from gluten (Green et al., 2015). The remaining 75% of people eating gluten- free products do so for reasons other than a diagnosis of celiac disease or gluten sensitivity (Roberts, 2016). Nonceliac respondents frequently report eating gluten-free products for a variety of reasons. A few notable motives for the consumption of gluten- free products include the notion that gluten-free is better for overall health, provides more energy, and helps with weight loss.

Gluten-free products often have noticeable quality differences compared to their gluten-containing counterparts (Zannini, Jones, Renzetti, & Arendt, 2012). A common 24 thread in most of the research on gluten-free products is that it is difficult to achieve comparable properties when gluten-free ingredients are used as a substitute in a traditionally gluten-containing food. Gluten-free products can often be crumbly and lack the desired structural stability. A representative list of research on the development of gluten-free products is shown in Appendix A, with most of the research focused on cookies, cakes, bread, muffins, and pasta. Overall, it is possible to develop gluten-free products that are accepted by the consumer; however, a gluten-containing control product is typically preferred.

There have been several studies dealing with optimizing quality in gluten-free cookies. In a study comparing the effects of wheat flour versus several gluten-free flours in sugar-snap cookies, many quality deficits were evident in the gluten-free products

(Mancebo, Picón, & Gómez, 2015). Buckwheat, amaranth, and maize flour cookies were significantly harder than the wheat cookie, which is typically an undesirable characteristic in cookies. Color differences were apparent among the varieties of cookies; this feature can make a product unappealing to customers.

Rice-based gluten-free muffins were analyzed for five textural properties; hardness, springiness, cohesiveness, chewiness, and resilience (Matos, Sanz, & Rosell,

2014). Soy protein isolate muffins and pea protein isolate muffins were statistically similar to the control no-protein muffins in all attributes. Muffins made with vital wheat gluten, egg white protein, or casein were significantly more springy and cohesive. The egg white protein muffins and casein muffins were chewier and more resilient than the 25 control. The casein muffins were the only variation that was significantly harder than the control.

Gluten-free bread is one of the most-researched products in the field of gluten- free product optimization. A variety of factors including taste, texture, appearance, and staling have been investigated for potential improvement in gluten-free bread. A study examining the effects of legume flour as a replacement for soya protein found that there were no significant differences in the consumer acceptability of bread formulated with soya flour, chickpea flour, pea isolate, or carob germ flour (Miñarro, Albanell, Aguilar,

Guamis, & Capellas, 2012).

Quinoa flour has been studied as a partial replacement for buckwheat in gluten- free bread (Turkut, Cakmak, Kumcuoglu, & Tavman, 2016). Increasing quinoa flour content up to 25% resulted in improved properties such as increased viscosity, and unchanged water activity and bake loss. In the sensory evaluation, the 25% quinoa flour bread demonstrated significantly improved overall liking compared to the control bread with no added quinoa flour.

Sourdough has been investigated for its potential use in improving shelf life and textural characteristics of gluten-free bread (O’Shea, Arendt, & Gallagher, 2014).

Sourdough is produced through a combination of flour, water, yeast, and lactic acid bacteria (LAB). Lactobacillus plantarum FST 1.7, a specific strain of LAB, demonstrated antifungal properties when incorporated in gluten-free sourdough (Moore, Dal Bello, &

Arendt, 2008). In addition, bread utilizing lactobacillus plantarum FST 1.7 was significantly softer after 5 days, compared to the nonacidified control bread and the 26 chemically acidified bread. However, despite these promising results, there is still much more research to be done on the appearance, taste, and textural properties of gluten-free sourdough bread.

In addition to the possible use of sourdough in the enhancement of sensory qualities in gluten-free product, wheat sourdough has been researched for its safety in the celiac disease population (Greco et al., 2011). It has been theorized that the fermentation that occurs in sourdough production is capable of breaking down the existing gluten.

Unfortunately, the current research has many limitations and does not demonstrate adequate results to recommend wheat sourdough consumption on a gluten-free diet.

Gluten-free cakes are difficult to formulate, due to their light and porous structure.

Xanthan gum is capable of improving rheological characteristics of baked goods, and therefore is frequently used in gluten-free baking (Preichardt, Vendruscolo, Gularte, &

Moreira, 2011). Gluten-free cakes made with 0.3% (F2) and 0.4% (F3) xanthan gum exhibited specific volume statistically similar to cakes made with wheat flour. The cakes underwent sensory evaluation based on a nine-point hedonic scale. F2 received a mean score of 7.7 out of 9, while F3 had a mean score of 7.1 out of 9. These scores indicate that the addition of 0.3% and 0.4% xanthan gum in gluten-free cake is acceptable by sensory evaluation.

Gluten-free pasta is one of the most problematic gluten-free products to develop with properties that are comparable to traditional gluten-containing pasta (Marti &

Pagani, 2013). Gluten-free pasta often contains at least one starch-based ingredient and some form of gums and/or emulsifiers. A study exploring the impact of legume flour 27 supplementation in rice pasta showed promising results (Bouasla, Wójtowicz, & Zidoune,

2017). Rice pasta enriched with 10-30 g/100 g of yellow pea, chickpea, and/or lentil flour had statistically unchanged overall sensory acceptability compared to the control rice pasta.

Labeling. In 2013, the U.S. Food and Drug Administration (FDA) released a set of guidelines for labeling products as gluten-free (FDA, 2013). Food must contain less than 20 parts per million (ppm), or 20 mg/kg, of gluten for a manufacturers to use the phrase “gluten-free,” “free of gluten,” “without gluten,” or “no gluten” on the product label. The FDA guidelines are based on the standard set forth by Codex Alimentarius.

Food Standard 118-1979, referred to as Standard for Foods for Special Dietary Use for

Persons Intolerant to Gluten, states that gluten-free foods must contain less than 20 mg/kg of gluten (Food and Agriculture Organization & World Health Organization, 2015).

Due to conflicting labeling regulations, certain food products may list wheat in the ingredients list or “contains” statement, while also using a gluten-free label

(Thompson, 2015). Ingredients such as wheat starch and wheat starch derivatives, including maltodextrin and glucose syrup, have been processed to remove gluten. Thus, if the finished product contains less than 20 ppm of gluten, use of the FDA gluten-free label is permitted. However, the Food Allergen Labeling and Consumer Protection Act (U.S.

Food and Drug Administration, 2013) requires that food products containing any form of wheat protein include wheat in either the ingredients list or the “contains” statement.

Therefore, it is possible for a product to have both a gluten-free label and wheat in the

“contains” statement. 28

There are two important explanations for the threshold of 20 ppm. The first reason is that food with less than 20 ppm of gluten has been shown to remain safe for people with celiac disease (FDA, 2013). The second rationale is that it would be extremely expensive for most manufacturers to produce food with such a low level of gluten.

The FDA ruling does not require the use of a specific gluten detection method

(FDA, 2013). However, two sandwich enzyme-linked immunosorbent assay (ELISA) techniques have been evaluated and identified as effective methods for gluten detection.

The recommended methods are the R5-Mendez ELISA and the Morinaga ELISA.

In addition to the FDA labeling regulation, there are multiple independent organizations that will certify products as gluten-free (Thompson & Simpson, 2014).

Three notable organizations are the Gluten-Free Certification Organization (GFCO), the

Gluten-Free Certification Program (GFCP), and the Celiac Support Association (CSA).

Each of these organizations maintains their own standard for the maximum amount of gluten allowable per their certification. The GFCO requires ≤ 10 ppm gluten, the GFCP requires < 10 ppm gluten, and the CSA requires < 5 ppm gluten.

Although the previously mentioned labeling regulations are certainly a step in the right direction, there remains room for improvement. A study quantifying gluten presence in various food products found levels of gluten greater than 20 ppm in 1.1% of gluten- free labeled products (Sharma et al., 2015). Another study analyzing gluten-free products found that 5% of products labeled as gluten-free, but not certified, contained more than

20 ppm gluten (Thompson & Simpson, 2014). Products that were labeled gluten-free and 29 certified gluten-free by an additional organization demonstrated gluten content greater than 20 ppm in 4% of cases.

Gluten-Related Disorders

Celiac disease. Celiac disease is an autoimmune condition characterized by an immune response following the consumption of gluten (Green et al., 2015).

Approximately 1.0% of the Western population suffers from celiac disease. Despite the perception of increased rates of celiac disease, the prevalence has not changed significantly in recent years (Kim et al., 2016). Family members of individuals with diagnosed celiac disease are far more likely to develop the condition themselves, compared to the general population (Rubio-Tapia, Hill, Kelly, Calderwood, & Murray,

2013). First-degree relatives have been estimated to demonstrate rates of celiac disease between 5% and 20%.

Digestion of gluten is impaired in people with celiac disease (Green & Cellier,

2007; Green et al., 2015). The compromised digestion of gluten leads to responses in the adaptive and innate immune systems. The innate immune system is nonspecific and reacts to antigens rapidly; whereas the adaptive immune system response is pathogen- specific and occurs over a much longer time period, sometimes requiring several days

(Ryan, 2015). The location of each immune system’s action also differs; the innate immune system acts primarily in the intestinal epithelium, while the adaptive immune system executes its response in the intestinal lamina propria (Escudero-Hernández, Peña,

& Bernardo, 2016). 30

Gliadin, a component of gluten that is resistant to digestion, remains predominantly unaffected by proteases present in the stomach, pancreas, and intestinal brush-border membrane (Green & Cellier, 2007; Green et al., 2015). The protease resistance is attributed to the high concentrations of proline and glutamine peptides found in gliadin. Endopeptidases present in the intestinal lumen and brush border are ineffective in breaking down proline and glutamine. In addition, the absence of prolyl endopeptidase

(PEP) activity in the intestinal lumen and brush border appears to be at least partially responsible for gliadin’s enzyme-resistance (Heyman, Abed, Lebreton, & Cerf-

Bensussan, 2012). Notably, brush border peptidases incompletely break down gliadin peptides p57-68 and p62-75. Peptide p57-p89, referred to as 33-mer, is entirely unaltered by peptidases. Due to the enzyme-resistance, following consumption of gluten, gliadin stays in the intestinal lumen.

Periods of increased intestinal permeability appear to support the altered gluten digestion observed in celiac disease (Heyman et al., 2012). Permeability may be heightened due to a variety of factors, particularly intestinal infection. During this period of increased permeability, the innate immune system allows gliadin to move through the intestinal epithelial barrier and make contact with the lamina propria (Demin et al., 2013;

Green et al., 2015). Once in the lamina propria, tissue transglutaminase (tTG) deaminates gliadin. This process produces a gliadin fragment with amplified immunogenic characteristics.

In the adaptive immune response, gliadin peptides interact with an antigen- presenting cell (APC) that expresses human leukocyte antigen (HLA) serotypes HLA- 31

DQ2 or HLA-DQ8, in the lamina propria (Ryan, 2015). APCs may exist as macrophages, dendritic cells, and/or B cells (Green et al., 2015). The APC presents the attached gliadin peptide to native CD4+ T cells (Escudero-Hernández et al., 2016). Subsequently, the gliadin fragment activates CD4+ T cells. Activated CD4+ T cells differentiate into T helper 1 (TH1) and T helper 17 (TH17) cells. TH1 and TH17 cells generate an array of inflammatory cytokines. TH1 cells produce interferon- γ (IFN-γ) and TH17 cells produce

IL-21 (Ryan, 2015; Spolski & Leonard, 2014). Unlike IFN-γ and IL-21, IL-15 is produced by intestinal epithelial cells (IECs), rather than T helper cells. These cytokines utilize different methods to cause damage to the intestinal villi and crypt hyperplasia

(Abadie & Jabri, 2014; Ryan, 2015). IFN- γ increases intestinal permeability. IL-21 intensifies and perpetuates the actions of TH1. The innate immune response occurs with increased expression of IL-15 (Green et al., 2015). IL-15 mediates the development of cytotoxic CD8+ T cells from intraepithelial lymphocytes. CD8+ T cells damage the intestinal epithelium by prompting enterocyte apoptosis (Mazzarella et al., 2008).

Symptoms of gluten exposure in untreated celiac disease patients are commonly distinguished as either intestinal or extraintestinal symptoms (Green et al., 2015; Kelly,

Bai, Liu, & Leffler, 2015). Intestinal symptoms often present as diarrhea and/or abdominal discomfort. A frequent extraintestinal symptom is dermatitis herpetiformis, which manifests as an itchy rash, often with blisters. Roughly 25% of patients with celiac disease experience dermatitis herpetiformis (Westerberg et al., 2006). Further extraintestinal symptoms include fatigue, osteoporosis and anemia. In addition, hypertransaminasemia, a state of elevated aspartate aminotransferase and alanine 32 aminotransferase levels, has been reported in up to 42% of adults and 40% of children with celiac disease. Adherence to a gluten-free diet normalizes transaminase levels in between 71% and 79% of patients (Lee, Boyle, Ediger, & Hill, 2016).

Continued ingestion of gluten can cause severe damage to the intestinal villi

(Kelly et al., 2015). The intestinal villi are responsible for nutrient absorption (Stamnaes

& Sollid, 2015). Therefore, damage can lead to malabsorption of nutrients. Iron deficiency is a common nutrient deficit in untreated celiac disease patients. Additionally, folate, zinc, and vitamins D, B6, and B12 deficiencies are observed in many patients with newly diagnosed celiac disease (Kelly et al., 2015).

There is a strong genetic component to celiac disease (Green et al., 2015). The

HLA-DQ2 and/or HLA-DQ8 serotypes exist in essentially every person with celiac disease (Ryan, 2015). However, this is not definitive ground for a diagnosis of celiac disease, as people without celiac disease may also possess one or both of these genes.

Approximately 40% of the population possesses HLA-DQ2 or HLA-DQ8 (Hill et al.,

2016).

Standards for the diagnosis of celiac disease vary; however, they typically involve two steps, serological screening and intestinal biopsies (Kelly et al., 2015; Rubio-Tapia et al., 2013). During the entire process, patients must still be consuming gluten. If the patient is avoiding gluten during testing, the results will be inaccurate. The first diagnostic step is serological screening. To understand the efficacy of various serological tests, it is necessary to first understand the terms sensitivity and specificity. Sensitivity describes the capability of a serological test to accurately detect the presence of a disease 33 or condition (Lalkhen & McCluskey, 2008). Therefore, the higher the sensitivity of a test, the more likely a patient with celiac disease will be diagnosed as having celiac disease.

Specificity is fundamentally the opposite of sensitivity. Specificity is the capacity to properly recognize the absence of a disease or condition. Hence, the higher the specificity, the less likely it is that a patient without celiac disease will be incorrectly diagnosed as having celiac disease.

Immunoglobulin A (IgA) tTG antibody is typically used as the first form of serological testing (Hill et al., 2016; Rubio-Tapia et al., 2013). The tTG IgA test is cost- efficient and has the highest specificity and sensitivity among all celiac disease tests.

Endomysial antibodies (EMA) IgA is another serological test that may be employed.

EMA IgA yields sensitivity and specificity comparable to tTG IgA; however, this test is subject to interpretation by the test administrator (Gujral, Freeman, & Thomson, 2012).

Therefore, tTG IgA remains the first method of serological testing. However, due to the presence of IgA deficiency in 2-3% of patients with celiac disease, additional serological tests are also utilized (Rubio-Tapia et al., 2013). If IgA deficiency is suspected, total IgA is assessed. In cases of confirmed IgA deficiency, immunoglobulin G (IgG)-based tests are implemented. TTG IgG and deaminated gliadin peptide (DGP) IgG are the next line of testing. The DGP IgG test is less sensitive than the tTG IgA, which is why it is not used as an initial method of diagnosis. If serological tests are positive or celiac disease is still suspected, the next step is an intestinal biopsy.

Intestinal biopsies are the gold standard for diagnosing celiac disease (Hill et al.,

2016; Rubio-Tapia et al., 2013). The American College of Gastroenterology (ACG) and 34 the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition

(NASPGHAN) recommend that patients undergo at least four biopsies from the distal duodenum and at least one from the duodenal bulb. Marsh classification is a commonly used method for identifying histological alterations in celiac disease (Green, Rostami, &

Marsh, 2005). Biopsies are categorized as Marsh I, Marsh II, Marsh III A, Marsh III B, or

Marsh III C. Intraepithelial lymphocytosis is present in all Marsh classifications.

Intraepithelial lymphocytosis is defined as greater than 30 lymphocytes per 100 enterocytes. Marsh I is indicated when villous structure remains normal. Marsh II is classified by the manifestation of crypt hyperplasia. Marsh III A, B, and C are indicated by the increasing severity of villous atrophy, with Marsh C being the most extreme form.

At present, there is no cure for celiac disease (Kelly et al., 2015). The only effective treatment for celiac disease is compliance to a gluten-free diet, which can be extremely challenging, as wheat, rye, and barley are highly prevalent in the American diet (Rubio-Tapia et al., 2013). Following compliance to a gluten-free diet, the intestinal tract rebuilds itself and symptoms subside (Rubio-Tapia et al., 2013; Stamnaes & Sollid,

2015). The repaired intestinal villi allow the return of normal nutrient absorption.

Research is currently underway to create a medication to use as a treatment for celiac disease patients. Various enzymes are being investigated for their effectiveness as glutenases (Stoven, Murray, & Marietta, 2012). Glutenases are enzymes with the ability to break down proline and glutamine fragments within gluten. Ideally, glutenases are capable of being taken as oral supplements. Many peptidases have demonstrated efficacy in degrading the proline and glutamine fragments. Unfortunately, the majority of these 35 peptidases are unable to remain active once exposed to pepsin and the acidic environment of the stomach. ALV003 and AN-PEP are key examples of potentially effective glutenases being studied.

ALV003 is a blend of two distinct glutenases (Makharia, 2014; Stoven et al.,

2012). A cysteine endoprotease originating from barley, referred to as EP-B2, is the first component of ALV003. The remaining glutenase is a PEP derived from Sphingomonas capsulata (SC-PEP). ALV003 has been shown to significantly decrease activation of

INF-γ following consumption of 16 g of gluten in celiac disease patients, compared to a placebo (Tye-Din et al., 2010). However, this study failed to demonstrate any significant improvements in symptoms after gluten meals pre-treated with ALV003.

As previously discussed, the absence of PEP in the intestinal brush border may contribute to the gliadin-resistance observed in celiac disease patients (Heyman et al.,

2012). Therefore, AN-PEP, a prolyl endopeptidase originating from Aspergillus niger, is being investigated extensively as a potential treatment for celiac disease (Makharia, 2014;

Stoven et al., 2012).

Nonceliac gluten sensitivity. Nonceliac gluten sensitivity (NCGS) is a topic of substantial controversy in the scientific community (Fasano, Sapone, Zevallos, &

Schuppan, 2015). There is considerable disagreement about NCGS and whether it should be recognized as a legitimate clinical condition. Individuals with NCGS demonstrate negative responses following consumption of gluten. Prevalence of NCGS is unknown, for two key reasons. First, many individuals diagnose themselves with the condition and implement a gluten-free diet without seeking medical attention (Vazquez-Roque & 36

Oxentenko, 2015). Second, there is no standardized set of guidelines for diagnosing

NCGS.

The pathogenesis of NCGS is not currently understood, but research continues to elucidate possible etiologies (Vazquez-Roque & Oxentenko, 2015). The innate immune system has been investigated for its possible involvement in NCGS (Junker et al., 2012).

A study by Sapone et al. (2010) examined expression of transcripts for the cytokine IL-17 in patients with celiac disease, NCGS, and dyspeptic controls. They found that there was a significant increase in the expression of IL-17 in celiac disease patients compared to

NCGS patients and controls. These results support the theory that NCGS involves the innate immune system, rather than the adaptive immune system, as IL-17 is a marker of adaptive immunity. Additionally, intestinal permeability of all three groups was evaluated in the same study. NCGS individuals had significantly reduced permeability compared to both celiac disease patients and controls. Reduced permeability distinguishes NCGS from celiac disease, which is characterized by increased intestinal permeability.

Wheat α-amylase/trypsin inhibitors (ATIs), which are nongluten constituents of wheat, have been examined in potentially provoking an innate response through activation of toll-like receptor 4 (TLR4) (Junker et al., 2012). This is a prominent theory being explored for its possible involvement in the pathogenesis of NCGS; however, very little is still known about this mechanism. More research needs to be done to provide sufficient evidence for the pathogenesis of NCGS.

Symptoms of NCGS may be intestinal and/or extraintestinal in nature (Fasano et al., 2015; Vazquez-Roque & Oxentenko, 2015). Intestinal symptoms can include 37 abdominal discomfort, nausea, diarrhea, bloating, and constipation. Extraintestinal symptoms often include fatigue, eczema, joint pain, headaches, and numbness of the extremities.

There is no specific set of diagnostic criteria for NCGS; however, it is generally diagnosed when symptoms observed following gluten ingestion appear to improve on a gluten-free diet and the possibilities of both celiac disease and wheat allergy have been eliminated (Fasano et al., 2015; Vazquez-Roque & Oxentenko, 2015). Unlike celiac disease, serological tests have yet to be identified for testing of NCGS (Hill et al., 2016).

In addition, those who suffer from NCGS do not present with villous atrophy or crypt hyperplasia as in cases of celiac disease. Double-blind gluten challenges have been proposed to counteract the possibility of a placebo effect during diagnosis (Czaja-Bulsa,

2015; Elli, Roncoroni, & Bardella, 2015). In this practice, patients believed to have

NCGS undergo a gluten challenge while following a gluten-free diet. Specifics regarding the challenge such as dosage, period of time on gluten-free diet, and medium of gluten delivery have not been standardized.

Treatment, as with diagnosis, for apparent NCGS has not been established as standard guidelines (Elli, Roncoroni, et al., 2015). Despite this, a gluten-free diet is the consistent choice for treatment. Some research suggests slowly reintroducing gluten into the diet, following a period of no gluten consumption.

Wheat allergy. Wheat allergy is one of the more common food allergies, with

0.1% of the population diagnosed (Pietzak, 2012). Wheat allergy is usually seen in children rather than adults, as most outgrow the condition by adulthood. The method of 38 allergen contact determines how wheat allergy is categorized. Occupational asthma and rhinitis, food allergy (FA), wheat-dependent exercise-induced anaphylaxis (WDEIA), and contact urticaria are the subcategories included under the umbrella of wheat allergy (Elli,

Branchi, et al., 2015; Inomata, 2009).

Wheat contains numerous proteins, of which only a portion are allergenic (Van

Rooyen & Van den Berg, 2015). The World Health Organization (WHO)/International

Union of Immunological Societies (IUIS) Allergen Nomenclature Database lists 27 allergens present in wheat. Tri a 19, also known as ω-5 gliadin, is one of the key allergens in wheat; it is linked to FA and WDEIA (Lehto et al., 2003; Van Rooyen & Van den

Berg, 2015). Tri a 20, γ-gliadin, is connected to FA and occupational asthma (Matsuo,

Yokooji, & Taogoshi, 2015). Tri a 21, α/β-gliadin, is involved with FA, occupational asthma, and WDEIA. Tri a 26, HMW-GS, may be a related to WDEAI. Tri a 36, LMW-

GS, is linked to FA and WDEIA. The gluten components previously described are specific to wheat, allowing sufferers of wheat allergy to safely consume barley and rye.

Nongluten components of wheat, ATIs, have been associated with occupational asthma

(Pasha et al., 2016).

Symptoms of wheat allergy frequently include itching and swelling of the mouth, eyes, throat and nose; a rash and hives on the skin; respiratory distress and anaphylaxis; and abdominal pain, nausea, diarrhea, vomiting, and bloating (Pietzak, 2012). However, symptoms may vary depending on the category of wheat allergy. Occupational asthma, often referred to as baker’s asthma, presents with typical asthmatic symptoms (Talini et al., 2002). Respiratory distress in the form of coughing and difficult breathing is 39 common. Rhinitis and irritation of the eyes and skin have also been observed in baker’s asthma (Pasha et al., 2016). FA symptoms involve a wide array of reactions, including atopic dermatitis, erythema, urticaria, gastrointestinal responses, rhinitis, angioedema, and anaphylaxis. WDEIA may result in urticaria, difficulty breathing, hypotension, or shock (Inomata, 2009). Contact urticaria is associated with skin-related symptoms such as pruritus, an itching sensation; generalized urticaria, also known as hives; and wheal and flare reactions. Anaphylaxis may also occur as a result of contact urticaria (Scherf,

Koehler, & Wieser, 2016).

A specific IgE blood test and/or skin prick tests are used as the first step for diagnosing wheat allergy (Elli, Branchi, et al., 2015). However, these methods do not produce ideal sensitivity or specificity (Hill et al., 2016). Sensitivity of IgE testing for wheat allergy is approximately 83%, while specificity is only 43%. Skin prick tests involve depositing the allergen directly on the skin, and puncturing the area to allow the allergen to enter through the skin. Sensitivity and specificity of the wheat allergy skin prick test are both 73%. In cases where serological and skin prick tests are inconclusive, functional tests are used. Functional tests are the gold standard for confirming a wheat allergy diagnosis (Elli, Branchi, et al., 2015). Bronchial challenge and double-blind placebo controlled oral challenges (DBPCOCs) are the functional tests used to diagnose baker’s asthma and FA, respectively. A bronchial challenge is conducted by having participants inhale flour dust through a mouthpiece (Talini et al., 2002). The mouthpiece is attached to a container, which is used to measure forced expiratory volume after varying levels of exposure to the flour dust. In a DBPCOC, the patient is given either a 40 food that contains wheat, or a seemingly identical food that does not contain wheat

(Scibilia et al., 2006). The wheat-containing food is administered with increasing doses of wheat. After each dose, the patient is evaluated for reactions.

Gluten-Free Diet

As previously stated, celiac disease and NCGS can only be treated with a gluten- free diet (Elli, Roncoroni, et al., 2015; Rubio-Tapia et al., 2013). Individuals who are required to follow a gluten-free diet must fully grasp the extent of this dietary restriction; which is more complex than looking for wheat, rye, or barley on an ingredient list. Items such as malt, durum, kamut, semolina, spelt and triticale contain gluten (Case, 2005).

Due to this complication, many people unintentionally consume gluten (Silvester et al.,

2016).

There is discussion among researchers concerning whether oats should be included in a gluten-free diet (Dessì et al., 2013). However, as previously discussed, the composition of oats differs greatly from that of wheat, rye, and barley. Therefore, in regard to potential toxicity in susceptible individuals, oats are considered a gluten-free grain. Inclusion of oats in a gluten-free diet has been shown to be safe, so long as the oats remain uncontaminated by wheat, rye, or barley (Rubio-Tapia et al., 2013).

Uncontaminated oats, often referred to as pure oats, are available commercially on their own or as an ingredient in specialty gluten-free products (See et al., 2015). The ACG recommends slowly incorporating pure oats into the diet (Rubio-Tapia et al., 2013). As oats are reintroduced into the diet, individuals should be cognizant of any negative responses occurring at this time. 41

Cross-contact with gluten is a concern for any person following a gluten-free diet.

Contact of food with gluten can occur in a number of situations (See et al., 2015). Food may be unintentionally exposed to gluten while being harvested in the field, during retail processing, during preparation at a restaurant, or within the home. There are a variety of methods to avoid cross-contact within the home (Dessì et al., 2013). First, gluten-free and gluten-containing food should be stored in separate locations. Additionally, when serving both gluten-containing and gluten-free foods at home it is important to use different serving utensils for the gluten-free food. A form of cross-contact within the home that may be overlooked is the use of only one toaster. Households containing at least one individual following a gluten-free diet need a toaster designated for gluten-free food.

RDs must be equipped with sufficient knowledge of a gluten-free diet in order to provide optimal care to patients with celiac disease and nonceliac gluten sensitivity

(Case, 2005; See et al., 2015). Patients benefit from nutrition education for topics including, but not limited to, sources of gluten in the diet, reading a nutrition facts label, eating out, and cross-contact.

The RD should continually monitor and evaluate the nutritional status of patients, as a gluten-free diet is associated with numerous nutritional risks (See et al., 2015). Key risks when following a gluten-free diet include insufficient fiber, iron, and B vitamins.

Because of these potential nutrients at risk, it is important to replace gluten-containing foods with nutritionally comparable gluten-free substitutes. Brown rice, quinoa, buckwheat, amaranth, and teff are examples of suitable nutrient-dense, gluten-free grains

(EAL, 2009). 42

Furthermore, gluten-free diets are often higher in fat and cholesterol (See et al.,

2015). The increased intake of fat and cholesterol occurs for multiple reasons. In an attempt to improve taste and texture, specialty gluten-free products often contain more fat and sugar than comparable gluten-containing products. Additionally, when commonly consumed grains are removed from the diet, people are likely to replace formerly consumed grains with meat, eggs, and cheese.

Psychosocial assessment is an aspect of nutrition education that may be forgotten in patients following a gluten-free diet (See et al., 2015). It is important to determine obstacles the patient may face, as well as identify the patient’s psychosocial support system. It is common for individuals to perceive pressure in their social lives regarding their gluten-free diet (Silvester, Weiten, Graff, Walker, & Duerksen, 2015). The desire to eat similarly to friends and family can negatively impact adherence to the prescribed diet.

By addressing these concerns, the patient is far more likely to follow their gluten-free diet.

Despite the frustrations that accompany a gluten-free diet, it is gaining substantial traction among the general public. Online searches for “gluten free” increased drastically from 2004 to 2015, while searches for “celiac disease” remained stable (Reilly, 2016).

Data collected between 2013-2014 from the National Health and Nutrition Examination

Surveys (NHANES) found that 1.69% of the population above 6 years of age without celiac disease reported avoiding gluten (Kim et al., 2016).

The dramatic increase in public popularity is likely linked to celebrity testimonials of the diet’s supposed health benefits (Gaesser & Angadi, 2012). Gwyneth 43

Paltrow is a celebrity that frequently endorses the gluten-free diet for the general public

(Rousseau, 2015). Actress Jenny McCarthy has written a book touting the supposed efficacy of a gluten-free, casein-free diet for treating and preventing autism (McCarthy &

Kartzinel, 2009). However, research has shown no conclusive evidence to support the use of this diet as a treatment or preventative measure for autism (Mulloy et al., 2010).

Despite the public’s view, there is no scientific evidence to prove that a gluten- free diet is superior to a gluten-containing diet or will result in weight loss among those without celiac disease or NCGS (Gaesser & Angadi, 2012). Individuals may in fact gain weight on a gluten-free diet due to the potentially inadequate intake of whole grains and fiber.

Chapter 3: Knowledge and Perceptions of a Gluten-Free Diet: A Mixed Methods

Approach1

Abstract

Background: The practice of gluten-free diets is on the rise, yet many people are still unaware of what gluten is and how it functions in food. It is important that food and nutrition professionals are knowledgeable in this topic due to the prevalence of gluten- related disorders and popularity of gluten-free as a fad diet.

Objective: The purpose of this research was to use a mixed methods approach using qualitative and quantitative methods to obtain and evaluate knowledge and perceptions of a gluten-free diet from future and current food and nutrition professionals.

Design: Focus groups on the topic of gluten-free, consisting of former Food Science students, faculty, and/or other nutrition professionals were conducted. Thematic analysis was used to determine key concepts generated from the focus groups, and foster the formation of a questionnaire. The questionnaire was distributed to Registered Dietitians to assess their knowledge and attitudes towards the gluten-free diet.

Participants/setting: Registered Dietitians nationwide completed the questionnaire (n =

516).

1 This chapter has been formatted as a manuscript to submit for publication to the Journal of the Academy of Nutrition and Dietetics. Authors are Hannah Johnson (School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens, OH), with Elizabeth Beverly (Assistant Professor, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH), Deborah Murray, MS, RD, (Associate Lecturer, School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens, OH, and Robert Brannan, PhD (Associate Professor, School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens, OH).

Main outcome measures: Perceptions of a gluten-free diet were identified in nutrition students. Knowledge and attitudes of a gluten-free diet were determined in Registered

Dietitians.

Statistical analyses performed: A one-way ANOVA and descriptive tests were used to analyze questionnaire responses.

Results: Over 18% of respondents incorrectly identified gluten as a carbohydrate.

Additionally, less than 80% of RDs correctly identified the presence or absence of gluten in semolina, spelt, kamut, and buckwheat. Regarding perceptions of a gluten-free diet, participants reported that the public is not aware of what gluten is, a gluten-free diet is not appropriate for the general public or weight loss, and the gluten-free diet is a fad when used outside of celiac disease and nonceliac gluten sensitivity.

Conclusions: There is a need for improved education of a gluten-free diet in the areas of sources of gluten, labeling, and gluten-related disorders among Registered Dietitians.

Introduction

There is an increasing demand for gluten-free products, as evidenced by a rise in both the retail sales and consumption of gluten-free products in recent years (Roberts,

2016). A recent survey reported that of the population consuming gluten-free products,

(NHANES) found that 1.69% of the population above 6 years of age without celiac disease reported follow a gluten-free diet (Kim et al., 2016). Research suggests that an increase in public popularity of gluten-free diets likely is linked at some level to celebrity testimonials of the diet’s supposed health benefits, especially weight loss (Gaesser &

Angadi, 2012). However, there is no scientific evidence to prove that a gluten-free diet will result in weight loss among those without celiac disease. Individuals may in fact gain weight on a gluten-free diet due to the nutritional inadequacy of many gluten-free products.

(Silvester, Weiten, Graff, Walker, & Duerksen, 2016). In 2013, the U.S. Food and Drug

Administration (FDA) released a set of guidelines for labeling products as gluten-free

Registered Dietitians (RDs) must be equipped with sufficient knowledge about a gluten-free diet in order to provide optimal care to patients with celiac disease and nonceliac gluten sensitivity (Case, 2005; See, Kaukinen, Makharia, Gibson, & Murray,

2015). Patients need to receive education for topics including, but not limited to, sources of gluten in the diet, reading a nutrition facts label, eating out, and cross-contact.

Currently, there is no existing research exploring the knowledge of gluten and the gluten-free diet of RDs, to the best of the researcher’s knowledge. This research will be the first to establish the current knowledge and perceptions of gluten and a gluten-free diet in nutrition students and RDs. The results of this research will determine if there is a need for further education of gluten and the gluten-free diet in the field. Additionally, this research will provide information for the improvement of current educational materials.

The purpose of this research is to employ a mixed-methods approach using qualitative and quantitative methods to obtain and evaluate knowledge and perceptions of gluten and a gluten-free diet from current and future nutrition professionals.

Materials and Methods

Focus groups. Three focus groups were conducted to acquire insight into the knowledge and perceptions of gluten and gluten-free from people studying and/or 48 working within the nutrition field. Participants recruited for the focus groups consisted of undergraduate Applied Nutrition students in the Dietetics concentration, graduate students majoring in Food and Nutrition Sciences, and nutrition faculty members at Ohio

University. Participants were recruited via an email invitation. A total of 26 individuals participated in the focus groups.

The researcher obtained signed consent from all participants before beginning the focus groups (see Appendix B). The researcher and advisor moderated the focus groups together. Each focus group lasted approximately 45 minutes, according to a plan developed before the focus group (see Appendix C). Topics including knowledge of gluten, impressions of gluten-free diets/products, and the application of this information into a laboratory were discussed. Focus groups were audiorecorded to allow for transcription to text.

Thematic analysis was used to determine key concepts generated from the focus groups. Using NVivo 11 software (QSR International, Victoria, Australia [Released

2015]), the researcher read each transcript and identified common topics. The most frequent topics were transformed into codes. The codes allowed for the discovery of key themes discussed throughout the focus group. Codes included, but were not limited to, gluten information, gluten-related disorders, public awareness, education, labeling, gluten-free diet, and quality concerns in gluten-free products.

Questionnaire. A questionnaire targeted to RDs was developed using data from the focus group themes. The objective of the questionnaire was to assess the knowledge and attitudes of gluten and a gluten-free diet in RDs. The researcher created the 49 questionnaire through Qualtrics, an online data collection and analysis software, and distributed via email (see Appendix D).

The questionnaire was first piloted with RDs at Ohio University. Online consent was obtained before beginning the questionnaire (see Appendix E). Participants were given the opportunity within the pilot questionnaire to leave feedback regarding suggestions for improvements. Nine RDs completed the pilot questionnaire. Following the pilot questionnaire, necessary changes were made and submitted to the IRB for approval. Upon approval, the researcher submitted a request to the Commission on

Dietetic Registration (CDR) for use of database information. Once approved, CDR provided a list of contact information for RDs. The list included a random sample of

5,000 of the overall registry of approximately 97,000 RDs. The provided contacts were used as the research sample. As with the pilot sample, RDs were recruited via email. The email contained a link to the Qualtrics questionnaire. The questionnaire was available online for email recipients to complete within a 17-day period.

Hedonic questions included in the questionnaire are listed in Table 2. Hedonic questions were rated on a 1-5 scale, with 1 representing “strongly disagree”; 2, “slightly disagree”; 3, “neither agree or disagree”; 4, “slightly agree”; and, 5, “strongly agree.”

Respondents were asked to identify the state in which they reside. From this information, participants were further categorized into one of four regions (Northeast,

Midwest, South, and West), according to the U.S. Census Bureau (1994).

Data from the questionnaire was analyzed to establish measures of central tendency of responses for each question. A one-way ANOVA was used to analyze 50 hedonic questions. Descriptive analyses were used to provide basic response sums for all questions.

Results and Discussion

Focus groups. The focus group discussions, which included undergraduate and graduate nutrition students and RDs, covered a variety of gluten-related topics.

Comments made by focus group participants were classified into one of seven categories: gluten information, public awareness, labeling, gluten-free diet, quality, gluten-related disorders, and education. The comments within each category are explained in detail below and summarized in Table 1.

Regarding responses about the category gluten information, participants were aware that gluten is a protein found in wheat, rye, and barley. One participant specifically mentioned that gliadin and glutenin are two of the main components of gluten. When asked to provide a single word for gluten’s function in food, words including “structure” and “texture” were frequently named. Participants agreed that products containing gluten tend to have appealing textures. Overall, current and aspiring RDs were familiar with the basic information surrounding gluten.

However, focus group participants stated that the category public awareness is central to the topic of a gluten-free diet. Despite the growing popularity of the gluten-free diet, focus group participants thought that most of the public is unaware of what gluten is.

One participant said, “I feel like people don’t know what gluten is. I mean, we’re just very uneducated as a society in my opinion.” Numerous participants recognized a common misperception that gluten is a carbohydrate, when it is actually a protein. 51

Participants also expressed frustration because they believe the public is receiving nutrition information from social media that a gluten-free diet can be used for conditions other than celiac disease or NCGS. Participants perceived the gluten-free diet as a fad when used in circumstances other than celiac disease or NCGS. Related to this, the participants felt that there is a lot of misinformation from celebrities and the media telling the public that gluten is something to avoid. Participants described how celebrities are following gluten-free diets and attributing their weight loss to this diet. In general, participants acknowledged that the public is receiving their nutrition information from noncredible sources. Therefore, RDs should be aware of the influence that the media has on the public and use scientifically based information to educate the public on the appropriate uses for a gluten-free diet, which include celiac disease and NCGS.

To alleviate consumer confusion, focus group participants identified the category gluten-free labeling as one that may help those new to a gluten-free diet. Participants stated that if a product has the words gluten-free on the package, it is much easier to find acceptable options for those following a gluten-free diet. In spite of this, there was debate about the use of gluten-free labels, mostly relating to the use of a gluten-free label on products that have always been gluten-free. Participants used guacamole as an example, because it is correct to say that this product is gluten-free, but most participants thought that customers might think that the guacamole has been reformulated from a version that previously contained gluten. This can lead to further confusion about whether other brands of guacamole contain gluten. A participant identified that a positive aspect to gluten-free labels on traditionally gluten-free products is the simplicity for consumers. 52

While a gluten-free label may offer convenience for those following a gluten-free diet,

RDs should educate their patients on how to read an ingredient list (See et al., 2015).

The implications of living on a gluten-free diet beyond gluten-free labels were discussed during the focus groups in the category gluten-free diet. Most participants agreed that the best gluten-free diet is one that utilizes naturally gluten-free items rather than specially made products, i.e., products that typically contain gluten but have been reformulated to be gluten-free. The ideal gluten-free diet, according to focus group participants, contains food such as rice, quinoa, nuts, legumes, fruits, and vegetables.

This is in agreement with the current literature, which recommends that a gluten-free diet be supplemented with nutrient dense grains to counteract the loss of otherwise acquired nutrients such as fiber, B vitamins, and iron from wheat, rye, and barley (See et al.,

2015). Gluten-free grains including quinoa, brown rice, and oats are beneficial in adding these nutrients to the diet. Similar to the recommendations for a generally healthful diet, fruits and vegetables should be included in a gluten-free diet. Participants stated that an issue with following this form of a gluten-free diet is that it is more time consuming than a gluten-free diet that utilizes an abundance of convenient specialty products. Overall, most participants agreed that the ideal, nutritionally adequate gluten-free diet uses mostly naturally gluten-free products, and limits use of specialty products.

However, focus group participants acknowledged the use of convenience specialty products and that quality issues are common concerns in these products, as noted in the category quality. One participant stated, “I think there is still a perception that some foods don’t taste as good when they’re gluten-free.” Participants noted that 53 although the quality of these products has improved, there is room for further progress, especially in the areas of excess chewiness, denseness, and the lack of structure that exists in many products on the market. Participants were concerned that that food manufactures add excess sugar and fat in order to improve the taste of items have compared to their gluten-containing counterparts. The addition of these ingredients creates products that can negatively affect the health of the consumer (Pellegrinia &

Agostoni, 2015; Vici, Belli, Biondi, & Polzonetti, 2016). Despite this, participants agreed that the demand for gluten-free products has increased in recent years, an observation supported by a 2016 Mintel report, which stated that retail sales of gluten-free products increased from approximately $5 million in 2013, to $13.6 million in 2016 (Roberts,

2016). Participants thought that grocery stores have spaces dedicated to convenient specialty gluten-free products to create competition between convenient specialty gluten- free items and traditional gluten-free foods. RDs should be aware of the quality differences in gluten-free products, both sensory and nutritionally, to educate their patients/clients on a gluten-free diet about which products may be appropriate to integrate into their diet.

Regarding responses about the category gluten-related disorders, celiac disease and nonceliac gluten sensitivity were topics of interest throughout the focus groups.

Participants were aware that celiac disease is an autoimmune disorder in which gluten cannot be properly digested and that if gluten is consumed, patients will experience negative side effects. Participants were in agreement that the only treatment is a gluten- free diet and that patients with celiac disease should work closely with an RD as part of 54 their treatment, which is consistent with the current recommendations (Rubio-Tapia, Hill,

Kelly, Calderwood, & Murray, 2013; See et al., 2015). This result is not surprising, because the focus group participants were current or aspiring RDs. Some participants thought that, due to the increased awareness of celiac disease, physicians have become more efficient in diagnosing celiac disease, thus leading to increased prevalence.

However, the research has shown that the prevalence of celiac disease, approximately

0.5-1.0% of the population, has not changed significantly in recent years (Kim et al.,

2016). Participants mentioned that some individuals claim to experience negative side effects following consumption of gluten, despite not having been diagnosed with celiac disease. Participants acknowledged the inconsistency in the definition of this condition, frequently referred to as nonceliac gluten sensitivity (NCGS). This is in agreement with the current literature, which typically identifies a patient as having NCGS when the possibility of celiac disease and wheat allergy have been eliminated and symptoms are alleviated on a gluten-free diet. However, there are currently no diagnostic tests specific to the NCGS. Some participants thought that people with NCGS might be able to consume small amounts of gluten without having a reaction. Overall, participants identified celiac disease and NCGS as the primary disorders within the category of gluten-related disorders. RDs should treat both celiac disease and NCGS with a gluten- free diet and routine follow-up appointments.

Throughout the focus groups, participants stated that it is important for nutrition students to understand gluten and the gluten-free diet, described in the category education. Key pieces of information about gluten were identified by the focus group 55 participants as being necessary for nutrition students to know, including familiarity with what gluten is, sources in the diet, and functionality in food. Additionally, participants stated that it is important to understand the differences in how gluten is digested in a typical person versus someone with celiac disease. It is essential that students recognize the nutritional differences in gluten-containing products compared to gluten-free products

(See et al., 2015). One participant detailed, “If you’re going to work in a restaurant or you’re going to be a dietitian you need to know about gluten and gluten-free products.”

Comprehension of the functionality of various gluten-free substitutes, particularly flour, was frequently described as being important. This knowledge allows professionals such as RDs to provide useful education for patients/clients following a gluten-free diet.

The focus group results demonstrated that participants were aware of many key issues concerning the gluten-free diet, including public awareness, gluten-related disorders, and labeling. This information was of great value in determining topics to include in the gluten-free questionnaire for RDs. For example, gluten-free labeling, a topic with many grey areas, was identified as an interesting topic to assess in a representative sample of RDs. Focus group participants determined that it is important for

RDs to be knowledgeable in celiac disease. Therefore, assessing RDs basic knowledge of celiac disease was recognized as an important topic for the questionnaire.

Questionnaire. A representative sample obtained from CDR of 516 RDs across the United States completed the questionnaire on gluten and a gluten-free diet, which was developed based on feedback from the previously described focus groups. As previously described, the questionnaire was first piloted with 9 local RDs who provided feedback for 56 the improvement of the questionnaire. Demographic characteristics of participants are summarized in Table 3. Overall, the questionnaire participants skewed female (97%) and white (94%), but were evenly distributed across age, years of experience, region, and whether their practice includes celiac disease. Slightly more than half (56%) of respondents possessed a Bachelor’s degree or higher education. Responses were received from all states. However, only a single response was received from Alaska, Hawaii, New

Mexico, Rhode Island, South Dakota, Vermont, West Virginia, and Wyoming; for this reason, these states were removed from the sample set because they did not provide a statistically accurate sample of the state.

Over 81% of RDs stated that gluten is classified as a protein, while 18.5% incorrectly stated that gluten is a carbohydrate. It is very surprising that nearly 1 in 5 RDs were unaware that gluten is a protein and demonstrates a need for education on the most basic aspects of gluten and a gluten-free diet. This result agrees with the feedback of the focus groups, in which participants stated that there is a misconception about what gluten is, with many believing that gluten is a carbohydrate.

There did not appear to be a misconception concerning the presence of gluten in wheat, rye, and barley (see Table 4), as gluten in wheat, rye, and barley was correctly identified by 100%, 88.2%, and 87% of RDs, respectively. However, there may have been a misconception about the presence of gluten in semolina, spelt, and kamut, as gluten was correctly identified by 71.9%, 51.8%, and 37.6% of RDs, respectively. It is not surprising that the food to be correctly identified most often was wheat, as most focus group participants were aware that gluten is present in wheat. Additionally, the more 57 commonly known foods (wheat, rye, barley) were correctly answered at a higher rate than less commonly known foods (semolina, spelt, kamut). Similarly, there did not appear to be a misconception about the absence of gluten in corn, brown rice, quinoa, teff, or amaranth, as the absence of gluten was correctly identified in these foods by

98.8%, 96.3%, 95.7%, 89.2%, and 88.2% of RDs, respectively. However, there may have been confusion about the absence of gluten in buckwheat, as the absence of gluten was correctly identified by only 57.9% of RDs. The confusion about buckwheat being gluten- free might be due to participants’ assumption that buckwheat is a type of wheat. Gluten

(and its sources) is one of the most important aspects of a gluten-free diet. If the RD is unaware of dietary sources of gluten, the patient/client on a gluten-free diet is unlikely to be successful. However, secondary to knowledge of sources of gluten is knowledge of gluten’s function in food.

Responses to the open-ended question “Using a single word, describe the function of gluten in baked goods” were categorized by the researchers into one of seven categories: structure, elasticity, binding, texture, leavening, protein, or other. Thirty-eight percent of participants identified gluten’s function as structure, 25% said elasticity,

14.8% said binding, 11.8% said texture, 6.3% said leavening, 2% said protein, and 2.2% identified a function outside of the given categories. These results reflect that of the focus groups, where participants frequently named structure and texture as a word to describe gluten’s function in food.

It is not unexpected that words describing structure and texture were used by focus group and questionnaire participants because there is significant research to support 58 the claim that the texture and structure of gluten-free products are different than their gluten-containing counterparts. Research with products such as biscuits, cakes, cookies, and muffins has demonstrated that texture and structure differences frequently occur when creating gluten-free products (Alencar, Steel, Alvim, de Morais, & Bolini, 2015;

Goswami, Gupta, Mridula, Sharma, & Tyagi, 2015; Inglett, Chen, & Liu, 2015; Kaur,

Sandhu, Arora, & Sharma, 2015). Gluten-free products can often be crumbly and lack the desired structural stability (Zannini, Jones, Renzetti, & Arendt, 2012). The quality issues that exist in many gluten-free products are probably frustrating to those following a gluten-free diet.

Participants were presented with the question “In your professional opinion, which population(s) should follow a gluten-free diet?” Respondents were able to select one or multiple options for this question (see Table 5). Of respondents, 99.4% identified celiac disease as a condition requiring a gluten-free diet. In addition, 71.5% chose nonceliac gluten sensitivity; 49.8%, wheat allergy; 12.4%, irritable bowel syndrome;

12.4%, Crohn’s disease; 10.4%, autism; and, 3.9%, type 1 diabetes. Nearly all respondents identified celiac disease as a condition requiring a gluten-free diet, perhaps because this claim is supported by the Evidence Analysis Library (Academy of Nutrition and Dietetics, 2009). Although no standard guidelines exist for the treatment for NCGS has not been established as standard guidelines, a gluten-free diet is the consistent choice for treatment (Elli, Roncoroni, & Bardella, 2015). Some research suggests the benefit of slowly reintroducing gluten into the diet, following a period of no gluten consumption.

Although treatment for wheat allergy involves the elimination of wheat from the diet, the 59 treatment does not exclude other gluten-containing grains (Pietzak, 2012). Therefore, a wheat-free diet is not necessarily a gluten-free diet. Although there has been research investigating the effectiveness of a gluten-free diet as a treatment method for irritable bowel syndrome, the results are not definitive (Ruepert et al., 2011). The Nutrition Care

Manual (Academy of Nutrition and Dietetics, 2017) describes the treatment for irritable bowel syndrome as “highly individualized and require goals set by the patient and registered dietitian with consistent follow-up for additional interventions as needed.”

Similar to research about irritable bowel syndrome, research investigating the gluten-free diet as treatment for Crohn’s disease has been inconclusive. The current guidelines for treatment of Crohn’s disease include a low-fiber diet during periods of exacerbation.

Over 10% of respondents identified autism as a population that should follow a gluten- free diet; however, there is very little research to support this claim (Cruchet, Lucero, &

Cornejo, 2016). Overall, RDs should be aware that celiac disease and NCGS are the only conditions with substantial research to support the use of a gluten-free diet.

The questionnaire included basic questions about celiac disease. Participants were asked to identify if celiac disease is an allergy, autoimmune condition, hormone disorder, or metabolic disease (see Table 6). Of respondents, 90.7% correctly identified celiac disease as an autoimmune condition. The method for diagnosing celiac disease was asked

(see Table 7), and 80.1% of respondents selected an intestinal biopsy as the correct diagnostic method for celiac disease. Participants were also asked to identify what percentage of the American population is diagnosed with celiac disease in an open-ended text box (see Table 8). Of the responses, 35.8% ranged from a prevalence of 0.01% to 60

2.0%. These results demonstrate that although participants understand the definition and diagnostic method for celiac disease, there is room for growth in RDs knowledge of prevalence, which is estimated to be 0.5-1.0% (Kim et al., 2016). It is possible that due to the increased popularity of the gluten-free diet, RDs are under the impression that the prevalence of celiac disease is much higher.

A portion of the questionnaire consisted of 14 statements that RDs rated on a hedonic scale (1 = strongly disagree; 2 = slightly disagree; 3 = neither agree nor disagree;

4 = slightly agree; 5 = strongly agree), shown in Figure 1. Overall, the RDs agreed with seven statements and disagreed with seven statements. Of the seven statements on which the RDs agreed (hedonic score > 3), three of these had overall means greater than 4.

When presented with the statement “A gluten-free diet is appropriate for the general population,” overall, RDs disagreed with the statement (M = 1.56). There was a significant difference in the mean score for age groups (p = 0.003) and years as an RD (p

= 0.007). Respondents who were 45-54 years old (M = 1.87) were less likely to disagree as compared to respondents who were 25-34 years old (M = 1.2) and 55-64 years old (M

= 1.45). Respondents who have been RDs for 0-4 years (M = 1.44), who are likely to be in the 25-34 years old range, and 40+ years (M = 1.15), who are likely to be in the 55-64 years old range, also strongly disagreed with the statement. Respondents that have been

RDs for 20-29 years (M = 1.86) disagreed with the statement less than respondents that have been RDs for 0-4 years and 40+ years. It is expected that respondents who are 45-54 years old and have been RDs for 20-29 years both slightly disagreed, as these 61 demographic categories likely overlapped with each other. However, it is unclear why this single demographic group disagreed less than the other demographic groups.

When presented with the statement “A gluten-free diet is effective for weight loss,” RDs disagreed, overall, with the statement (M = 1.83). There was a significant (p =

0.047) difference between regions. Participants from the Northeast (M = 1.74) and the

Midwest (M = 1.68) disagreed. Participants from the West disagreed less than those from the Northeast and Midwest (M = 2.04). These results are in consensus with the current research, which demonstrates that a gluten-free diet is not effective for weight loss

(Gaesser & Angadi, 2012).

Overall, RDs disagreed with the statement “The general public knows what gluten is” (M = 1.49). This statement varied significantly (p = 0.002) between age groups.

Participants that were 25-34 years old (M = 1.28) disagreed with the statement.

Respondents that were 35-44 years old (M = 1.64) and 55-64 years old (M = 1.59) disagreed less than the 25-34 year olds. Additionally, there was a significant (p = 0.002) difference depending on how many years the respondent has been an RD. Respondents that have been RDs for 0-4 years (M = 1.35), 5-9 years (M = 1.31), 20-29 years (M =

1.41), or 40+ years (M = 1.35) disagreed with the statement. Participants that have been

RDs for 30-39 years (M = 1.76) disagreed less with the statement. These results confirm the beliefs discussed in the focus groups, where participants stated that the public is unaware of what gluten is.

Generally, RDs disagreed with the statement “People following a gluten-free diet should only consume naturally gluten-free food and avoid specialty gluten-free products” 62

(M = 2.29). This statement produced several significant findings. Statistical significance existed within the categories of race (p = 0.041), region (p = 0.045), and whether or not the area of practice includes celiac disease (p = 0.018). Hispanic respondents (M = 3.29) agreed with the statement; whereas Black or African American (M = 1.67) and

Asian/Pacific Islander (M = 1.43) respondents disagreed. Respondents from the West (M

= 2.48) disagreed, however respondents from the Northeast (M = 1.74) and Midwest (M =

1.68) disagreed more. Participants whose area of practice includes celiac disease (M =

2.16) disagreed, while participants whose area of practice does not include celiac disease

(M = 2.41) disagreed less. The results of this statement were unexpected; however, it is possible that respondents felt it is more realistic for those following a gluten-free diet to incorporate specialty products into their life.

Overall, RDs agreed with the statement “The gluten-free diet is a fad (when used outside of celiac disease and nonceliac gluten sensitivity)” (M = 4.05). This statement demonstrated significant differences within age groups (p < 0.001) and whether or not the respondent was diagnosed with at least one gluten-related disorder (celiac disease,

NCGS, or wheat allergy) (p = 0.005). Individuals that were 25-34 years old (M = 4.29),

35-44 years old (M = 4.05), 55-64 years old (M = 4.18), and 65+ years old (M = 4.04) agreed with the statement. RDs that were 45-54 years old (M = 3.52) agreed less than the other age groups. RDs that have been diagnosed with at least one gluten-related disorder

(M = 3.57) agreed with the statement. RDs that have not been diagnosed with a gluten- related disorder (M = 4.09), agreed more than RDs diagnosed with a gluten-related disorder. It was expected that most RDs felt the gluten-free diet is a fad. Research has 63 shown that of the population consuming gluten-free products, only 25% were diagnosed with celiac disease (Roberts, 2016). Additionally, focus group participants stated that celebrities such as Gwyneth Paltrow may be endorsing the gluten-free diet for its alleged health benefits, thereby encouraging the general population to eat gluten-free.

When presented with the statement “People with celiac disease can consume small amounts of gluten,” overall RDs disagreed (M = 1.49). Significant differences were observed based on identifying as Hispanic or Latino (p = 0.067), race (p < 0.001), if the respondent had a gluten-related disorder (p = 0.013), and if the area of practice included celiac disease (p = 0.026). Respondents that identified as being Hispanic or Latino (M =

2.54) demonstrated disagreement with the statement. Participants that did not identify as being Hispanic or Latino (M = 1.48) demonstrated more disagreement with the statement.

Respondents identifying as White (M = 1.45) disagreed with the statement, whereas

Black or African American respondents (M = 2.83) disagreed less. RDs that have been diagnosed with a gluten-related disorder (M = 1.14) disagreed, while RDs that have not been diagnosed with a gluten-related disorder (M = 1.53) disagreed less. Respondents whose area of practice does not include celiac disease (M = 1.59) disagreed less than participants whose area of practice includes celiac disease (M = 1.39). The current guidelines state that while a completely gluten-free diet is virtually impossible due to trace amounts of gluten consumed through unintentional cross-contamination, ingestion of less than 10-20 ppm will likely not cause damage to those with celiac disease (Rubio-

Tapia, Hill, Kelly, Calderwood, & Murray, 2013). However, to protect the safety of those with celiac disease, it is recommended to avoid cross-contamination as much as possible 64

(See et al., 2015). Despite the guidelines, respondents representing populations such as

Hispanic or Latino and Black or African American had mean scores that bordered neither agree nor disagree.

The statement “Pure, uncontaminated oats are safe for people with celiac disease” revealed that most RDs agreed (M = 4.13). There were significantly different mean scores depending on race (p = 0.020) and if the participant’s area of practice included celiac disease (p = 0.020). White (M = 4.16) and Other (M = 4.10) participants demonstrated agreement with the statement. Asian/Pacific Islander respondents (M = 2.71) disagreed with the statement. Those with an area of practice including celiac disease (M = 4.25) agreed with the statement more than respondents whose area of practice did not include celiac disease (M = 4.01). The only population that did not agree to some extent with this statement was the Asian/Pacific Islander population. Research has shown that consumption of uncontaminated oats is safe for people with celiac disease (Rubio-Tapia et al., 2013).

Pertaining to the statement “Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans),” RDs agreed with the statement (M = 4.19). There was a significant difference in the mean scores for age groups (p = 0.025) and years as an RD (p = 0.014). Respondents that were

25-34 years old (M = 4.00) agreed with the statement less than respondents that were 45-

54 years old (M = 4.48). Respondents that have been RDs for 0-4 years (M = 3.91) and

40+ years (M = 3.95) agreed with the statement les than respondents that have been RDs for 20-29 years (M = 4.52). All respondents agreed with the statement to some extent. 65

This may be out of precaution to protect the safety of those that require a gluten-free diet from medical necessity. Unintentional ingestion of more than 10-20ppm of gluten by people with celiac disease can cause intestinal damage, further hindering their ability to absorb nutrients (Kelly, Bai, Liu, & Leffler, 2015; Rubio-Tapia et al., 2013).

The statement “Products that are naturally gluten-free should use a gluten-free label” was agreed with by most RDs (M = 3.30). There were significantly different results between males and females (p = 0.046). Additionally, there was a significant difference for age groups (p = 0.012) and years as an RD (p < 0.001). Males (M = 2.67) disagreed while females (M = 3.32) agreed with the statement. Respondents that were 25-34 years old (M = 3.11) agreed, while 65+ year olds (M = 2.92) disagreed. Respondents that were

45-54 years old (M = 3.64) agreed with the statement the most. Respondents that have been RDs for 0-4 years (M = 2.76) and 40+ years (M = 2.65) disagreed with the statement, while respondents that have been RDs for 5-9 years (M = 3.14), 10-19 years

(M = 3.36), 20-29 years (M = 3.69), and 30-39 years (M = 3.12) agreed with the statement. Overall, most of the means were close to the neither agree nor disagree point.

This result is expected with a topic such as gluten-free labeling. Gluten-free labeling is a topic that does not have a clear right or wrong answer. In the focus groups, several pros and cons were discussed for inclusion of a gluten-free label on products that have always been gluten-free. Focus group participants stated that a gluten-free label may be helpful for those just beginning a gluten-free diet, however it may also be a cause of confusion.

Consumers may be confused about if the product previously contained gluten and has now been reformulated. 66

Overall, RDs neither agreed nor disagreed with the statement “People following a gluten-free diet should ignore gluten-free labels and just look at the ingredient list” (M =

2.99). There were significant differences among age groups (p = 0.012), years as an RD

(p = 0.013), and if area of practice includes celiac disease (p = 0.016). Participants that were 25-34 years old (M = 3.20) agreed, while 35-45 year olds (M = 3.02) neither agreed nor disagreed. Respondents that were 65+ years old (M = 2.50) disagreed with the statement. Respondents that have been RDs for 0-4 years (M = 3.44), 5-9 years (M =

3.09), and 10-19 years (M = 3.08) agreed with the statement. Respondents that have been

RDs for 20-29 years (M = 2.84), 30-39 years (M = 2.78), and 40+ years (M = 2.40) disagreed with the statement. Participants whose area of practice includes celiac disease

(M = 2.85) disagreed, while participants whose area of practice does not include celiac disease (M = 3.12) agreed. Most of the responses in this question were close to neither agree nor disagree. Similarly to the last labeling question, there is a lot of grey area with this topic. While a gluten-free label may be helpful for some people on a gluten-free diet, it is also important to understand the specific sources of gluten (Verrill, Zhang, & Kane,

201). This is especially true since a gluten-free product is not required to use a gluten-free label. While a gluten-free label may be helpful for first identifying gluten-free options, it is always recommended to check the ingredient list (See et al., 2015).

Most RDs were in agreement with the statement “There are enough gluten-free options on the market for those following a gluten-free diet” (M = 3.62). There was statistical significance (p = 0.023) for whether or not the area of practice includes celiac disease. RDs whose area of practice includes celiac disease (M = 3.73) agreed with the 67 statement more than RDs whose area of practice does not include celiac disease (M =

3.51). Research has shown that the gluten-free market has grown substantially in recent years (Roberts, 2016). From 2013 to 2016, the gluten-free market grew by 178%. This growth indicates that there is likely a large array of options for those following a gluten- free diet.

The questions “Nonceliac gluten sensitivity is recognized as a diagnosable condition” (M = 3.32), “People with celiac disease should have regular appointments with a Registered Dietitian” (M = 3.89), and “Specialty gluten-free products are nutritionally comparable to similar gluten-containing products” (M = 2.74) did not produce any statistically significant results. These findings suggest that despite demographic differences, RDs generally were consistent in their position on these statements.

Participants were generally in agreement with the statement “Nonceliac gluten sensitivity is recognized as a diagnosable condition.” This finding is reflective of the current research on NCGS, which is controversial, but beginning to consider NCGS as a legitimate medical condition (Fasano, Sapone, Zevallos, & Schuppan, 2015). However, there are no standardized diagnostic criteria for NCGS.

Participants generally agreed with the statement “People with celiac disease should have regular appointments with a Registered Dietitian.” It is unsurprising that

RDs would tend to agree that patients with celiac disease should have regular appointments with an RD. This result is consistent with current literature, which recommends regular follow-up appointments with an RD (See et al., 2015). 68

Participants generally disagreed with the statement “Specialty gluten-free products are nutritionally comparable to similar gluten-containing products.” This result is consistent with current research, which has demonstrated that specialty gluten-free products are likely to be lower in B vitamins, iron, and fiber, and higher in sugar and fat

(Vici et al., 2016).

Relevance to Ohio. The questionnaire results were analyzed for respondents only from Ohio. There was one small difference between the results for Ohio and the national results. For the statement “People following a gluten-free diet should ignore gluten-free labels and just look at the ingredient list”, significance existed for the numbers of years the respondents have been RDs (p = 0.007). Participants that have been RDs for 0-4 years

(M = 4.00), 5-9 years (M = 4.20), and 20-29 years (M = 3.80) agreed with the statement; however respondents that have been RDs for 10-19 years (M = 2.33) and 30-39 years (M

= 2.90) disagreed with the statement. However, overall it appears that Ohio does not differ from other dietitians in the U.S. with respect to their knowledge and attitudes concerning gluten and gluten-free diets.

Conclusions

RDs are expected to be experts in the field of nutrition. However, this research has demonstrated several areas of concern for RDs and the gluten-free diet. There is a need for improved education of a gluten-free diet in the areas of sources of gluten, labeling, and gluten-related disorders among RDs.

RDs are lacking adequate knowledge about gluten’s classification as a protein.

Over 18% of respondents incorrectly identified gluten as a carbohydrate. As stated in the 69 focus groups, there is a misconception by the public that gluten is a carbohydrate. The results of this question indicate that RDs may be influenced by the media to believe that gluten is a carbohydrate. Additionally, less than 80% of RDs correctly identified the presence or absence of gluten in semolina, spelt, kamut, and buckwheat. If RDs are unable to correctly identify the presence of absence of gluten from a list of ingredients, it is difficult to assume that patients should be able to identify gluten.

Gluten-free labeling is a topic that does not have a clear right or wrong answer. In the focus groups, several pros and cons were discussed for inclusion of a gluten-free label on products that have always been gluten-free. A gluten-free label may be helpful for those just beginning a gluten-free diet, however it may also be a cause of confusion.

Consumers may be confused about if the product previously contained gluten and has now been reformulated. The questionnaire revealed that most RDs think gluten should be included on the ingredient list along with the top 8 allergens. Further research investigating the potential benefits of gluten-free labeling would be advantageous. As this is a topic with many facets, research focused specifically to labeling would be beneficial.

The majority of respondents identified celiac disease and NCGS as conditions requiring a gluten-free diet, which is supported by the current research (Elli et al., 2015;

Pietzak, 2012). However, nearly 50% selected wheat allergy. The fact that such a large portion of RDs would recommend a gluten-free diet for patients with a wheat allergy is alarming. Although a gluten-free diet is wheat-free, a wheat-free diet does not need to be gluten-free. By recommending gluten-free diet for patients with a wheat allergy, RDs are further limiting the foods that can be consumed, thereby possibly unnecessarily 70 increasing the risk of nutritional deficits. In addition, only 35.8% of respondents identified the prevalence of celiac disease as being within 0.5% of the correct estimated prevalence. This may indicate that RDs are allowing the media and other noncredible sources to influence their opinion of celiac disease, as there seems to be a misconception that the prevalence of celiac disease has significantly increased in recent years. Therefore,

RDs should receive further education about gluten-related disorders.

Research investigating various methods for educating RDs about various aspects of gluten-free diet would be of great benefit to the profession, as knowledgeable RDs are likely to provide valuable education to patient/clients on a gluten-free diet. Education in the form of continuing professional education units (CPEUs) could be a viable option for improving the knowledge of gluten and a gluten-free diet to RDs.

References

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Table 1

Categorized Summary of Results From Focus Groups on the Topic of Gluten-Free

Category

Gluten Information Protein in wheat, rye, and barley Structure and texture

Public Awareness Carbohydrate confusion Social media and celebrities

Gluten-Free Labeling Ease of use Confusion

Gluten-Free Diet Traditionally gluten-free versus specialty products Nutritional deficits

Quality Improvement, but room for growth Excess fat and sugar Increased demand

Gluten-Related Disorders Celiac Disease and NCGS Misunderstanding about prevalence

Education Gluten digestion Sources of gluten Functionality

Table 2

Statements Rated on a 5-Point Hedonic Scale, Included in Gluten-Free Questionnaire

A gluten-free diet is appropriate for the general population

Nonceliac gluten sensitivity (NCGS) is recognized as a diagnosable condition

A gluten-free diet is effective for weight loss

The general public knows what gluten is

People following a gluten-free diet should only consume naturally gluten-free food and avoid specialty gluten-free products

The gluten-free diet is a fad (when used outside of celiac disease and nonceliac gluten- sensitivity)

People with celiac disease can consume small amounts of gluten

Pure, uncontaminated oats are safe for people with celiac disease

People with celiac disease should have regular appointments with a Registered Dietitian

Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans)

Products that are naturally gluten-free should use a gluten-free label

People following a gluten-free diet should ignore gluten-free labels and just look at the ingredient list

There are enough gluten-free options on the market for those following a gluten-free diet

Specialty gluten-free products are nutritionally comparable to similar gluten- containing products

Table 3

Demographic Characteristics of Registered Dietitians Responding to a Gluten- Free Questionnaire (n = 508)

Variable n (%)

Gender Female 493 (97.0) Male 15 (3.0)

Age range (years) 25-34 147 (28.9) 35-44 131 (25.8) 45-54 94 (18.5) 55-64 110 (21.7) 65 and over 26 (5.1)

Race White 478 (94.1) Hispanic or Latino 7 (1.4) Black or African American 6 (1.2) Asian/Pacific Islander 7 (1.4) Other 10 (2.0)

Region Northeast 97 (19.1) Midwest 144 (28.4) South 174 (34.3) West 93 (18.3)

Education Doctoral degree 6 (1.2) Professional degreea 48 (9.4) Master’s degree 231 (45.5) Bachelor’s degree 223 (43.9)

Years as an RD 0-4 years 34 (6.7) 5-9 years 116 (22.8) 10-19 years 168 (33.1) 20-29 years 97 (19.1) 30-39 years 72 (14.2) 40+ years 20 (3.9) 79

Table 3: Continued Diagnosed disorder

Celiac disease 15 (29.5) Nonceliac gluten sensitivity 26 (51.2) Wheat allergy 7 (13.8)

Area of practice includes celiac disease Yes 254 (50.0) No 254 (50.0) aProfessional degree example: Pharmacist.

Table 4

Number of Registered Correctly Identifying Gluten-Containing and Gluten-Free Foods (n = 508)

Gluten- containing food n (%) Gluten-free food n (%)

Wheat 508 (100.0) Corn 502 (98.8)

Rye 448 (88.2) Brown rice 489 (96.3)

Barley 442 (87.0) Quinoa 486 (95.7)

Semolina 365 (71.9) Teff 453 (89.2)

Spelt 263 (51.8) Amaranth 448 (88.2)

Kamut 191 (37.6) Buckwheat 294 (57.9)

Table 5

Populations that Should Follow a Gluten-Free Diet as Reported by Registered Dietitians (n = 508)

Population n (%)

Celiac disease 505 (99.4)

Nonceliac gluten sensitivity 363 (71.5)

Wheat allergy 253 (49.8)

Irritable bowel syndrome 63 (12.4)

Crohn’s disease 63 (12.4)

Autism 53 (10.4)

Type 1 diabetes 20 (3.9)

Table 6

Definition of Celiac Disease as Reported by Registered Dietitians (n = 508)

Definition n (%)

Autoimmune condition 461 (90.7)

Allergy 31 (6.1)

Metabolic disease 16 (3.1)

Hormone disorder 0 (0.0)

Table 7

Appropriate Diagnostic Method for Celiac Disease as Reported by Registered Dietitians (n = 508)

Diagnostic method n (%)

Intestinal biopsy 407 (80.1)

Blood test 92 (18.1)

Oral food challenge 7 (1.4)

Skin prick test 2 (0.4)

Table 8

Percent of American Population Diagnosed with Celiac Disease as Reported by Registered Dietitians (n = 508)

Prevalence (%) n (%)

0.01 1 (0.2)

0.10 1 (0.2)

0.30 1 (0.2)

0.50 2 (0.4)

0.70 1 (0.2)

1.00 126 (24.8)

1.50 1 (0.2)

2.00 49 (9.6)

The general public knows what gluten is

People with celiac disease can consume small amounts of gluten

A gluten-free diet is appropriate for the general population

A gluten-free diet is effective for weight loss

People following a gluten-free diet should only consume naturally gluten-free food and avoid specialty gluten-free products Specialty gluten-free products are nutritionally comparable to similar gluten-containing products

People following a gluten-free diet should ignore gluten-free labels and just look at the ingredient list

Products that are naturallly gluten-free should use a gluten-free label

Non-celiac gluten sensitivity (NCGS) is recognized as a diagnosable condition

There are enough gluten-free options on the market for those following a gluten-free diet

People with celiac disease should have regular appointments with a Registered Dietitian

The gluten-free diet is a fad (when used outside of celiac disease and non-celiac gluten sensitivity)

Pure, uncontaminated oats are safe for people with celiac disease Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans)

1 2 3 4 5 Mean Score 1=Strongly disagree; 2=Slightly disagree; 3=Neigher agree nor disagree; 4=Slightly agree; 5=Strongly agree

Figure 1. Mean responses for hedonic questions on a gluten-free questionnaire from Registered Dietitians (n = 508). 83

Chapter 4: Does a Hands-On Laboratory on the Topic of Gluten-Free Baking

Increase Knowledge of Gluten in Foods?2

Abstract

The practice of gluten-free diets is on the rise, yet many people are still unaware of what gluten is and how it functions in food. As future food and nutrition professionals, it is important that students are knowledgeable in this topic. To educate students, a gluten-free focused laboratory was designed for the Science of Food II course. An important learning objective was that students were able to state the function of gluten in food. Laboratory groups created various gluten-free foods. A quantitative methods approach was used to obtain and evaluate data from students who participated in the lab.

A questionnaire was created to assess students’ knowledge of gluten prior to the laboratory. Following the laboratory, students were surveyed again to assess their new understanding of the learning objectives. Data was compared between the spring 2016 versus spring 2017 courses for improved knowledge and understanding in this topic.

There was no improvement in the reported knowledge of gluten following either laboratory activity. The laboratory activities utilized in this study were ineffective for improving undergraduate students’ knowledge of gluten.

2 This chapter has been formatted as a manuscript to submit for publication to the Journal of Food Science Education. Authors are Hannah Johnson (School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens, OH), with Elizabeth Beverly (Assistant Professor, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH), Deborah Murray, MS, RD, (Associate Lecturer, School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens, OH, and Robert Brannan, PhD (Associate Professor, School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens, OH). 84

Keywords: Education, learning, gluten-free, laboratory, activity

Introduction

Gluten is a protein that contains prolamin and glutelin components. Gluten is frequently referred to as being found in wheat, rye, and barley (Gessendorfer, Koehler, &

Wieser, 2009). However, gluten technically only exists in the endosperm of wheat (Ryan,

2015; Veloso, Dias, Rodrigues, & Peres, 2016). Additionally, the combination of flour and water produces gluten by food science standards (Day, Augustin, Batey, & Wrigley,

2006). Properties including structural stability and viscoelasticity are frequently associated with gluten-containing products.

It is common for gluten-free products to have evident quality deficits in comparison to gluten-containing products (Zannini, Jones, Renzetti, & Arendt, 2012). A collective agreement among the existing research regarding gluten-free products is that it is challenging to reach similar products when using gluten-free ingredients as a replacement for gluten-containing food. Crumbliness and a lack of structural stability are frequently observed in gluten-free products. Overall, while it is a possibility to create consumer-accepted gluten-free products, consumers often favor the gluten-containing control product.

The reported retail sales and use of gluten-free products has increased rapidly in the past few years (Roberts, 2016). A 2016 report found that only 25% of the population consuming gluten-free products has been diagnosed with celiac disease. Individuals with celiac disease elicit a negative immunological reaction subsequent to gluten consumption

(Green, Lebwohl, & Greywoode, 2015). Therefore, a gluten-free diet is the recommended 85 treatment for celiac disease. A recent study utilizing National Health and Nutrition

Examination Surveys (NHANES) results determined that 1.69% of people over 6 years old with no diagnosis of celiac disease are on a gluten-free diet (Kim et al., 2016).

A crucial issue for those following a gluten-free diet out of medical necessity is knowledge of gluten-containing foods. Identifying gluten-containing ingredients involves more than searching for the words wheat, rye, or barley on a product’s ingredient list.

Lesser-known ingredients that contain gluten include bulgur, einkorn, kamut, semolina, and triticale (Case, 2005). Accidental ingestion of gluten is possible when individuals are unaware of these less commonly known ingredients (Silvester, Weiten, Graff, Walker, &

Duerksen, 2016). Gluten-free labeling regulations were established in 2013 by the U.S.

Food and Drug Administration (2013). The regulations state that for a product to include the words “gluten-free,” “free of gluten,” “without gluten,” or “no gluten,” it has to contain possess under 20 parts per million (ppm) of gluten.

To provide ideal education for patients on a medically required gluten-free diet,

Registered Dietitians (RDs) should be knowledgeable about a gluten-free diet (Case,

2005; See, Kaukinen, Makharia, Gibson, & Murray, 2015). It is important for patients to be educated on topics such as gluten-containing foods, label reading, dining out, and cross-contact.

Hands-on approaches to learning are useful for reinforcing information taught in traditional lectures, particularly in science courses. A recent study found that in an undergraduate Food Science course, project-based learning involving a laboratory aspect resulted in “positive learning outcomes” (Lee, 2015). In Food Science laboratory courses, 86 students typically work in groups. Each group will prepare a different variation of an assigned recipe. The completed products are analyzed using appropriate quantitative methods and sensory evaluations. Students benefit from laboratory-based coursework by gaining hands-on experience with the sensory differences in variations of recipes. Group work allows students to collaborate in a way that is impractical in the traditional lecture setting. Working together in groups creates an environment that is conducive for gaining new insights into the educational material.

In a companion paper wherein we report the findings of a mixed methods survey of more than 500 RD’s from across the United States on the topic of gluten, we learned that 18% of RD’s misidentified gluten as a carbohydrate. Thus, the objective of this research is to evaluate the impact of a hands-on gluten-free laboratory activity on the knowledge of gluten and gluten-free foods by undergraduate nutrition students.

Materials and Methods

All studies involving human subjects were approved by Ohio University’s

Institutional Review Board.

Questionnaire. A two-group pretest-posttest design was employed. Students were recruited from Ohio University’s NUTR 2220 (Science of Food II) course and asked to complete a prelaboratory questionnaire evaluating knowledge of gluten-free food (see

Appendix F). Students provided consent without signature before completing the questionnaire (see Appendix G). The questionnaire utilized questions existing in a questionnaire developed by Quinteros-Fernandez (2015). The questionnaire was disseminated using an online data collection and analysis software system (Qualtrics, 87

2015). Students were provided with iPads to complete the questionnaire; however, they were also permitted to use their personal cell phones.

Immediately after completing the questionnaire, students participated in a hands- on laboratory activity on gluten-free baking. Participation in the laboratory and submission of the study questions were required of the students regardless of whether they voluntarily participated in the questionnaire. Two weeks following the completion of the laboratory, students again were recruited to participate in the questionnaire (the posttest), which was identical to the pretest questionnaire. Because participation in the pretest and posttest was voluntary, not all students participated in both questionnaires.

The laboratory activities from 2016 and 2017 were similar, but not identical. In

2016, students compared gluten-free pancakes and cakes prepared from commercial gluten-free baking mixes to full-gluten pancakes and cakes prepared from all-purpose flour. In 2017, cakes were prepared from different gluten-free ingredients formulated to replace all-purpose flour and compared to a cake made from an acceptable commercially available gluten-free baking mix.

The full laboratory procedures for the 2016 lab are shown in Appendix H.

Students worked in pairs to prepare two recipes, one for cake and one for pancakes, and were assigned recipe variations using all-purpose flour or a gluten-free substitution using

Domata Gluten-Free Recipe Ready Flour, Cup4Cup Original Multi-Purpose Flour, Bob’s

Red Mill 1-to-1 Gluten-Free Baking Flour, or Bob’s Red Mill Gluten-Free All Purpose

Baking Flour. Students assessed each variation of pancake and cake subjectively based 88 on appearance, flavor, and texture, and objectively for height (mm) using a ruler and hardness (mm) using a penetrometer.

The full laboratory procedures for the 2017 lab are shown in Appendix I. Students worked in pairs to prepare a cake recipe and were assigned recipe variations using all- purpose flour or a gluten-free alternative (see Table 1). Students assessed each variation of cake subjectively based on appearance, flavor, and texture, and objectively for height

(mm) using a ruler and hardness (mm) using a penetrometer

Data analysis. Data collected from the pre- and postlaboratory questionnaires was analyzed to determine how frequently participants correctly answered questions. A comparison was made between the pre- and postquestionnaire results to determine if the laboratory was effective in improving student’s knowledge of gluten.

The prelaboratory questionnaire results from 2016 and 2017 were analyzed for possible significance using a t-test. An analysis of variance was used to examine potential significance based on whether or not students reported using the Ohio University Dining

Halls.

Results and Discussion

In a companion paper, focus groups including nutrition students and RDs as participants were conducted on the topic of the gluten-free diet. Results from the focus groups were used to assist in the development of the laboratory activity described in this paper. Suggestions from the focus group participants included utilizing various gluten- free substitutes to understand their different functionalities. Therefore, multiple gluten- free mixes were used to make both pancakes and cakes. 89

Demographics. The demographics skewed heavily female (< 90%), white (<

90%), and young (< 24) (see Table 2). One area that was of interest was whether students had used Ohio University Dining halls (38-60% of students), but this distinction did not affect the correct identification of gluten in foods. When comparing the ability of students who did or did not use the Ohio University Dining Halls to identify gluten in foods, there was no statistically significant difference between pretest scores (p = 0.766 in 2016; p =

0.274 in 2017) or posttest scores (p = 0.061 in 2016; p = 0.976 in 2017). Therefore, students who used the dining halls did not score significantly different from students who did not use the dining halls.

Laboratory. There was no significant improvement (p = 0.318) in students’ ability to correctly identify the presence or absence of gluten from the 2016 prelaboratory questionnaire to the 2016 postlaboratory questionnaire (see Figures 1-2). Students pretested in 2016 were able to identify correctly the presence or absence of gluten in food products 65% of the time. Students posttested in 2016 were able to identify correctly the presence or absence of gluten in food products 66% of the time.

The 2016 laboratory exercises employed the use of commercial gluten-free baking mixes for the purpose of demonstrating to the students that different mixes may create cakes and pancakes with different characteristics. Following employment of the 2016 laboratory, modifications were made for the 2017 laboratory activity. The use of premade commercial mixes may have been ineffective due to the lack of exposure to specific gluten-free flours. The concept of using individual flours instead of commercial mixes was thought to be a more effective method for teaching about gluten-free baking because 90 using individual gluten-free flours instead of commercial mixes would expose students to the specific characteristics of each type of flour. The changes were made in hopes of improving the students’ knowledge of the presence or absence of gluten in foods.

In spite of these changes, there was no significant improvement (p = 0.566) in students’ ability to correctly identify the presence or absence of gluten from the 2017 prelaboratory questionnaire to the 2017 postlaboratory questionnaire (see Figures 3 and

4). Students pretested in 2017 were able to identify correctly the presence or absence of gluten in food products 68% of the time. Students post tested in 2017 were able to identify correctly the presence or absence of gluten in food products 67% of the time.

The lack of knowledge gain during the 2017 laboratory activity may be due to the limited use of gluten-free flours in cakes. Using the flours not only in cakes, but also in products such as sauces, puff pastries, and crepes may be beneficial in improving the knowledge gained during a laboratory activity. The utilization of gluten-free flours in products other than baked goods may improve the knowledge gained from a laboratory activity.

An interesting finding concerns the relationship between the students’ ability to identify gluten in gluten-containing foods versus their ability to identify the absence of gluten in gluten-free foods. Students were able to identify the absence of gluten in gluten- free foods at a significantly higher level than the presence of gluten in gluten-containing foods (p = 0.003 in 2016 pretest; p = 0.002 in 2016 posttest; p = 0.007 in 2017 pretest; p

= 0.006 in 2017 posttest). Students correctly identified the absence of gluten in gluten- free foods 73.4% of the time in the 2016 prelaboratory questionnaire and 77.2% of the 91 time in the 2016 postlaboratory questionnaire. Students correctly identified the presence of gluten in gluten-containing foods 56.2% of the time in the 2016 prelaboratory questionnaire and 54.2% of the time in the 2016 postlaboratory questionnaire. Results from the 2017 questionnaire were similar to 2016. Students correctly identified the absence of gluten in gluten-free foods 77.3% of the time in the 2017 prelaboratory questionnaire and 78.5% of the time in the 2017 postlaboratory questionnaire. Students correctly identified the presence of gluten in gluten-containing foods 59.3% of the time in the 2017 prelaboratory questionnaire and 56% of the time in the 2017 postlaboratory questionnaire. This finding suggests that regardless of the laboratory activity, students were consistently more knowledgeable about gluten-free products versus gluten- containing products.

Ohio University Dining Halls offer information online and in the Dining Halls for special diets, including gluten-free. Ohio University Dining Halls have an RD dedicated to providing assistance for special diets. Of students who participated in the questionnaire, 48% use the dining halls, so it could be hypothesized that they had more knowledge of gluten and gluten-free products than participants who did not. In the 2016 and 2017 prelaboratory questionnaire, students who used the dining halls correctly identified the absence of gluten in gluten-free foods significantly more than they identified the presence of gluten in gluten-containing foods (p = 0.013 in 2016; p = 0.009 in 2017). Students who did not use the dining halls correctly identified the absence of gluten in gluten-free foods significantly more in the 2017 prelaboratory questionnaire (p

= 0.002), but not in the 2016 prelaboratory questionnaire (p = 0.100 in 2016). The result 92 that students can correctly identify the absence of gluten in a larger percentage of gluten- free foods than the presence of gluten in gluten-containing foods suggests that students using the Ohio University Dining Halls had more exposure to gluten-free foods and therefore a higher knowledge base prior to participating in the questionnaire.

The prelaboratory and postlaboratory questionnaires produced similar results for both 2016 and 2017. Students pretested in 2016 and 2017 were able to identify correctly the presence or absence of gluten in 65% and 68% of food products, respectively.

Statistical analysis revealed no significant difference (p = 0.092) between the mean prelaboratory questionnaire scores for 2016 and 2017. Students post tested in 2016 and

2017 were able to identify correctly the presence or absence of gluten in 66% and 67% of food products, respectively. Statistical analysis revealed no significant difference (p =

0.531) between the mean postlaboratory questionnaire scores for 2016 and 2017.

Additionally, the 2016 and 2017 prelaboratory questionnaires were combined and analyzed against the 2016 and 2017 postlaboratory questionnaires. However, there was no significant difference (p = 0.772) between them. This result is unsurprising, because demographic characteristics of participants were similar between 2016 and 2017.

There was no substantial improvement in the reported knowledge of gluten following either laboratory activity. Therefore, the laboratory activities utilized in this study were ineffective for improving undergraduate students’ knowledge of gluten. The lack of knowledge gain may be due to the types of food made during the laboratories.

Perhaps making other items such as brownies, muffins, or puff pastries, or nonbaked goods including sauces or crepes, would have been more effective for educating students. 93

Additionally, integrating information about gluten-related disorders, as was suggested in the focus groups, may have assisted in the retention of knowledge during the laboratory.

Conclusions

Regardless of the laboratory activity, students were consistently able to identify the absence of gluten in gluten-free foods more frequently than they were able to identify the presence of gluten in gluten-containing foods. A laboratory activity focused on gluten-containing products rather than gluten-free products may be beneficial for educating students about gluten.

Future research should alter the prelaboratory and postlaboratory survey methods.

Additionally, utilizing a different laboratory activity may be beneficial for increasing student knowledge. A laboratory activity incorporating nutritional differences in gluten- free versus gluten-containing products may be advantageous. Furthermore, a laboratory activity that integrates information about gluten-related disorders may encourage students to retain the information more effectively.

A questionnaire including questions about the function of gluten may be useful in future studies. A questionnaire that solely assesses students’ ability to identify the presence or absence of gluten in food products may not fully evaluate knowledge gained during a laboratory activity. Inclusion of questions on gluten’s function in food products, as well as characteristics of gluten-free food products may be beneficial in future research.

Incorporation of nutritional information rather than just food science information may improve the knowledge gained during a laboratory activity on the topic of gluten- 94 free. Because the participants were undergraduate nutrition students, they probably have an interest in the nutritional aspect of the topic. Therefore, inclusion of information such as nutritional differences between gluten-free and gluten-contain products may be useful for increasing knowledge gain following completion of the laboratory activity.

A laboratory activity that includes information about gluten-related disorders may encourage students to retain the information about gluten-free food more effectively.

Assuming most of the students in the laboratory will go on to become RDs, it is likely that they have some level of interest in human nutrition. Therefore, incorporation of information on gluten-related disorders, such as celiac disease and nonceliac gluten sensitivity, may help to increase their engagement in the laboratory activity; thereby, increasing their knowledge gained following completion of the laboratory activity.

A limitation of this study is the small sample size. Further, the sample size decreased in both years from the prelaboratory questionnaire to the post-laboratory questionnaire. This decrease in respondents likely had an impact on the accuracy of the results.

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Table 9

Recipe Variations

Variation Ingredients Amount

1 Brown rice flour 1 cup Potato starch ¼ cup Xanthan gum ¼ cup

2 Brown rice flour ½ cup Oat flour ½ cup Potato starch ¼ cup Xanthan gum ¼ cup

3 Oat flour 1 cup Potato starch ¼ cup Xanthan gum ¼ cup

4 Soy flour ½ cup Brown rice flour ½ cup Potato starch ¼ cup Xanthan gum ¼ cup

5 Soy flour 1 cup Tapioca starch ¼ cup Xanthan gum 2 T

6 King Arthur multipurpose gluten- 1 ½ cups free flour

Table 10

Demographics of Respondents

2016 2017

Pre- Post- Pre- Post- Variable (n = 55) (n = 45) (n = 48) (n = 34)

Age Range 18-24 54 45 47 33 25-34 1 0 1 1

Sex Male 7 5 4 2 Female 48 40 44 32

Race/Ethnicity Caucasian/White 47 39 43 31 Hispanic or Latino 2 1 1 1 Black or African American 3 4 1 0 Asian/Pacific Islander 2 0 2 1 Native American 1 1 0 0 Other 0 0 1 1

Use Ohio University Dining Hall Yes 32 27 18 10 No 23 18 30 23

White flour Pastas, breads, muffins, cakes Cookies and crackers Whole wheat flour Beer/Malt Wheat bran Cold cereals Barley Durum wheat Wheat germ Triticale Rye Dressings, gravies, sauces Graham flour Semolina Post-survey Soy sauce Pre-survey Couscous Bulgur Kamut Spelt 0 20 40 60 80 100 Correct Responses (%)

Figure 2. 2016 Correct responses for gluten-containing products.

100

Amaranth Teff Guar gum Seeds and nuts Xanthan gum Sweet rice Quinoa Almond flour Beans and lentils Tapioca starch Buckwheat Modified food starch Corn/Corn starch Post-survey Corn flour/Cornmeal Pre-survey Potato flour Potato starch Soy flour Brown rice Oats 0 20 40 60 80 100 Correct Responses (%)

Figure 3. 2016 Correct responses for gluten-free products.

101

White flour Pastas, breads, muffins, cakes Cookies and crackers Whole wheat flour Beer/Malt Wheat bran Cold cereals Barley Durum wheat Wheat germ Triticale Rye Dressings, gravies, sauces Post-survey Graham flour Pre-survey Semolina Soy sauce Couscous Bulgur Kamut Spelt 0 20 40 60 80 100 Correct Responses (%)

Figure 4. 2017 Correct responses for gluten-containing products. 102

Amaranth Teff Guar gum Seeds and nuts Xanthan gum Sweet rice Quinoa Almond flour Beans and lentils Tapioca starch Buckwheat Modified food starch Corn/Corn starch Corn flour/Cornmeal Potato flour Potato starch Soy flour Brown rice Oats 0 20 40 60 80 100 Correct Responses (%)

Figure 5. 2017 Correct responses for gluten-free products.

103

Chapter 5: Discussion

The results of this research demonstrated that there is a need for further education of gluten and the gluten-free diet for future and current RDs. RDs are lacking adequate knowledge about gluten’s classification as a protein. The high number of RDs that incorrectly identified gluten as a carbohydrate suggests a need for improved education on even the most basic aspects of a gluten-free diet. Additionally, students consistently identified the presence or absence of gluten from a list of food products less than 70% of the time. Research has demonstrated that patients who receive inadequate education about the gluten-free diet are less likely to abide by the diet and have higher health care expenses (See et al., 2015). Therefore, research investigating effective methods for educating nutrition students and RDs would be beneficial to both the profession and individuals on a gluten-free diet.

It is important that RDs are knowledgeable about appropriate uses for a gluten- free diet. Regarding perceptions of a gluten-free diet, participants reported that a gluten- free diet is not appropriate for the general public or weight loss and the gluten-free diet is a fad when used outside of celiac disease and nonceliac gluten sensitivity. The majority of respondents identified celiac disease and NCGS as conditions that would benefit from a gluten-free diet, a claim supported by current research (Elli, Roncoroni, et al., 2015;

Pietzak, 2012). However, many participants also identified conditions that have very little scientific evidence to support the use of a gluten-free diet. In fact, nearly 50% selected wheat allergy; over 12% selected irritable bowel syndrome and Crohn’s disease; over

10% selected autism; and, almost 4% selected type 1 diabetes. In addition, only 35.8% of 104 respondents were within 0.5% of the estimated prevalence of celiac disease. The recommendation of a gluten-free diet for wheat allergy by such a large group of RDs is concerning. While a gluten-free diet is wheat-free, a wheat-free diet does not have to be gluten-free. Unnecessarily recommending a gluten-free diet will probably limit the amount of foods that can be consumed, thereby potentially leading to nutritional deficits.

Therefore, RDs should receive further education about appropriate uses for a gluten-free diet.

Consumers may be confused about if the product previously contained gluten and has now been reformulated. The questionnaire revealed that most RDs think gluten should be included on the ingredient list along with the top eight allergens. Further research investigating the potential benefits of gluten-free labeling would be advantageous. As this is a topic with many facets, research focused specifically on labeling would be beneficial.

Additionally, research investigating various methods for educating RDs about a gluten- free diet would be of great benefit to the profession.

105

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127

Appendix A: Literature on Gluten-Free Products

Table 11

Literature on Gluten-Free Products

Product Category Product Variable Results Reference The control product, wheat biscuits, received the highest overall acceptability for the sensory Buckwheat evaluation. The (Kaur et al., Biscuits Gums biscuits buckwheat biscuits 2015) with xanthan gum received the next highest score, which was significantly lower than the control.

The ratio of 60% (de la Barca, popped amaranth flour Rojas-Martínez, Popped and raw Bread Amaranth bread to 40% raw amaranth Islas-Rubio, & amaranth flour flour produced the Cabrera-Chávez, optimal bread. 2010)

Bread made from chickpea flour demonstrated the best Legume flour (Miñarro et al., Bread Chickpea flour rheological bread 2012) characteristics and adequate sensory characteristics.

Rice bran protein (Phongthai, Rice bran protein concentrate is an D’Amico, Bread Rice flour bread concentrate effective substitute in Schoenlechner, & gluten-free bread. Rawdkuen, 2016)

Up to 25% quinoa flour and a Rice flour, potato replacement for starch, and buckwheat flour was (Turkut et al., Bread Quinoa flour buckwheat flour successfully 2016) bread incorporated into a commercial gluten-free bread formulation. 128

Table 11: Continued

Addition of up to 1.25% ovalbumin in (Nozawa, Ito, & Bread Rice flour bread Ovalbumin rice bread resulted in a Arai, 2016) softer crust.

Bread formulated with (Pacynski, Corn starch and the aroma precursors Wojtasiak, & Bread gluten-free wheat Proline and glucose proline/glucose Mildner- starch bread improved the aroma. Szkudlarz, 2015)

All bread variations Rice flour and made with quinoa flour Quinoa and (Alencar et al., Bread potato starch were significantly amaranth flour 2015) bread more bitter compared to the control.

Addition of any amount of ITFs (4, 8, 10, and 12%) resulted Rice flour and Prebiotic inulin- in bread with (Capriles & Bread potato starch type fructans significantly improved Arêas, 2013) bread (IFTs) appearance, color, texture, and overall acceptability by sensory evaluation.

After the elimination of shortening, bread containing both (Aguilar, Tiger nut and chickpea and tiger nut Albanell, Bread Corn starch bread chickpea flour flour retained specific Miñarro, & volume, bake loss, Capellas, 2015) crumb hardness, crumb color, and crust color.

Replacement of pectin and guar gum with 1.8% and 2.4% linseed (Korus, Witczak, Corn and potato Bread Linseed mucilage mucilage resulted in Ziobro, & starch bread improved sensory Juszczak, 2015) acceptance compared to the control.

129

Table 11: Continued

Addition of 30g/kg (Mohammadi, guar gum and 1 unit/g Rice flour, soy Guar gum and Azizi, Neyestani, pro TGase resulted in Bread flour, and corn transglutaminase Hosseini, & the best bread in terms starch bread (TGase) Mortazavian, of sensory evaluation 2015) and crumb hardness.

Firmness and chewiness significantly decreased, while cohesiveness, (Onyango, springiness, and Mutungi, Bread Sorghum bread Cassava starch resilience significantly Unbehend, & increased with Lindhauer, 2011) increasing concentrations of cassava.

None of the gluten-free bread varieties were able to recreate every (Hager et al., Bread Wheat bread Oat flour physical property of 2012) wheat bread; however, the oat bread was the most similar.

Soluble fiber (Nutriose and polydextrose) increased the specific Rice flour and volume and decreased (Martínez, Díaz, Bread Soluble fiber corn starch bread the hardness and & Gómez, 2014) cohesiveness of the bread, compared to the control.

Supplementation of 6% MFAX and 105% water absorption (Ayala-Soto, Maize fiber Rice flour, yeast- resulted in significantly Serna-Saldívar, & Bread arabinoxylans leavened bread higher moisture Welti-Chanes, (MFAX) content and specific 2017) volume compared to the control.

130

Table 11: Continued

Variations F3 (15g xanthan gum) and F10 (10g xanthan gum and (Mohammadi, Xanthan gum and 10g carboxymethyl Sadeghnia, Azizi, Rice flour Bread carboxymethyl cellulose) retained their Neyestani, & flatbread cellulose moisture and elasticity Mortazavian, the longest and were 2014) highly accepted in the sensory evaluation.

Lactobacillus plantarum FST 1.7 demonstrated antifungal properties when incorporated in gluten-free sourdough. Rice flour, corn In addition, bread starch, Lactobacillus utilizing lactobacillus (Moore et al., Bread buckwheat flour, plantarum FST 1.7 plantarum FST 1.7 was 2008) and soya flour significantly softer sourdough after five days, compared to the nonacidified control bread and the chemically acidified bread.

Addition of 10 U/g of TGase to buckwheat flour bread and brown rice flour bread batter Buckwheat flour Microbial (Stefano Renzetti, resulted in significantly Bread bread and brown transglutaminase Dal Bello, & improved baking loss, rice flour bread (TGase) Arendt, 2008) specific volume, crumb hardness, and crumb chewiness compared to bread without TGase.

131

Table 11: Continued

Bread made from unfermented frozen dough had a (Mezaize, significantly lower Chevallier, Le- Rice flour and Bread Freezing specific volume and Bail, & de corn starch bread harder crumb than Lamballerie, bread made from 2010) conventional, unfrozen gluten-free dough.

Addition of chestnut (Rinaldi, Paciulli, Chestnut flour and flour and/or sourdough Corn flour and Caligiani, Bread fermented resulted in significantly rice bread Scazzina, & sourdough softer crust after 5 Chiavaro, 2017) days.

Replacement of 20% of rice flour with an Rice flour layer oat fiber-inulin mixture (Gularte, de la Cake cake Oat fiber and inulin resulted in an Hera, Gómez, & acceptable product Rosell, 2012) with added nutritional benefit.

Cakes made with 0.3% and 0.4% xanthan gum Rice and corn (Preichardt et al., Cake Xanthan gum were acceptable in flour cake 2011) both sensory and physical measures

Enrichment of up to 30% lupin flour or 10% buckwheat flour in gluten-free cake was Rice flour and Lupin or (Levent & Cake statistically similar in corn starch cake buckwheat flour Bilgiçli, 2011) overall acceptance by sensory panelists, compared to the control cake.

132

Table 11: Continued

The addition of soy flour to gluten-free layer cakes did not significantly alter the Soy flour and specific volume. Soy corn starch layer flour enrichment at any (Dhen et al., Cake Soy flour cake and sponge particle size and/or 2016) cake percentage significantly changed the hardness of both layer cake and sponge cake.

Sorghum flour heated to 125°C for 30 minutes produced cake with significantly (Marston, Sorghum flour higher overall Cake Heat treatment Khouryieh, & cake acceptability by the Aramouni, 2016) consumer panelists, compared to the control, non-heat treated sorghum flour.

Rice flour cupcakes made with particle size distributions of < 125, Rice flour with < 95, and < 75 µm had Rice flour (Kim & Shin, Cake varying particle significantly higher cupcakes 2014) size distributions sensory acceptance than muffins with particle size distribution < 180 µm.

133

Table 11: Continued

Cookies made with fine-grained short- grain rice and fine- grained precooked maize had statistically Fine-grained short- similar consumer Sugar-snap grain rice and fine- (Mancebo et al., Cookies acceptability compared cookies grained precooked 2015) to cookies made with maize flour wheat. Every cookie variation resulted in a significantly different spread factor compared to the wheat cookie.

In nearly every sensory property evaluation, packed rice-buckwheat cookies stored at ambient temperature Rice and Packed at ambient maintained statistically (Sakač et al., Cookies buckwheat flour temperature unchanged scored for 2016) cookies the longest period of time, compared to unpacked and/or elevated storage temperature.

Addition of any amount of oat bran to oat flour cookies (Duta & Culetu, Cookies Oat flour cookies Oat bran resulted in significantly 2015) lower sensory acceptability.

Water chestnut flour- based cookies substituted with (Sarabhai & Water chestnut Wheat protein Cookies 10g/100g of whey Prabhasankar, flour cookies isolate protein isolate 2015) produced the best sensory properties.

134

Table 11: Continued

The germinated and raw chenopodium cookies were statistically similar to the wheat cookies in Germinated and Chenopodium overall sensory (Jan, Saxena, & Cookies raw chenopodium flour cookies acceptability. Hardness Singh, 2016) flour of the germinated and raw chenopodium cookies was significantly lower than the wheat cookies.

All variations of cookies made with (Mancebo, Rice flour Maize starch and 20% pea protein were Cookies Rodriguez, & cookies pea protein significantly softer Gómez, 2016) than the 100% rice flour cookies.

Amaranth cookies with and without oat composites were significantly harder than the wheat cookies. Amaranth sugar Overall sensory (Inglett et al., Cookies Oat composites cookies acceptability was 2015) similar among amaranth cookies with and without oat composites compared to wheat cookies.

The whole grain buckwheat crackers were statistically Whole grain and Buckwheat similar to both the (Sedej et al., Crackers refined grain crackers refined and whole 2011) buckwheat flour grain wheat crackers in all measured sensory parameters.

135

Table 11: Continued

Chickpea flour, green lentil flour, Red lentil flour, Pea protein isolate and pinto bean flour, pea fibre isolate (Han, Janz, & Crackers Pulse crackers navy bean flour, crackers ranked highest Gerlat, 2010) yellow pea flour, in overall acceptability pea protein isolate, by sensory evaluation. and pea fibre isolate

Pea protein isolate muffins statistically Rice flour (Matos et al., Muffins Pea protein isolate similar to vital wheat muffins 2014) gluten muffins in all textural parameters

Replacement of wheat flour with barnyard millet flour in muffins resulted in significant changes in the textural, Barnyard millet physical, and sensory (Goswami et al., Muffins Wheat muffins flour characteristics. Despite 2015) this, the 100% BMF muffins were within the acceptable range for the sensory evaluation.

Addition of at least 8g/100g of either white cowpea protein isolate or red cowpea protein (Shevkani, Kaur, Cowpea protein Muffins Rice muffins isolate to rice muffins Kumar, & Singh, isolate increased the firmness, 2015) springiness, cohesiveness, and chewiness.

Muffins made with egg yolk granules were Corn flour (Marcet, Paredes, Muffins Egg yolk granules significantly harder muffins & Díaz, 2015) than muffins made with whole egg yolk.

136

Table 11: Continued

The best pasta (Larrosa, contained 6.6 g/100 g Lorenzo, Pasta Corn starch pasta Egg protein egg protein mix and Zaritzky, & 35.96 g/100 g water. Califano, 2016)

Pasta containing 40g/100g corn meal (da Silva, Corn meal and Pasta Pasta and 60g/100g brown Ascheri, & brown rice rice produced the best Ascheri, 2016) textural properties.

Incorporation of hydrothermally treated Hydrothermally glutinous rice and treated xanthan gum polysaccharide significantly increased Pasta Rice pasta (Cai et al., 2016) mixtures of the extensibility, while glutinous rice flour decreasing the and xanthan gum firmness, stickiness, and chewiness of rice pasta.

Pasta dough made with 5% and 7.5% inulin (Mastromatteo, demonstrated higher Iannetti, Civica, Pasta Maize spaghetti Inulin elongation and shear Sepielli, & Del viscosity compared to Nobile, 2012) the control with 0% inulin.

Gluten-free fresh filled pasta supplemented with xanthan gum (Sanguinetti et Pasta Fresh filled pasta Xanthan gum maintained moisture al., 2015) better than pasta with guar gum.

Replacement of a portion of rice flour with bean flour in (Giuberti, Gallo, spaghetti resulted in Rice flour Cerioli, Fortunati, Pasta Bean flour significantly altered spaghetti & Masoero, color, as well as 2015) increased optimal cooking time and water absorption. 137

Table 11: Continued

Rice pasta enriched with 10-30g/100g of yellow pea, chickpea, and/or lentil flour had (Bouasla et al., Pasta Rice spaghetti Legume flour statistically unchanged 2017) overall sensory acceptability compared to the control rice pasta.

A combination of Sorghum and sorghum flour, rice (Ferreira et al., Pasta potato starch Rice flour flour, and potato starch 2016) spaghetti creates an acceptable gluten-free pasta

Spaghetti made with a Dried potato pulp ratio of 65:10:25 for Amaranth and (DPP), extruded DPP, EPP, and AF, (Bastosa et al., Pasta potato pulp potato pulp (EPP), respectively, was 2016) spaghetti and amaranth flour highly accepted by (AF) sensory evaluation.

The pasta made with 35.5% water, 4.7% (Larrosa, protein, and 2.5% Corn flour and Water, egg protein, Lorenzo, Pasta gums demonstrated the corn starch pasta and gums Zaritzky, & highest storage Califano, 2013) modulus, breaking force, and extensibility.

Dough made with higher gum content Gums (xanthan and and lower W, WPC, guar gum), water and E content (Lorenzo, Corn and cassava (W), whey protein demonstrated the Pie crust Zaritzkya, & starch pie crust concentrate overall highest Califano, 2008) (WPC), and dry puncture force, egg (E) elongation force, and deformation at breaking results.

138

Appendix B: Focus Group Signed Consent Form

139

140

Appendix C: Focus Group Outline

141

Appendix D: RD Questionnaire

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144

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147

148

149

150

151

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Appendix E: RD Consent Form

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154

Appendix F: Supplemental Material to be Submitted to the Journal of the Academy

of Nutrition and Dietetics

Table 12

Percent of American Population Diagnosed with Celiac Disease as Reported by Registered Dietitians (n = 508)

Prevalence (%) n (%)

0.01 1 (0.2)

0.1 1 (0.2)

0.3 1 (0.2)

0.5 2 (0.4)

0.7 1 (0.2)

1.0 126 (24.8)

1.5 1 (0.2)

2.0 49 (9.6)

2.5 1 (0.2)

3.0 45 (8.9)

4.0 5 (1.0)

5.0 85 (16.7)

6.0 2 (0.4)

7.0 6 (1.2)

8.0 9 (1.8)

10 72 (14.2)

12.0 2 (0.4)

13.0 1 (0.2)

14.0 1 (0.2) 155

Table 12: Continued

15.0 24 (4.7)

20.0 19 (3.7)

25.0 17 (3.3)

30.0 10 (2.0)

33.0 1 (0.2)

35.0 2 (0.4)

38.0 1 (0.2)

40.0 3 (0.6)

45.0 1 (0.2)

50.0 1 (0.2)

70.0 1 (0.2)

156

Table 13

Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as Reported by Registered Dietitians, Based on Gendera (n = 508)

Mean score

Male (n = Female (n Question 15) = 493) P value

A gluten-free diet is appropriate for the general population 1.47 1.56 0.693

Non-celiac gluten sensitivity (NCGS) is recognized as a diagnosable condition 3.20 3.33 0.664

A gluten-free diet is effective for weight loss 1.33 1.84 0.282

The general public knows what gluten is 1.53 1.49 0.825

People following a gluten-free diet should only consume naturally gluten-free food and avoid specialty gluten-free products 1.87 2.30 0.179

The gluten-free diet is a fad (when used outside of celiac disease and non-celiac gluten sensitivity) 4.13 4.04 0.775

People with celiac disease can consume small amounts of gluten 1.67 1.49 0.491

Pure, uncontaminated oats are safe for people with celiac disease 4.60 4.12 0.118

People with celiac disease should have regular appointments with a Registered Dietitian 3.87 3.89 0.939

Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans) 4.07 4.19 0.661

Products that are naturally gluten-free should use a gluten-free label 2.67 3.32 0.046

People following a gluten-free diet should ignore gluten-free labels and just look at the ingredient list 3.40 2.97 0.187

There are enough gluten-free options on the market for those following a gluten-free diet 3.20 3.63 0.130 157

Table 13: Continued

Specialty gluten-free products are nutritionally comparable to similar gluten-containing products 2.80 2.74 0.828 a1=Strongly disagree, 2=Slightly disagree, 3=Neither agree nor disagree, 4=Slightly agree, 5=Strongly agree

158

Table 14

Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as Reported by Registered Dietitians, Based on Age Groupsa (n = 508)

Mean score

25-34 (n 35-44 (n 45-54 (n 55-64 (n 65+ (n Question = 147) = 131) = 94) = 110) = 26) P value

A gluten-free diet is appropriate for the general population 1.42B 1.56A,B 1.87A 1.45B 1.62A,B 0.003

Non-celiac gluten sensitivity (NCGS) is recognized as a diagnosable condition 3.32 3.17 3.34 3.51 3.31 0.241

A gluten-free diet is effective for weight loss 1.79 1.89 1.99 1.71 1.65 0.285

The general public knows what gluten is 1.28B 1.64A 1.48A,B 1.59A 1.50A,B 0.002

People following a gluten-free diet should only consume naturally gluten-free food and avoid specialty gluten- free products 2.40 2.31 2.22 2.05 2.73 0.053

The gluten-free diet is a fad (when used outside of celiac disease and non-celiac gluten sensitivity) 4.29A 4.05A 3.52B 4.18A 4.04A < 0.001

People with celiac disease can consume small amounts of gluten 1.44 1.37 1.52 1.66 1.62 0.177

Pure, uncontaminated oats are safe for people with celiac disease 4.29 3.95 4.03 4.27 3.92 0.067

159

Table 14: Continued

People with celiac disease should have regular appointments with a Registered Dietitian 3.93 3.91 3.86 3.83 3.85 0.929

Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans) 4.00B 4.20A,B 4.48A 4.20A,B 4.12A,B 0.025

Products that are naturally gluten-free should use a gluten-free label 3.11B 3.34A,B 3.64A 3.32A,B 2.92B 0.012

People following a gluten-free diet should ignore gluten-free labels and just look at the ingredient list 3.20A 3.02A 2.93A,B 2.83A,B 2.50B 0.029

There are enough gluten- free options on the market for those following a gluten-free diet 3.71 3.61 3.49 3.66 3.46 0.535

Specialty gluten-free products are nutritionally comparable to similar gluten-containing products 2.61 2.64 2.98 2.76 3.00 0.053 a1=Strongly disagree, 2=Slightly disagree, 3=Neither agree nor disagree, 4=Slightly agree, 5=Strongly agree

160

Table 15

Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as Reported by Registered Dietitians, Based on Hispanic or Latinoa (n = 448) Mean score Yes No (n = Question (n = 13) 435) P value

A gluten-free diet is appropriate for the general population 1.82 1.55 0.814

Non-celiac gluten sensitivity (NCGS) is recognized as a diagnosable condition 3.08 3.30 0.493

A gluten-free diet is effective for weight loss 2.15 1.82 0.255

The general public knows what gluten is 1.82 1.49 0.558

People following a gluten-free diet should only consume naturally gluten-free food and avoid specialty gluten-free products 2.85 2.22 0.067

The gluten-free diet is a fad (when used outside of celiac disease and non-celiac gluten sensitivity) 3.92 4.05 0.714

People with celiac disease can consume small amounts of gluten 2.54 1.48 < 0.001

Pure, uncontaminated oats are safe for people with celiac disease 4.15 4.12 0.913

People with celiac disease should have regular appointments with a Registered Dietitian 3.92 3.88 0.878

Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans) 4.31 4.19 0.704

Products that are naturally gluten-free should use a gluten-free label 3.46 3.29 0.621

People following a gluten-free diet should ignore gluten-free labels and just look at the ingredient list 3.23 2.96 0.442

There are enough gluten-free options on the market for those following a gluten-free diet 3.62 3.62 0.980

161

Table 15: Continued

Specialty gluten-free products are nutritionally comparable to similar gluten-containing products 3.23 2.72 0.099 a1=Strongly disagree, 2=Slightly disagree, 3=Neither agree nor disagree, 4=Slightly agree, 5=Strongly agree

162

Table 16

Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as Reported by Registered Dietitians, Based on Racea (n = 508)

Mean score

Black or Hispanic African Asian/Pacific White (n or Latino American Islander (n = Other (n Question = 478) (n = 7) (n = 6) 7) = 10) P value

A gluten-free diet is appropriate for the general population 1.57 1.29 1.33 1.14 1.80 0.537

Non-celiac gluten sensitivity (NCGS) is recognized as a diagnosable condition 3.34 3.00 4.00 3.00 2.60 0.110

A gluten-free diet is effective for weight loss 1.81 1.86 2.33 1.71 2.30 0.452

The general public knows what gluten is 1.49 1.57 1.17 1.43 1.40 0.875

People following a gluten-free diet should only consume naturally gluten- free food and avoid specialty gluten-free products 2.29A,B 3.29A 1.67B 1.43B 2.50A,B 0.041

163

Table 16: Continued

The gluten-free diet is a fad (when used outside of celiac disease and nonceliac gluten sensitivity) 4.06 3.86 3.67 4.14 3.80 0.857

People with celiac disease can consume small amounts of gluten 1.45B 2.29A,B 2.83A 1.86A,B 2.00A,B < 0.001

Pure, uncontaminated oats are safe for people with celiac disease 4.16A 3.71A,B 3.83A,B 2.71B 4.10A 0.020

People with celiac disease should have regular appointments with a Registered Dietitian 3.87 4.00 4.17 4.43 4.00 0.567

Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans) 4.20 4.00 4.50 3.57 4.00 0.515

Products that are naturally gluten- free should use a gluten-free label 3.30 3.43 3.17 3.57 3.40 0.971

164

Table 16: Continued

People following a gluten-free diet should ignore gluten-free labels and just look at the ingredient list 2.98 3.14 2.00 3.86 3.20 0.100

There are enough gluten-free options on the market for those following a gluten-free diet 3.60 3.71 4.17 4.00 4.20 0.248

Specialty gluten- free products are nutritionally comparable to similar gluten- containing products 2.72 3.14 3.83 3.29 2.60 0.053 a1=Strongly disagree, 2=Slightly disagree, 3=Neither agree nor disagree, 4=Slightly agree, 5=Strongly agree

165

Table 17

Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as Reported by Registered Dietitians, Based on Regiona (n = 508)

Mean score

West Northeast Midwest South (n (n = P Question (n = 97) (n = 144) = 174) 93) value

A gluten-free diet is appropriate for the general population 1.40 1.56 1.61 1.62 0.270

Non-celiac gluten sensitivity (NCGS) is recognized as a diagnosable condition 3.26 3.32 3.34 3.38 0.904

A gluten-free diet is effective for weight loss 1.74B 1.68B 1.88A,B 2.04A 0.047

The general public knows what gluten is 1.44 1.49 1.44 1.61 0.372

People following a gluten-free diet should only consume naturally gluten-free food and avoid specialty gluten-free products 2.23A,B 2.08B 2.39A,B 2.48A 0.045

The gluten-free diet is a fad (when used outside of celiac disease and non-celiac gluten sensitivity) 4.07 3.99 4.08 4.04 0.923

People with celiac disease can consume small amounts of gluten 1.47 1.38 1.63 1.43 0.150

Pure, uncontaminated oats are safe for people with celiac disease 3.97 4.19 4.08 4.30 0.222

People with celiac disease should have regular appointments with a Registered Dietitian 3.74 3.97 3.95 3.77 0.159

Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans) 4.29 4.23 4.22 3.96 0.148

166

Table 17: Continued

Products that are naturally gluten-free should use a gluten-free label 3.44 3.28 3.34 3.13 0.363

People following a gluten-free diet should ignore gluten-free labels and just look at the ingredient list 2.84 2.97 3.01 3.13 0.421

There are enough gluten-free options on the market for those following a gluten-free diet 3.58 3.63 3.52 3.85 0.133

Specialty gluten-free products are nutritionally comparable to similar gluten-containing products 2.55 2.80 2.87 2.60 0.052 a1=Strongly disagree, 2=Slightly disagree, 3=Neither agree nor disagree, 4=Slightly agree, 5=Strongly agree

167

Table 18

Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as Reported by Registered Dietitians, Based on Level of Educationa (n = 508)

Mean score

Doctoral Professional Master’s Bachelor’s P Question (n = 6) (n = 48) (n = 231) (n = 223) value

A gluten-free diet is appropriate for the general population 2.17 1.46 1.50 1.62 0.160

Non-celiac gluten sensitivity (NCGS) is recognized as a diagnosable condition 3.50 3.38 3.39 3.24 0.533

A gluten-free diet is effective for weight loss 2.00 2.04 1.80 1.80 0.481

The general public knows what gluten is 2.00 1.38 1.42 1.57 0.073

People following a gluten- free diet should only consume naturally gluten- free food and avoid specialty gluten-free products 3.00 2.46 2.32 2.20 0.231

The gluten-free diet is a fad (when used outside of celiac disease and non-celiac gluten sensitivity) 3.67 3.83 4.15 4.00 0.220

People with celiac disease can consume small amounts of gluten 1.50 1.50 1.52 1.47 0.965

Pure, uncontaminated oats are safe for people with celiac disease 3.33 4.00 4.15 4.16 0.321

People with celiac disease should have regular appointments with a Registered Dietitian 4.17 3.81 3.90 3.87 0.834

168

Table 18: Continued

Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans) 3.83 4.02 4.19 4.24 0.532

Products that are naturally gluten-free should use a gluten-free label 3.50 3.29 3.22 3.39 0.509

People following a gluten- free diet should ignore gluten-free labels and just look at the ingredient list 3.00 3.25 3.05 2.86 0.161

There are enough gluten- free options on the market for those following a gluten- free diet 3.33 3.56 3.70 3.56 0.482

Specialty gluten-free products are nutritionally comparable to similar gluten-containing products 2.50 2.71 2.70 2.79 0.758 a1=Strongly disagree, 2=Slightly disagree, 3=Neither agree nor disagree, 4=Slightly agree, 5=Strongly agree

169

Table 19

Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as Reported by Registered Dietitians, Based on Number of Years as a Registered Dietitiana (n = 508)

Mean score

0-4 40+ years 10-19 20-29 30-39 years (n = 5-9 years years (n years (n years (n (n = Question 34) (n = 116) = 168) = 97) = 72) 20) P value

A gluten-free diet is appropriate for the general population 1.44B,C 1.48A,B,C 1.55A,B 1.86A 1.49A,B,C 1.15C 0.007

Non-celiac gluten sensitivity (NCGS) is recognized as a diagnosable condition 3.35 3.34 3.22 3.41 3.49 3.10 0.502

A gluten-free diet is effective for weight loss 1.62 1.80 1.93 1.89 1.76 1.45 0.283

The general public knows what gluten B B A,B B A B is 1.35 1.31 1.58 1.41 1.76 1.35 0.002

People following a gluten-free diet should only consume naturally gluten-free food and avoid specialty gluten-free products 2.79 2.42 2.24 2.25 2.07 2.00 0.051

The gluten-free diet is a fad (when used outside of celiac disease and non-celiac gluten sensitivity) 4.35 4.17 4.07 3.74 4.06 4.05 0.072

170

Table 19: Continued

People with celiac disease can consume small amounts of gluten 1.44 1.47 1.43 1.54 1.54 1.85 0.581

Pure, uncontaminated oats are safe for people with celiac disease 3.97 4.23 4.08 4.06 4.36 3.80 0.268

People with celiac disease should have regular appointments with a Registered Dietitian 3.97 3.90 3.96 3.88 3.71 3.75 0.568

Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans) 3.91B 4.08A,B 4.23A,B 4.52A 4.07A,B 3.95B 0.014

Products that are naturally gluten- free should use a gluten-free label 2.76C 3.14B,C 3.46A,B 3.69A 3.12B,C 2.65C < 0.001

People following a gluten-free diet should ignore gluten-free labels and just look at the ingredient list 3.44A 3.09A,B 3.08A 2.84B,C 2.78B,C 2.40C 0.013

There are enough gluten-free options on the market for those following a gluten-free diet 3.85 3.68 3.64 3.47 3.58 3.55 0.575

171

Table 19: Continued

Specialty gluten- free products are nutritionally comparable to similar gluten- containing products 2.78 2.54 2.73 2.92 2.82 2.70 0.227 a1=Strongly disagree, 2=Slightly disagree, 3=Neither agree nor disagree, 4=Slightly agree, 5=Strongly agree

172

Table 20

Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as Reported by Registered Dietitians, Based on if Area of Practice Includes Celiac Disease (n = 508)

Mean score

Yes No (n = Question (n = 254) 254) P value

A gluten-free diet is appropriate for the general population 1.56 1.56 0.923

Non-celiac gluten sensitivity (NCGS) is recognized as a diagnosable condition 3.36 3.29 0.456

A gluten-free diet is effective for weight loss 1.81 1.85 0.670

The general public knows what gluten is 1.49 1.48 0.912

People following a gluten-free diet should only consume naturally gluten-free food and avoid specialty gluten-free products 2.16 2.41 0.018

The gluten-free diet is a fad (when used outside of celiac disease and non-celiac gluten sensitivity) 4.04 4.06 0.822

People with celiac disease can consume small amounts of gluten 1.39 1.59 0.026

Pure, uncontaminated oats are safe for people with celiac disease 4.25 4.01 0.020

People with celiac disease should have regular appointments with a Registered Dietitian 3.93 3.84 0.281

Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans) 4.22 4.15 0.466

Products that are naturally gluten-free should use a gluten-free label 3.39 3.21 0.104

People following a gluten-free diet should ignore gluten- free labels and just look at the ingredient list 2.85 3.12 0.016

There are enough gluten-free options on the market for those following a gluten-free diet 3.73 3.51 0.023 173

Table 20: Continued

Specialty gluten-free products are nutritionally comparable to similar gluten-containing products 2.67 2.81 0.119 a1=Strongly disagree, 2=Slightly disagree, 3=Neither agree nor disagree, 4=Slightly agree, 5=Strongly agree

174

Table 21

Mean Scores for Gluten-Related Questions on a 5-Point Hedonic Scale as Reported by Registered Dietitians, Based on Diagnosis of Gluten-Related Disorder (Celiac Disease, Non- Celiac Gluten-Sensitivity, or Wheat Allergy) (n = 508)

Mean score

Yes No (n = Question (n = 44) 464) P value

A gluten-free diet is appropriate for the general population 1.82 1.53 0.051

Non-celiac gluten sensitivity (NCGS) is recognized as a diagnosable condition 3.50 3.51 0.282

A gluten-free diet is effective for weight loss 1.84 1.83 0.925

The general public knows what gluten is

People following a gluten-free diet should only consume naturally gluten-free food and avoid specialty gluten-free products 2.57 2.26 0.109

The gluten-free diet is a fad (when used outside of celiac disease and non-celiac gluten sensitivity) 3.57 4.09 0.005

People with celiac disease can consume small amounts of gluten 1.14 1.53 0.013

Pure, uncontaminated oats are safe for people with celiac disease 3.82 4.16 0.067

People with celiac disease should have regular appointments with a Registered Dietitian 3.80 3.89 0.525

Gluten should be included on a food label along with the top 8 allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans) 4.41 4.17 0.163

Products that are naturally gluten-free should use a gluten-free label 3.43 3.29 0.477

People following a gluten-free diet should ignore gluten- free labels and just look at the ingredient list 2.80 3.00 0.283

There are enough gluten-free options on the market for 3.45 3.64 0.289 175

Table 21: Continued those following a gluten-free diet

Specialty gluten-free products are nutritionally comparable to similar gluten-containing products 2.57 2.76 0.270 a1=Strongly disagree, 2=Slightly disagree, 3=Neither agree nor disagree, 4=Slightly agree, 5=Strongly agree

176

Appendix F: Pre- and Post-Laboratory Questionnaire

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185

186

Appendix G: Pre- and Post-Laboratory Consent Form

187

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Appendix H: 2016 Gluten-Free Laboratory Activity

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193

Appendix I: 2017 Gluten-Free Laboratory Activity

LABORATORY – FLOUR

Background

The term flour refers to finely ground meal. Using this general definition, “flours” can be prepared from a variety of foodstuffs, including buckwheat, oatmeal, potatoes, rye, rice, triticale, soybeans, corn, barley, chickpeas, peanuts and cottonseed. However, when used in recipes, the term flour is understood to mean all-purpose wheat flour, unless otherwise designated. Hard wheats, soft wheats and durum wheats are milled into wheat flour. Hard wheats are high in protein and are used to produce bread flours (13-14% protein). Soft wheats have a low protein content and are better suited to production of cake and pastry flours (7-8% protein). All-purpose flour (10-11% protein) is generally milled from a blend of hard and soft wheats. Durum wheats are high protein wheats which are particularly suitable for use in pasta products. Most wheat flours produced are white refined flours which are milled after the bran and germ have been removed from the cereal kernel. These refined flours are often enriched by replacing the niacin, thiamin, riboflavin and iron that was removed during refining. Addition of calcium and vitamin D is optional. Flour also undergoes chemical treatment after milling to hasten the bleaching and maturing of the flour. Whole wheat flour, milled from kernels that have not had the bran and germ removed, is available and has gained in popularity in recent years. Also available are self-rising flours, to which baking powder and salt have been added and instant zed flours, which have been specially processed to have instant blending properties with liquids.

Flour is a major ingredient in all baked products and contributes to their structure. Gliadins and glutenins are classes of proteins found in wheat. When flour and water are kneaded or mixed together, these proteins combine with water to form an elastic protein complex called gluten. The amount of gluten formed in a dough is dependent on the amount of protein in the flour. The gluten forms a continuous network throughout the dough or batter. As leaving gases expand during baking, the gluten strands stretch and the volume of the product increases. The gluten coagulates during baking and gelatinized starch granules become imbedded in the gluten network. This forms the basic structure or baked products. Gluten is normally considered to be a “toughening” agent. Gluten development contributes not only to structure but also to texture and decreases tenderness of baked products. Therefore, high protein flours are most suitable for breads and low protein flours are most suitable for cakes and pastries Gluten development is influenced both by the type of flour used and by the amount of manipulation. It also depends on the quantities of liquid, sugar and fat in a recipe. Enough water must be available for the desired amount of gluten to form. Sugar competes with proteins for available water and inhibits gluten development. Fat coats flour particles, making it difficult for water to 194 hydrate the gluten forming proteins, and also inhibits gluten development. Fat is the more effective inhibitor of gluten development.

Toughening Agents Tenderizing Agents Gluten Fat (coats gluten) Water Sugar (binds water) Manipulation

Objectives

1. To demonstrate the preparation of gluten. 2. To compare the yield of gluten from different types of flours. 3. To show the effect of sugar on gluten formation. 4. To show the effect of fat on gluten formation. 5. To compare the volume, texture and flavor of cakes prepared using different types of flour. 195

Procedures

A. Preparation of Gluten

1. Use 120 g of whichever flour is assigned to you. 2. Measure out about 60 ml water. Add water gradually to the flour while mixing with a fork. The objective is to form a stiff dough which is not sticky so that it can be easily kneaded. It may not be necessary to use all 60ml of the water. With some flours it may be necessary to use more than 60ml. Do this step carefully. 3. Place the dough on the countertop and knead until the dough is smooth and elastic, about 10 minutes. Do not add more flour. 4. Wrap the dough in a double layer of cheesecloth. Manipulate the dough with gentle pulling and squeezing in a large bowl of cool water or under a cool running faucet. The water will become cloudy as starch is washed out. 5. Continue the washing procedure until the water no longer appears cloudy. If using a large bowl of water, change water often. 6. Gather the gluten into a smooth ball. It may be necessary to scrape the gluten off the cheesecloth. Do this as thoroughly as possible. Check through the raw gluten ball to be sure no pockets of starch remain. If starch is present, continue washing. 7. Place the gluten ball on a baking sheet. Bake for 15 minutes at 425 F. Reduce temperature to 300 F and continue baking for 30 minutes. Cool. 8. Weigh the cooled, baked gluten ball. Record the weight. 9. Measure the volume of the baked gluten ball. Place baked gluten in a large calibrated beaker or glass measuring cup. Fill with sugar or rapeseed to a selected calibration mark, making sure that the gluten is completely covered. Record the total volume (VT). Pour out the sugar or rapeseed into a graduated cylinder. Record the volume (V) of sugar or rapeseed used. Calculate the volume (VG) of the gluten ball. (VG = VT- V). 10. Place on a small plate and label. 11. Do not discard the gluten balls.

B. Effect of Flour Type on Cake

¾ cup sugar 1 ¼ teaspoons double-acting baking powder ¼ cup shortening ½ teaspoon salt 1 egg ½ cup milk 1-1/2 cups flour (assigned by your GA) ½ teaspoon vanilla

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1. Sift the flour, salt and baking powder together twice. 2. Add the vanilla to the milk. 3. Add the sugar to the shortening, 4 tablespoons at a time, creaming 100 strokes after each addition. 4. Add the egg to the creamed mixture, stir until blended, and mix for 1 minute with an electric mixer at medium speed. 5. Add 1/3 of the flour mixture and 1/3 of the milk mixture. Mix for 1 minute with an electric mixer at medium speed. Repeat two more times until all of the flour and milk is incorporated. 6. Continue mixing for 2 minutes with an electric mixer at high speed. 7. Transfer batter to a greased and floured 8-inch square baking pan. 8. Bake at 375 F for approximately 30 minutes. Cake is done when it pulls away from the sides of the pan slightly. Doneness may also be tested by gently pressing the surface of the center of the cake with your fingertip. If the cake springs back after pressing, it is ready to remove from the oven. 9. Cool cake in the pan. after cooling, cut into pieces for class evaluation. 10. Evaluate volume (height), texture and flavor of each cake prepared.

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Datasheet

A. Preparation of Gluten

Type of Appearance Weight Volume Flour

B. Effect of Flour Type on Cake

Type of Volume Texture Flavor Flour

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Study Questions

1. Why do different types of flour require different amounts of water to form a stiff dough? 2. What is the purpose of “kneading” the flour –water mixture? 3. Explain how you can separate the protein and starch components of flour. How could you collect the starch? 4. Why was the gluten ball baked at two different temperatures? 5. What is the primary leavening agent in a gluten ball? The secondary leavening agent? 6. How did the addition of sugar and fat affect gluten yield? Explain Why. 7. If starch is incompletely removed from the dough during the washing procedure, how would this affect the volume of the baked gluten ball? Why? 8. What changes occur in the gluten proteins during baking? 9. Rank the gluten balls according to volume, from largest to smallest. Were these the expected results? 10. Rank the gluten balls according to volume, from largest to smallest. Were these the expected results? 11. Which cake had the highest volume? The lowest volume? Why? 12. Which cake had the finest crumb? The coarsest crumb? Why? 13. If triple the amount of sugar was used, how might this affect the final cake volume? 14. If the flour is not sifted before measuring, how might this affect the final cake volume?

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