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2003-07-01

Effects of long-term storage on quality of regular and quick rolled

M. B. McEwan [email protected]

Lynn V. Ogden

Oscar A. Pike [email protected]

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BYU ScholarsArchive Citation McEwan, M. B.; Ogden, Lynn V.; and Pike, Oscar A., "Effects of long-term storage on quality of regular and quick rolled oats" (2003). Faculty Publications. 39. https://scholarsarchive.byu.edu/facpub/39

This Poster is brought to you for free and open access by BYU ScholarsArchive. It has been accepted for inclusion in Faculty Publications by an authorized administrator of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. Effects of long-term storage on quality of regular and quick rolled oats M. McEwan, L. V. Ogden and O.A. Pike Department of Nutrition, Dietetics and Food Science Brigham Young University Provo, UT 84602

ABSTRACT B and E determination Sensory Analysis Content 1 CONCLUSIONS There exists a market for food packaged for long term storage, for such uses as Vitamin analyses were conducted using an Agilent Model 1100 high Hedonic scores varied from 3.8-6.5 (Fig. 4). The two heat-abused Vitamin B1 content varied between brands with values ranging from emergency relief efforts, military rations, and personal storage. The objective of performance liquid chromatograph (Agilent Technologies, Palo Alto, CA). samples were lower than other samples in most of the categories of 1.22 to 7.32 μg/g (Fig. 6). The USDA Nutritent Database for Standard There was a loss of some aspects of quality in Vitamin B (thiamin) content was measured with the method of Ndaw and commercially packaged canned rolled oats in this research was to investigate the quality of regular and quick rolled oats 1 sensory analysis and were eliminated from data analysis. Regular rolled Reference value for Vitamin B1 in dried rolled oats is 7.3 μg/g. (USDA, others (2000) using a C18 reverse phase column (Phenomenex, Inc., commercially packaged in cans for long-term storage. oats were significantly preferred over quick cooking in flavor, texture and 2003). Most samples fell below this amount. Surprisingly, many of the residential storage throughout the time period studied. Torrence, CA) and a fluorometric detector. content was measured overall acceptability. Using regression analysis, age of samples older brands had higher vitamin B levels than many of the newer However, even after 28 years of storage all samples using the method of Peterson (1993) with a normal phase μ Prisol column 1 significantly affected hedonic scores for aroma, texture, flavor and overall brands. There was no significant difference in vitamin B content Twenty samples of rolled oats packaged in No. 10 cans representing seven (Waters Corp., Milford, MA) and a fluorometric detector Determinations 1 were considered acceptable for use in an emergency acceptability. Flavor and texture were significantly affected by oxygen between types of rolled oats. brands were obtained from donors in five states. Samples had known were carried out under subdued light. situation by at least three-fourths of consumer levels. Texture was affected by type; regular rolled oats were preferred panelists. Manufactures must observe good packaging dates and approximate storage conditions, and ranged in age from over quick cooking. Results (Fig. 5) indicate that even after 28 years of Vitamin E levels varied significantly among brands, with values ranging 1-28 years. A 50-member consumer panel evaluated aroma, texture, flavor, Headspace Hexanal Concentration manufacturing practices to ensure the longest possible Hexanal was measured following AOCS Recommended Practice Cg 4-94 storage 95% of rolled oats stored in a reduced oxygen atmosphere at from 1.1 to 36 μg/g (Fig. 7). There was no significant difference shelf life and consumers must store rolled oats under aftertaste, and overall acceptability using a 9-point hedonic scale. Can between type. Peterson (1995) found that fresh rolled oats had an using a Perkin-Elmer Headspace Sampler Model HS-40XL and a Hewlett- ambient temperatures would be acceptable to three-fourths of the recommended storage conditions to maximize shelf- headspace oxygen, can seam quality, and water activity of each sample was Packard 5890 Series II Plus gas chromatograph equipped with a flame population for use in an emergency situation . average total tocol concentration of 28.3 μg/g. Approximately half the life. Rolled oats can be an important part of a long- also measured. Vitamins B1 and E were measured as well as headspace ionization detector. Briefly, 2 gm of ground rolled oats were placed in a 22 9 samples had total tocol levels similar to this level, indicating it is hexanal concentrations. ml glass vial and 6 ml of distilled water was added. The vial was heated for A Quick cooking possible to store rolled oats such that little loss of vitamin E occurs. term food storage plan because of their sensory and 8 Regular 40 min at 60°C before headspace volatiles were injected into the nutritional stability when properly packaged and stored. 7

a a b c d a b c chromatograph. a b a b c a b c d e a b c d b c d e f b c d e f b c d e f 6 g c d e f Hedonic scores for overall acceptability varied from 3.8-6.5. Besides two heat g f e f g g f d e f g Headspace Hexanal abused samples, all brands had a hedonic score of 5.0 or above (neither like 5 * Data Analysis * Headspace hexanal concentrations varied from 0.002 to 0.138 μg/g nor dislike) Headspace oxygen ranged from .43% - 20.7%. Wide variation in Data was analyzed for significance using Statistical Analysis System 4 (Fig. 8). One of the heat abused samples had high hexanal levels and REFERENCES can seam quality was observed. Water activity ranged from .45 to .62. Regular software (SAS Institute, 1999). A mixed model analysis of variance (PROC Aroma (Hedonic Score) 3 the other, low. This is attributable to the amount of oxygen in the oats were significantly preferred over quick cooking oats in flavor, texture, and MIXED) was used for the sensory data. PROC GLM was used for the water 2 headspace of the respective samples. Hexanal values correlated with Fritsch CW, Gale JA. 1977. Hexanal as a measure of activity and vitamin data. Both models used Duncan’s Multiple Range Test 1 2 overall acceptability. Using regression analysis, age of sample significantly <1A <1B 3 4 6 7 8 10A 10B 11 12A 12B 13 14 17 21 23 28 percent headspace oxygen levels, with an r value of 0.60 (data not rancidity in low foods. J Am Oil Chem Soc 54:225. affected hedonic scores for aroma, texture, flavor and overall acceptability. to determine significant differences between means. Significant differences Sample Number (Age in Years) shown). Headspace hexanal and vitamin E levels were correlated, with were defined as p<0.05. Heat abused samples were excluded from 9 an r2 value of 0.80 (data not shown), suggesting the effectiveness of Ndaw S, Bergaentzle M, Aoude-Werner D, Hesselmann Flavor and texture was significantly affected by oxygen level. Texture was B Quick cooking statistical analysis. Correlations were run using Microsoft Excel statistical 8 Regular vitamin E in delaying lipid oxidation of the samples. However, higher C. 2000. Extraction procedures for the liquid significantly affected by type of rolled oats. Vitamin B amounts varied and software. 7 1 a a b a b c a b c a b c a b c b c d b c d e chromatographic determination of thiamin, riboflavin and c d e f hexanal values did not correlate with lower sensory scores. It is

6 d e f g were actually higher in some older samples. Vitamin E levels and hexanal e f g h f g h i

g h i g h i h i 5 i possible that off flavors present in the uncooked product were vitamin B6 in foodstuffs. Food Chem 71:129-138. levels were correlated. * RESULTS 4 * volatilized during cooking. Flavor (Hedonic Score) 3 Norseth AL. 1986. Storage of low-moisture foods: Effects Headspace Oxygen, Seams, and Water Activity 8 Although there was a loss of some aspects of product quality over time, all 2 of storage temperature, time and oxygen level on Quick cooking Headspace oxygen ranged from 0.43% - 20.7% (Fig. 1). Two 1 samples were considered acceptable. Manufactures must observe good <1A <1B 3 4 6 7 8 10A 10B 11 12A 12B 13 14 17 21 23 28 Regular consumer acceptability and nutrient content. [M Sc thirds of the cans had headspace oxygen levels ≤ 2%. Both Sample Number (Age in Years) 6 Both manufacturing practices to ensure the longest possible shelf life and consumers 9 Thesis]. Provo, UT: Brigham Young Univ. 216 p. Available Quick cooking

g/g) nitrogen flushing and the use of oxygen absorbers were effective in C * 8 Regular

(

must store rolled oats in recommended storage conditions to maximize shelf- 1 from: Harold B. Lee Library, Provo, UT. 4 lowering headspace oxygen to ≤ 2%. The results of CO2 flushing 7 a a b a a b a b c d a b c life. a b c a b c d a b c d b c d b c d e 6 d e b c d

were mixed. Wide variation in can seam quality was observed * Vitamin B e f

b c d * f Peterson D. 1995. tocols: Concentration and stability (Fig. 2). Though poor seams can account for high headspace 5 2 * in oat products and distribution within the kernel. oxygen, at least two samples with poor seams had < 2% oxygen. 4

INTRODUCTION Texture (Hedonic Score) 3 Chem 72(1):21-24. Water activity ranged from 0.45 to 0.62 (Fig. 3). 0 Traditionally, shelf life studies of cereal staples have investigated quality over a 2 1 3 4 6 7 8 10 11 12A 12B 13 14 17 21 23 28 Sample Number (Age in Years) 1 period of several months. Norseth (1986) found that rolled oats stored 3 years <1A <1B 3 4 6 7 8 10A 10B 11 12A 12B 13 14 17 21 23 28 USDA. 2003. United States Department of Agriculture Sample Number (Age in Years) Fig. 6 Vitamin B1 in uncooked rolled oats stored up to 28 years. Bars 0.7 National Nutrient Database for Standard Reference. at 38 C still had acceptable sensory properties. However, there is a market for N Flush 9 2 Quick cooking represent standard deviation for samples with duplicates for that year.

CO Flush D 2 Regular Quick cooking 8 Dashed line indicated vitamin B level in uncooked rolled oats from the Available online: http://www.nal.usda.gov/fnic/cgi- 0.6 Regular 1 product that will store for much longer periods of time, intended for such uses 20 O2 Absorber 7 USDA National Nutrient Database for Standard Reference. The asterisks bin/nut_search.pl a as emergency relief efforts, military rations, and personal storage. Rolled oats 0.5 a b a b c a b c a b c a b c

b c d b c d 6 c d indicate heat-abused samples that were excluded from data analysis. a b c 15 d e e f e f f in hermetically sealed cans are available on the retail level, yet little work has f 5 0.4 f * investigated the effects of long-term storage on quality. 4 50 * 10 0.3 Quick cooking 3 Aftertaste (Hedonic Score) Regular Water Activity ACKNOWLEDGEMENTS 40 Both 0.2 2 The objective of this research was to investigate the quality of regular and Headspace Oxygen (%) 5 1 <1A <1B 3 4 6 7 8 10A 10B 11 12A 12B 13 14 17 21 23 28 quick cooking rolled oats packaged in cans for long-term storage. 0.1 Sample Number (Age in Years) g/g) 30 The authors appreciate the funding for this research

9 0 provided by Ira Fulton and the contributions of the 0.0 E Quick cooking <1A <1B 3 4 6 7 8A 8B 10A 10B 11 12A 12B 13 14 17 21 23A 23B 28 20 <1A <1B 3 4 6 7 8A 8B 10A 10B 11 12A 12B 13 14 17 21 23A 23B 28 8 Regular Sample Number (Age in Years) Sample Number (Age in Years) Vitamin E ( following individuals: Devin Rose, Aram Sloan, Lilon 7 a a b a b a b a b c a b a b c Bunn, Tyler Oesterle, Heather Farnsworth, Michelle METHODOLOGY b c b c 10 Fig. 1 Headspace oxygen in cans of 6 c d Fig. 2 Water activity of rolled oats d e d e e e e Lloyd, Theresa Gnadt, Melanie Halling and Jipeng Zou. Samples 5 rolled oats stored up to 28 years. * stored in cans up to 28 years. 0 Twenty samples of rolled oats packaged in No. 10 cans representing seven manufacturers 4 * 1 3 4 6 7 8 10 11 12A 12B 13 14 17 21 23 28 Sample Number (Age in Years) were obtained from donors in five states. Samples included two types of rolled oats, 3

regular and quick cooking. Samples ranged in age from 1-28 years and had been stored at Overall Acceptibility (Hedonic Score) 2 Fig. 7 Vitamin E results for uncooked rolled oats. Bars represent standard various residences at approximately the same temperature throughout the time period. All 1 deviation for samples with duplicates for that year. Dashed line represents <1A <1B 3 4 6 7 8 10A 10B 11 12A 12B 13 14 17 21 23 28 samples were stored at room temperature or below, except for two samples stored at Sample Number (Age in Years) total tocol in fresh rolled oats (Peterson 1995). The asterisks indicate heat- elevated, abusive temperatures which were included in the study for comparison. Fig. 4. Sensory scores of cooked rolled oats. Graph A is aroma, B is flavor, C is texture, abused samples that were excluded from data analysis. D is aftertaste, E is overall acceptability. Like superscripts indicate no significant difference. The asterisks indicate heat-abused samples that were excluded from data 0.16 Headspace Oxygen, Can Seam and Water Activity analysis. 0.14 Quick cooking Regular Headspace oxygen was measured using a 3500-Series Headspace Oxygen Analyzer 100 0.12 Both

g/g) (Illinois Instruments, Inc., Johnsburg, IL). Can seams were evaluated using the SeamMate 0.10 90 System (Onevision Corporation, Westerville, OH) to measure the following seam 0.08 dimensions: thickness, width, body hook, cover hook, and overlap. Seam tightness was 0.06 80 rated on a scale of 0-100%. The seams were given an overall rating of good, satisfactory, 0.04

or poor by an experienced evaluator. Water activity was measured using an Aqualab CX-2 Headspace Hexanal ( 0.02 70 Presented at the Annual Meeting of the Institute of Food (Decagon Devices, Inc., Pullman, WA). 0.00 Technologists in Chicago, IL July 2003 60 1 3 4 6 7 8 10 11 12A 12B 13 14 17 21 23 28 Sensory Analysis Sample Number (Age in Years)

Sensory analysis was conducted at the BYU Sensory Laboratory using standard Acceptance (% who would use in emergency) 50 Fig. 8 Headspace hexanal concentrations in uncooked rolled oats. Bars procedures. A 50-member consumer panel evaluated prepared for aroma, flavor 0 4 8 12 16 20 24 28 Age (Years) represent standard deviation for samples with duplicates for that year. texture, aftertaste, and overall acceptability using a 9-point hedonic scale. Percent Fig. 3 Can seam cross section, tightness rating and The asterisks indicate heat-abused samples that were excluded from acceptance was determined by asking panelists if they would use the sample in an Fig. 5 Sample age compared to percentage of panelists who would use each sample overall seam rating, for each sample of canned rolled in an emergency situation. Dashed lines represent 95% prediction interval. data analysis. emergency situation. oats.