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NUTRITION AND FOOD GRAINS

Food Grains and Well-Being

Contents Functional Foods: Overview Functional Foods: Dietary Fibers, Prebiotics, Probiotics, and Synbiotics Nutrition: Soy-Based Foods

Functional Foods: Overview G Bultosa, Botswana College of Agriculture, Gaborone, Botswana; Haramaya University, Dire Dawa, Ethiopia

ã 2016 Elsevier Ltd. All rights reserved.

Topic Highlights Consumption of an adequately balanced diet is a means of body structure formation, energy generation, and health. More • Functional food concepts/definitions. than 2500 years ago, ‘Let foods be our medicine and medicine • Bioactive compounds. be our foods’ was stated by Hippocrates. This shows that • Chronic diseases and functional foods. consumption of diets with health-promoting effects is not • -free foods for celiac patients. new. But evidence on the relationship between dietary chem- ical component(s) and health is on evolutionary development as technology and human comprehension advance. Within Learning Objectives such evolution, the concept of functional foods was started in the 1980s as Foods for Specified Health Use (FOSHU) • To achieve understanding on the concepts/definitions of in Japan. Foods, when consumed as a regular diet that supplies functional foods. one or more bioactive components beyond basic and • To achieve understanding of bioactive compounds used in offer health-promoting effects, are today branded as functional functional foods, grain dietary sources, and potential effects foods. Functional foods are not prescribed drugs, dietary sup- on health. plements, medical foods of therapeutic effects, traditional • To impart processing principles on grain-based functional medicines, or nutraceuticals. Functional foods are distinct foods. from macronutrient and micronutrient supplements targeted to achieve balanced diets and to treat deficiency syn- dromes. Functional foods thus comprise whole foods, forti- Introduction fied, enriched, or enhanced foods bearing bioactive compounds beyond macro- and micronutrients. Sources of Humankind has progressed from a hunter-gather approach to bioactive ingredients include whole grains, flaxseed, sesame food consumption to sedentary agriculture, progressing through , psyllium seed , legumes (soybean and fenugreek), the industrial revolution to our current knowledge-based society fruits, vegetables, herbs, spices, and fermented foods. The with advances in food processing. There is now enormous evi- nature of bioactive compounds derived from such sources is dence about the limitations of consuming specific food variable even though similarities also exist. Those recognized component(s) on human health. The twenty-first century of bioactive compounds include phenolics; ; dietary humankind is marked by lifestyle changes resulting in the con- fibers; b-glucans and inulin-type fructans; o-3 fatty acids; pro- sumption of diets high in calories, , cholesterol, and sodium biotics, prebiotics, and synbiotics; ; soy and inadequate intakes of calcium, iron, , and dietary fibers ; plant stanols and sterols; isothiocyanates; polyols; and an increased resistance of pathogens to drugs. These factors, and some minerals and . In some respects, there is coupled with less physical exercise, aging populations, and an overlap with food bioactives recognized to be functional more leisure time, have exposed much of the world’s population ingredients and micronutrients such as in the case of vitamins to cancers and various metabolic syndrome-related diseases, and minerals. Most bioactive compounds present in functional osteoporosis, dementia, etc. Some genetically predisposed foods are not necessarily essential for life but are recognized individuals are also affected by diet-caused allergens. contributors toward good health.

Encyclopedia of Food Grains, Second Edition http://dx.doi.org/10.1016/B978-0-12-394437-5.00071-1 1 2 FOOD GRAINS AND WELL-BEING | Functional Foods: Overview

The World Health Organization (WHO) recommends to the food to which a component has been added to provide benefits; public to move toward healthful diets. The functional-food a food from which a component has been removed by techno- expansion across the globe is enormous with the current market logical or biotechnological means so that the food provides size estimated from 7 to 190 billion USD. The ever-increasing benefits not otherwise available; a food in which a component health-care costs and public awareness on roles of diet on health has been replaced by an alternative component with favorable are contributing factors for such expansion. Functional-food properties; a food in which a component has been modified by development involves evaluation of the roles, safety, and con- enzymatic, chemical, or technological means to provide a bene- sumer acceptance of bioactive compounds. For foods that have fit; a food in which the bioavailability of a component has been no history of consumption as regular diets (novel foods), the modified and combination of any of the above. evaluation and regulatory requirements are rigorous and are In Japan, FOSHU refers to foods consumed as part of an required to be substantiated by scientific evidence for their ordinary diet, containing functional ingredients and exerting efficacy and safety. As a result, even though a number of novel health or physiological effect. FOSHU requires that safety foods were developed in the past, their wider expansion was assessment, health functions, and claims must be approved limited. by the Ministry of Health, Labour, and Welfare. Functional Various grain-based functional foods are today on the mar- foods are also required to have three other fundamental fea- ket in the form of snacks, baked foods, extruded tures: (1) nutritional functions, (2) sensory functions, and (3) products, ready-to-eat breakfast , fermented cereals, bev- physiological functions such as regulation of biorhythms, the erages, and gruels. Other products are: dietary fibers, inulin- nervous system, the immune system, and body defense beyond type fructans, b-glucans, carotenoids, o-3 fatty acids, plant nutrient functions. As of April 2011, in Japan, 955 products sterols, and/or stanols-fortified products. There are also indig- were approved as FOSHU. enous foods that are a heritage of a given community and their Based on extensive literature review and expert consultation, record as safe diet is lost in antiquity and yet most of them “A functional food is, or appears similar to be, a conventional fulfill what is expected of functional foods. food. It is part of a standard diet and is consumed on a regular In this article, functional food definitions, distinction from basis, in normal quantities. It has proven health benefits that related concepts, recognized bioactive ingredients, dietary reduce the risk of specific chronic diseases or beneficially affect sources, health benefits, and processing principles are target functions beyond its basic nutritional functions.” described giving emphasis on grains. Read also functional Even though there are slight variations, the following are foods: dietary fibers, prebiotics, probiotics, and synbiotics as reflected on definitions given by different sources: (1) func- these are not covered here. tional foods should be consumed as part of regular safe diet not as drugs; (2) they are required to bear functionally bioac- tive adequate ingredient(s) beyond basic nutrients; (3) diet Functional Food: Concepts and Definitions with its functionally bioactive ingredient(s) should impact positive health in an individual by either (i) decreasing occur- So far, there is no global consensus on the definition of func- rences of disease(s), (ii) decreasing disease-causing factor(s), or tional foods. The Codex Alimentarius Commission only issued (iii) promoting positive human physiological functions for guidelines (CAC/GL 23–1997) on nutrition and health claims optimal health such as by maintaining body homeostasis to be used through consultation with country policy. However, and/or through bolstering body immune systems; (4) they food regulatory agencies and various professional societies in should improve quality of life; and (5) if there is no history different countries have described closely related concepts/ of consumption as a regular diet, they must pass a strict regu- working definitions. Definitions offered from various sources latory evaluation process for their safety and for beneficial for functional foods, features, and requirements on what con- claim(s) declared substantiated with sound scientific evidence. stitute to be nutrition, health, and structure/function claims are listed under the Further Reading section. According to the ADA, “all foods are functional at some Other Concepts Related to Functional Foods physiological level because they provide nutrients or other Nutraceuticals substances that furnish energy, sustain growth, or maintain/ repair vital processes. However, functional foods are recog- These are distinct from functional foods and defined as a nized to provide additional health benefits that may reduce product isolated or purified from foods generally sold in disease risks and/or promote optimal health. Functional foods medicinal forms (i.e., as pills, powder, syrups, or other medic- include: (1) conventional foods or whole foods, (2) modified inal forms) that have specific health benefits. foods, (3) medical foods, and (4) foods for special dietary use.” According to Functional Food Science in Europe, “Functional Dietary Supplements foods are those satisfactorily demonstrated to affect beneficially one or more target functions in the body, beyond adequate These are products other than tobacco intended to supplement nutritional effects, in a way that is relevant to either an improved diet, which contain one or more of the following dietary ingre- state of health and well-being and/or reduction of risk of disease dients: , , herb or other botanical, amino acid, when consumed as part of normal food pattern.” Thus, func- concentrate, metabolite, constituent, extract, or combinations tional foods include: a natural, unmodified food; a food in of these ingredients; they are ingested in pill, capsule, tablet, or which one of the components has been enhanced through spe- liquid form; they are not represented for use as conventional cial growing conditions, breeding, or biotechnological means; a food or as a sole item of diet. FOOD GRAINS AND WELL-BEING | Functional Foods: Overview 3

Novel Foods and alcohols) in (Figure 2). Alkyl- resorcinol metabolites are currently studied for use as These are defined as raw foods or food materials with no biomarkers of whole-grain intake. also contains vitamins, history of safe use, for example, genetically modified foods; phytosterols, minerals, proteins, lipids, carotenoids, tocols, foods produced by algae, fungi, or microorganisms; foods and phytic acids. Consumption of grain foods along with isolated from plants and animals without a history of safe their bran is beneficial due to the presence of various bioactive use; and foods that have been processed where the process compounds. Functional roles documented for phenolics has dramatically changed the food. include: bolstering of cellular antioxidant defenses, protection from cardiovascular disease (CVD) risks, brain wellness, anti- Bioavailability neurodegenerative, antiulcer, anticarcinogenic, antimutagenic, anti-inflammatory, antimicrobial properties; and improve- This refers to a fraction of a given compound and/or its metab- ment of eye health and vision, muscle performance, and olite that reaches systemic circulation and involves gastrointes- immune responses. tinal digestion, absorption, metabolism, and tissue Phenolics are generally partially bioavailable and their distribution. Bioavailability encompasses bioaccessibility and properties are influenced by their structures and solubility. bioactivity. Most soluble phenolics are found unbound, whereas insolu- bles are found bound to cell wall polysaccharides or proteins Bioaccessibility where they form stable complexes. Insoluble phenolics are not absorbed in the small intestine, but they are fermented by This refers to the quantity or fraction of a bioactive that is colon microbiota yielding largely ferulic acid followed by released from a food matrix in the gastrointestinal tract and p-coumaric acid. Within cells, phenolics suppress reactive- becomes available for absorption. It includes digestive trans- oxygen (ROS) and nitrogen species (RNS) by donating hydro- formations, absorption/assimilation into intestinal epithelium gen atoms or electron, quenching free radicals, and activating cells, and also the presystemic metabolism (both intestinal and endogenous antioxidant enzymes. They also chelate metal pro- hepatic). oxidants. Oxidative stress can happen when generation of oxidants exceeds the natural antioxidant systems. Oxidative Bioactivity stress causes damages to DNA, RNA, lipids, proteins, and car- bohydrates and leads to different types of chronic diseases. In This refers to a specific response, biomarker, or effect observed grains, anti-oxidant potentials follow pigmented grains upon exposure to the bioactive substance. It includes tissue (tannin sorghums, black rice, brown and black sorghums, teff, uptake and the subsequent physiological response. millets, blue ) > non-pigmented grains (white-sorghum, , rice). Even though, phenolics are shown to suppress cancers in in vitro in cells and in vivo in animal models, studies Recognized Bioactive Compounds in Functional Food in human intervention are less clear. The synergetic effects are Phenolics (Polyphenolics) believed to have a role. Phenolics are also used as antimicrobial food preservatives, food colorants, and flavor imparters. Tan- Phenolics are ubiquitous in plants and more than 8000 com- nins, despite having high antioxidant activity, are antinutri- pounds are known. Dietary phenolics can be broadly divided tional and inhibit digestive enzymes and mineral absorptions. into (anthocyanins, , , , , -3-ols, condensed tannins or proanthocya- nidins, lignans, , coumarins, coumestans, and aur- Phytoestrogens one) and nonflavonoids (simple phenols, phenolic acids (hydroxybenzoates and hydroxycinnamates), and stilbenes) Phytoestrogens are nonsteroidal plant compounds with struc- (Figure 1). Flavonoids are the largest group and more than tures and biological activities similar to hormone estro- 6000 compounds have been identified. Hydrolyzable tannins gen, 17b-estradiol (Figure 3). Functional roles documented are derivatives of gallic acids. They exert deleterious effects and include: influence on growth and functioning of female and may be found at trace levels in some edible foods. Flavonoids male reproductive tissues; maintenance of skeletal and central often exist as glycosides with molecules attached often at nervous systems; cardio-protection; suppression of colon, position 3, sometimes at 5, 7, 40,30, and 50 and hydroxyls at 40, breast, and prostate cancers and skin aging; and relief from 5, and 7 on the basic structure. Flavonoids without menopausal symptoms. At low concentration, they act like are called aglycones. estrogens (agonists) and at high doses as blockers (antago- Phenolic acids and various flavonoids in whole grains and nists). Phytoestrogens are potential endocrine disrupters and bran fractions (pericarp, aleurone layer, testa, and germ) are become cytotoxic at high dose. Groups of compounds recog- extensively documented. Bran is removed during cereal grain nized as phytoestrogens are lignans, isoflavones, coumestans, milling for production of refined . Among phenolic and stilbenes. acids, ferulic acids are dominant (about 80% to 90%) in cereal grains. Sorghum is known to have unique 3- Lignans deoxyanthocyanins. Other unique phenolics documented in These are 18-carbon skeleton compounds composed of two grains are alkylresorcinols in rye, wheat, triticale, and , units with various functional groups con- avenanthramides in oats, and g-oryzanols (ferulic cid esters of nected to benzene rings (Figure 4). Secoisolariciresinol, 4 FOOD GRAINS AND WELL-BEING | Functional Foods: Overview

O OH Derivatives of simple phenol C OH Derivatives of hydroxybenzoic acid Gallic acid: R =H, R =R =R =OH R Phenol: R1=R2=R3=H 1 2 3 4 1 R1 Gentisic acid: R =R =OH, R =R =H Catechol: R1=OH, R2=R3=H 1 4 2 3 Salicylic acid: R1=OH, R2=R3=R4=H R Resorcinol: R1=R3=H, R2=OH R 3 R4 2 R2 p-(OH) Benzoic acid: R1=R2=R4=H, R3=OH Phloroglucinol: R1=H, R2=R3=OH Protocatechuic acid: R1=R4=H, R2=R3=OH OH R3 Syringic acid: R1=H, R2=R4=OCH3, R3=OH C Derivatives of hydroxycinnamic acid Vanillic acid: R1=R4=H, R3=OH, R2=OCH3 R1 O : R1=R2=R3=R4=H o- Coumaric acid: R1=OH, R2=R3=R4=H m- Coumaric acid: R1=R3=R4=H, R2=OH R R4 2 p- Coumaric acid: R1=R2=R4=H, R3=OH R3 Caffeic acid: R1=R2=H, R3=R4=OH Ferulic acid: R1=R2=H, R3= OH, R4 =OCH3 Sinapic acid: R1=H, R2=OCH3, R3=OH, R4=OCH3 Phenolic acids

Stilbene

3` 2` 4` 1 O 8 7 O 2 5` O O 6` Flavan-4-o1 6 3 OH OH 45 OH Flavonoid basic structure Flavan-3-o1 Flavonol O OH O O OH + Flavone O O HO O O O OH OH O O O O

OO O Lignan Coumarin Coumestan O

Basic structures of main class flavonoids and related structures (aurone, lignan) OH OH

HO O R OH n:0 to many OH OH OH OH O HO + O HO OH OH OH OH OH HO O Sorghum 3-deoxyanthocyanidins (Apigenindin, R=H and Luteolinidin, R=OH) OH OH Figure 1 Structures of phenolics. FOOD GRAINS AND WELL-BEING | Functional Foods: Overview 5

R1 O OH R2 N C H O OH R3 HO R Avenanthramides (more than 35 forms are identified) Alkylresorcinols (R = alkyl chain, Avenanthramide 2p, R1=R3=OH, R2=H odd carbon C15 to C27) Avenanthramide 2f, R1=R3=OH, R2=OCH3 Avenanthramide 2c, R1=R2=R3=OH O CH O C 3 OR O CH O C HO 3 O Gamma-oryzanol (ferulic acid esters, HO R = phytosterols or triterpene alcohols) Gamma-oryzanol (campesteryl ferulate) Figure 2 Structures of alkylresorcinols, avenanthramides, and gamma-oryzanols.

OH OH O OH H H

H H H H H H HO HO HO 17 beta-Estradiol Estriol Estrone Figure 3 Structures of mammalian endogenous estrogens.

HO OH O OH H H CH O CH2O CH O CH2OH 3 HO OH 3 H OH H HO CH2O O HO CH2OH OH OH OCH OCH3 3 Secoisolariciresinol diglycoside Secoisolariciresinol OH OH O H O O H CH3O O O HO O O Sesamolin HO O O Matairesinol O OH O O O H OCH3 H O O O OH Sesamol O Sesamin O H H HO OH HO O OH O Enterodiol Enterolactone

OH OH Figure 4 Structures of common lignans. 6 FOOD GRAINS AND WELL-BEING | Functional Foods: Overview matairesinol, sesamin, and sesamolin are typical examples. function and maintenance of menopausal health in women, and When two glucose molecules are attached to the hydroxyl also suppress CVD by lowering total cholesterol and LDL groups of the propanol chain of secoisolariciresinol, the com- cholesterol and raising HDL in the blood vessels. However, the pound is called secoisolariciresinol diglucoside (SDG). Lig- isoflavone content of soybean products varies with processing. nans have higher antioxidant potential than . Water- and alcohol-extracted soybean concentrate and Lignans are implicated to have potential use in hormone soybean oils have insignificant levels of isoflavones. replacement therapy, to maintain good cognitive function in postmenopausal women, and to have anticancer activities Coumestans (breast, prostate, colon, and skin cancers). They may contrib- Coumestans are less abundant than isoflavones in human ute to the reduction of hypercholesterolemia, atherosclerosis, diets. They are known to have stronger estrogenic activity 0 and diabetes. SDG is converted by bacteria in the human than isoflavones. Typical examples are coumestrol and 4 - colons to mammalian lignans enterodiol and enterolactone, methoxycoumestrol (Figure 6). Coumestrol and have which are also antioxidants. Enterodiol and enterolactone are higher binding affinities to ERb than other phytoestrogens. purported to reduce growth of cancer tumors, especially Coumestrol has been reported to inhibit bone resorption and hormone-sensitive ones. Grain sources of lignans include oil- stimulate bone mineralization by in vitro studies. Among grains, (flax, rapeseed, and sesame), whole-grain cereals (wheat, chief sources are soy sprouts, mung bean, and sunflower seeds. oats, rye, barley, and millets), and legumes (soybean). Flaxseed is the richest source of SDG and also contains other lignans Stilbenes (matairesinol, pinoresinol, lariciresinol, and isolariciresinol). Stilbenes are C6–C2–C6 compounds with –H,–OH, and –OCH3 Baked products and salad dressings fortified with flax and as substituents on their two benzene (C6) rings (Figure 7). sesame seeds can be considered as functional foods rich in Stilbenes are known to be anticarcinogenic, antioxidative, lignans antimutagenic, antitumor, and antiosteoporotic. Diets rich in resveratrol, which exists in both trans and cis isomers of the Isoflavones stilbene, are purported to prevent CVD, neurodegenerative dis- Isoflavones are often found as glycosides. Common isofla- orders such as Parkinson’s and Alzheimer’s disease, and various vones include daidzin, genistin, biochanin A, and formonone- cancers. Resveratrol has stronger antioxidant activity than propyl tin (Figure 5). The glycosides are converted to aglycones by gut gallate, vanillin, phenol, 2,6-di-tert-butyl-p-hydroxytoluene microflora. Among isoflavones, studies with genistein on (BHT), and a-tocopherol. Among grains, stilbenes are found in breast cancer cell lines show cell proliferation at low doses Fabaceae and Poaceae. Other good sources are peanuts, grape and inhibition at high concentrations. Isoflavones are also skins, and notably some sorghum varieties. recognized as mild antioxidants. Isoflavones are exclusively documented in leguminosae of which soybean is the richest source. Other sources are kidney, Phytosterols navy, pinto, red, small white, and mung beans and chickpeas, split peas, peanuts, sunflower seed, and walnut. Raw soybeans Phytosterols are natural components of human diets, are cho- can contain 1.2–4.2 mg g1 dry weight isoflavones, while high- lesterol-like and lipophilic, and comprise sterols and stanols. protein soy may contain up to 1.1–1.4 mg g1 dry weight. Stanols are hydrogenated products of sterols. Of more than Diets rich in soybeans are implicated to improve cognitive abil- 250 sterols and stanols known to exist in nature, only six ities, prevent osteoporosis and various cancers, improve immune (campesterol, campestanol, stigmasterol, sitosterol, sitostanol, and brassicasterol) are dominant in seed oils (rapeseed, soybean, corn, and sunflower oils), other grains (corn, rye,

R R1 O 2 Isoflavones R1 R2 R HO Geinstein OH OH R OH HO O Daidzin H OH Biochanin A OH OCH3 R HO Formononetin H OCH3 Stilbenes,R = H, OH or OCH3 Resveratrol Figure 5 Structures of isoflavones. Figure 7 Structures of stilbenes.

OCH O OH O 3

HO O HO O O O Coumestrol 4`-Methoxycoumestrol Figure 6 Structures of coumestrol and 40-methoxycoumestrol. FOOD GRAINS AND WELL-BEING | Functional Foods: Overview 7

R 26 18 R 20 12 20 23 21 22 21 24 11 17 16 21 22 24 26 20 23 25 26 25 19 13 20 23 25 H 24 22 27 1 9 14 15 2 27 Brassicasterol 8 27 10 Cholesterol/stanol Sitosterol/stanol 5 7 HO 3 4 6 18 R20 12 22 Sterols 11 22 21 20 23 25 17 16 21 20 23 25 26 26 19 24 H 13 24 1 9 14 15 27 2 27 8 10 Campesterol/stanol Stigmasterol/stanol 5 7 HO 3 4 6 (a) Stanols

H

C O Sitosteryl stearate O H H3CO

HO CH CHCOO Sitostany l ferulate H CH2OH O OH O HO Steryl glycoside (SG) OH O OC H CH2 O OH O HO Acylated steryl glycoside (ASG) (b) OH Figure 8 (a) Structure of plant stanols and plant sterols. (b) Conjugated structure of plant stanols and plant sterols.

wheat, barley, millets, rice, oats, and peanuts), and tree oils humans remain largely unknown. Plant sterols/stanols are (Figure 8(a)). In plant tissues, sterols and stanols can exist as also implicated to have mild anti-inflammatory effects and conjugates often esterified with fatty acids, oleic, or linoleic in are not toxic at physiological concentrations. five forms (Figure 8(b)). Plant sterols and stanols are known to attenuate absorption of low-density lipoprotein cholesterol (LDLC), a risk factor for Carotenoids premature atherosclerosis and CVD. Consumption of 2 g d1 of plant sterols or stanols as part of diet is known to lower Carotenoids are lipid-soluble tetraterpene hydrophobic LDLC plasma levels by about 10%. Consumption of low cho- compounds, which impart yellow, orange, or red colors, and lesterol and along with high stanols or sterols can found associated with lipid portions in human cells. Carotenoids reduce LDL by 20%. Statin medication along with sterols or are divided into two groups (Figure 9): (hydrocarbons) stanols is more effective in lowering LDL than doubling statin and xanthophylls (oxygenated carotenes). Carotenoids bear con- dose. Ranking toward blocking of cholesterol absorption is as jugated double bonds in their structures, which are responsible follows: free-form stanols > stanol esters > free-form sterols > for color formation and reactive oxidant stabilization. Caroten- sterol esters due to structural and metabolic reaction differ- oids are antioxidants, and functional foods processed from carot- ences toward gut microorganisms. The precise mechanisms of enoids are helpful for prevention of CVD and cancers. b-, cholesterol-lowering effect by individual compounds in a-carotene, and b-cryptoxanthin are provitamin A compounds. 8 FOOD GRAINS AND WELL-BEING | Functional Foods: Overview

H C CH3 CH3 3 H C CH Beta-carotene 3 3 Examples of carotenes H3C CH3 CH3 CH3 CH3 CH H3C CH3 3 Alpha-carotene CH H3C 3 H

H3C CH3 CH3 CH3 CH3 H C CH3 CH3 3 Beta-cryptoxanthin H3C CH3

H3C CH3 Examples of HO CH3 CH3 CH3 xanthophylls CH CH H3C OH 3 3 Zeaxanthin* H3C CH3

H3C CH3 HO CH3 CH3 CH3 CH CH H3C OH 3 3 Lutein* H3C CH3

H3C CH3 HO CH3 CH3 CH3 CH 3 CH3 O Retinyl palmitate CH H3C 3 Vitamin A O compounds

CH3 H3C

CH3 CH3 O H3C CH3 OH Retinoic acid

CH3 CH CH O CH CH CH 3 3 3 3 H3C 3 H3CCH3 H OH Retinal Retinol CH3 CH3 Figure 9 Structures of carotenoids (*not provitamin A).

Of more than 700 carotenoids identified in nature, 24 occur protective against age-related macular degeneration and cata- commonly in human foods and 40 have been detected in racts, a leading cause of eye blindness. Cereal-based lutein and humanmilk,serum,andtissues. zeaxanthin-containing functional foods processed from yellow Among grains, chief sources are yellow maize, maize, durum wheat, golden rice, einkorn, and maize bran wheat, einkorn, and golden rice. contents can include high-lutein , high-lutein cookies, high-lutein vary depending on varieties, cultivation conditions, geographic muffins, corn tortilla, corn chips, and extruded products. locations, part of plant utilized, maturity stage, food proces- sing, and storage conditions used. Heating, cooking, and mechanical disruption and the presence of /oils can enhance bioavailability of carotenoids. Carotenoid activities Omega (v)-3 Fatty Acids can be destroyed by isomerization and oxidative reactions. Lutein and zeaxanthin are not synthesized by humans. They Omega-3 fatty acids are long-chain polyunsaturated fatty acids can be supplied from grains (yellow maize, durum wheat, (PUFA) (C18-C22) commonly designated as o-3 fatty acids golden rice, and einkorn), vegetables (basil, parsley, spinach, (Figure 10). The o-3 and o-6 fatty acids are essential nutrients. kale, leek, and red pepper), yellow egg yolks, and human milk. Alpha-linolenic acids (ALA, o-3) derived from plant sources Along with their metabolite meso-zeaxanthin, both are are precursors for physiologically important longer-chain FOOD GRAINS AND WELL-BEING | Functional Foods: Overview 9

O C ALA (C18:3Δ 9,12,15) OH O

C OH EPA (C20:5Δ 5,8,11,14,17) O

C OH DHA (C22:6Δ 4,7,10,13,16,19)

Figure 10 Omega-3 fatty acids: ALA, EPA, and DHA.

PUFAs: eicosapentaenoic (EPA, o-3) and docosahexaenoic acid such best candidate because it is always consumed as whole (DHA, o-3). grain often fermented as injera with insignificant antinutrients Omega-3 fatty acids are components of cell membranes. in it and in many respects it supplies better nutrients for celiac Their documented health benefits include suppressions of patients. Other approaches to gluten-free bread quality CVD, cancer, type 2 diabetes, depression and stress, inflamma- improvements are the use of gluten-free flours and starches, tory diseases, and (6) Alzheimer’s disease. They are also bene- incorporation of nutritional ingredients, and use of structure ficial in infant nutrition for normal brain, eye, and mammalian modifier additives and processing technologies that will nervous system development and function. Omega-3 fatty change the allergenic . acids are available as supplements from pharmaceuticals. Other bioactive compounds to be noted include tocols However, consumers prefer o-3 fatty acids from diets. In this (tocopherols and ) from cereal germ and aleurone respect, there is high opportunity for o-3 fatty acid-containing layers; betaine and from wheat, barley and rye germ, functional foods. The main source of ALA is flaxseed. Other and brans; and benzoxazinoids from whole-grain wheat and sources are canola, soybean oils, and walnuts. In flaxseed, rye. Some bioactive compounds known for their antinutri- bioavailability of ALA is as follows: oil > milled > whole tional effects tend to portray beneficial effects under specific flaxseed. Despite fish oil being a major source of EPA and conditions. They include glucosinolates from rapeseed, phytic DHA, it is sensitive to autoxidation, and there is also a possi- acids from germ and aleurone layers of grains, and bility for methyl mercury toxicity since fish has potential for (hemagglutinins) from legumes and whole cereal grains. contamination with this toxin. Where consumption of fish oil is limited and methyl mercury toxicity is a possibility, EPA and DHA are required to be supplied from ALA even though con- Conclusions version of ALA to EPA and DHA is known to be inefficient. Baked foods like bread and injera and various cereal grain Opportunities for grain-based functional foods are high snacks processed by incorporating flaxseed oils and/or milled because grains are sources of many bioactive compounds that flaxseed flours are an alternative way of supplying o-3 are located in specific anatomical structures. However, bio- fatty acids. availability can be influenced by many factors including forms of existence, processing technology, and food matrices that prevail during consumption. Functional foods are recog- Gluten-Free Foods nized to be consumed as varied regular diets. However, the absence of a definition that has received global consensus In some genetically predisposed individuals, gluten proteins potentially poses various risks such as inaccurate health claims, from wheat, rye, barley, and triticale when ingested will lead to adverse reactions, poor quality control during manufacturing, celiac disease (CD). Oats are also not considered free, because allergic reactions, and carcinogenicity. Novel foods in particu- of potential contamination and the possibility that some peo- lar may pose unprecedented risks because they do not have a ple who are intolerant to gluten are not immune to it. CD long history as diets to populations of different genetic back- involves interactions between genetic susceptibility (HLA- ground. A distinction between novel and functional foods may DQ2 and HLA-DQ8 alleles), gluten proteins, and an help to reduce such effects. Misuse of functional foods can immunologic response that causes small intestinal mucosal lead to adverse effects such as anti-nutritional, thyroid toxicity, damage characterized by complete loss of absorptive villi to drug interactions, allergic reactions and geno-toxicity/ maldigestion and malabsorption of nutrients. Such effects lead carcinogenicity. to chronic diseases like skin lesions, anemia, diarrhea, weight A given diet is believed to bear more than 25000 bioactive loss, osteoporosis, fatigue, infertility, and cancer. About 1% of constituents. Minimum dietary intake that would lead to desir- the world population is estimated to be gluten-intolerant. able health effect and maximum intake to avoid adverse effects There is no drug for CD, and the remedy is a complete adher- are yet not available for most bioactive compounds. A distinc- ence to a gluten-free diet (GFD). The Codex Alimentarius Com- tion is yet to be clearly established for most bioactive com- mission and FDA have set standards for GFD to be pounds whether a desirable outcome is caused by a single <20 mg kg 1 gluten. Gluten proteins are vital for production compound or by synergic effects. Since they are consumed as of aerated baked products to which consumers are attracted. regular varied diets for health promotion, designing functional The use of baked products from gluten-free cereal grains (teff, foods for synergic effects of bioactive compounds seems ben- maize, rice, sorghum, and the millets) particularly those pro- eficial. While designing for an optimum supply for those cessed from whole grains is a remedy for CD. Teff grain is one health effects is established, caution is also required not to 10 FOOD GRAINS AND WELL-BEING | Functional Foods: Overview affect other components used to be served in a given regular Diseases: Celiac Disease; Cereal Allergens; The Gluten-Free Diet; diet. With an accurate definition in place, functional foods can The Basics: Grain: Morphology of Internal Structure. be better regulated to improve health and well-being.

Exercises for Revision Further Reading

Provide three features that you think useful to describe Bagchi D (ed.) (2014) Nutraceutical and Functional Food Regulations in the United • States and Around the World. NW, USA: Elsevier Inc. functional foods. Capriles VD and Areˆas JAG (2014) Novel approaches in gluten-free bread making: • Describe how functional foods are different from dietary interface between food science, nutrition, and health. Comp. Rev. Food Sci. Food supplements, prescribed drugs, traditional medicines, and Saf. 13: 871–890. nutraceuticals. Doyon M and Labrecque J (2008) Functional foods: a conceptual definition. Br. Food J. List various grain-based bioactive compounds. 110(11): 1133–1149. • Dykes L and Rooney LW (2007) Phenolic compounds in cereal grains and their health • Provide factors that may influence bioaccessibility, bio- benefits. Cereal Foods World 52: 105–111. availability, and bioactivity of bioactive compounds. Fraga CG (ed.) (2010) Plant Phenolics and Human Health: , Nutrition, and • List potential safe diets for celiac patients. Pharmacology. Hoboken, NJ, USA: John Wiley & Sons, Inc. Name indigenous foods consumed in your communities Gogus U and Smith C (2010) n-3 Omega fatty acids: a review of current knowledge. Int. • J. Food Sci. Technol. 45: 417–436. believed to have health-promoting effects. Gylling H, Plat J, Turley S, Ginsberg HN, Ellega˚rd L, Jessup W, Jones PJ, Lu¨tjohann D, Maerz W, Masana L, Silbernagel G, Staels B, Bore´n J, Catapano AL, De Backer G, Deanfield J, Descamps OS, Kovanen PT, Riccardi G, Tokgo¨zoglu L, and Exercises for Readers to Explore the Topic Further Chapman MJ (2014) Plant sterols and plant stanols in the management of dyslipidaemia and prevention of cardiovascular disease. Atherosclerosis 232: 346–360. • Explore the possibility of extending the earlier lists of bio- Hasler CM and Brown AC (2009) Position of the American dietetic association: active compounds in various grains. functional foods. J. Am. Diet. Assoc. 109: 735–746. • What metabolites are produced from the partial degrada- Howlett J (2008) Functional Foods: From Science to Health and Claims. Belgium: ILSI tion of some of the bioactives listed? Find out if these are Europe. Malla S, Hobbs J, and Sogah EK, (2013) Functional Foods and Natural Health Products still active. Regulations in Canada and Around the World: Nutrition Labels and Health Claims. • Investigate what innovative processing technologies might Report Prepared for the Canadian Agricultural Innovation and Regulation Network provide optimum utilization of grain bioactive com- (CAIRN), Canada pounds. Could these technologies also ensure that food Mohamed S (2014) Functional foods against metabolic syndrome (obesity, diabetes, safety issues are addressed because bioactive compounds hypertension and dyslipidemia) and cardiovascular disease. Trend Food Sci. Technol. 35: 114–128. are located in unique grain anatomical parts? Ndolo VU and Beta T (2014) Comparative studies on composition and distribution of • Research the possibilities in to enhance the phenolic acids in cereal grain botanical fractions. Cereal Chem. 91(5): 522–530. presence and availability of bioactives. Peterson J, Dwyer J, Adlercreutz H, Scalbert A, Jacques P, and McCullough MJ (2010) Investigate the possible exploitation of indigenous foods Dietary lignans: physiology and potential for cardiovascular disease risk reduction. • Nutr. Rev. 68(10): 571–603. relevant to your region. Their consumption as safe diets has Sajilata MG, Singhal RS, and Kamat MY (2008) The carotenoid pigment zeaxanthin—a been known for ages, so their potential to grow in the review. Comp. Rev. Food Sci. Food Saf. 7: 29–49. functional foods spectrum should be considerable. Taylor JRN, Belton PS, Beta T, and Duodu KG (2014) Review: Increasing the utilization of sorghum, millets and pseudocereals: Developments in the science of their phenolic , biofortification and protein functionality. J. Cereal Sci. See also: Appendix 3: Grains, Foods, and Ingredients Suiting 59: 257–275. Gluten-Free Diets for Celiac Disease; Bioactives and Toxins: Bioactives: Antioxidants; Bioactive Compounds in Wheat Bran; The Antinutritional Components of Grains; : Glycemic Index, Glycemic Load, and Their Health Benefits; Grains other than Cereals: Non-starch Polysaccharides; Food Grains and the Consumer: Cultural Differences in Processing and Consumption; Relevant Websites Fortification of Grain-Based Foods; Genetically Modified Grains and the Consumer; Grains and Health: Misinformation and Misconceptions; http://www.biomedcentral.com/content/supplementary/1475-2891-9-3-S1.PDF – University of Oslo. Grains and Health; Labelling of Grain-Based Foods; Food Grains and http://www.glnc.org.au/wp-content/themes/glnctheme/images/home.png Well-being: Functional Foods: Dietary Fibers, Prebiotics, Probiotics, http://www.google.co.bw/url? and Synbiotics; Food Grains: Intolerance, Allergy and http://www.nutritionj.com/content/9/1/3.