Caballero B. (ed.) Encyclopaedia of Food Science, Food Technology and Nutrition. Ten-Volume Set

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1.0023 The intake of nutrient is below the desirable level

in the diet of a significant number of people.

0024 The food used to supply the nutrient is likely to be

consumed in quantities that will make a significant

contribution to the diet of the population in need.

0025 The addition of nutrient is not likely to create an

imbalance of essential nutrients.

0026 The nutrient added is stable under proper condi-

tions of storage.

0027 The nutrient is physiologically available from the

food.

0028 There is reasonable assurance against excessive

intake to a level of toxicity.

0029 Various studies have confirmed that fortification of

BC foods is appropriate and has contributed signifi-

cantly to improving overall nutrition. Fortification of

flour and other grain-based foods with folic acid

became a requirement in the USA in 1998 because

of evidence that it may help prevent neural tube

defects.

0030 Many nutritionists consider eating breakfast regu-

larly as one of the important health habits associated

with subsequent favorable health status and reduced

mortality. Breakfast consumers were found to do

significantly more work in the morning than those

who did not. Children and the elderly (above 65

years old) are the largest consumers of BC. Half of

the school-age children in the USA prepare their own

breakfast because most of their mothers work outside

their homes. These groups are more likely to skip

breakfast. Studies have indeed confirmed that BC

consumers are likely to skip fewer breakfasts and

that they obtain higher levels of vitamins and min-

erals than others. Most BC also contain up to 5 g of

dietary fiber per serving. Some high-fiber products

can provide 10 g or more of fiber and thus help

consumers to improve their dietary fiber intake and

to meet recommendations of 25–30 g daily dietary

fiber intake. Oat-based BC containing sufficient

beta-glucan soluble fiber to provide 3 g or more of

that substance daily, or other BC containing suffi-

cient psyllium to provide 7 g of soluble fiber from

that source daily, have been shown to decrease

blood cholesterol by a small but significant amount

and in the USA may carry label health claims to that

effect.

0031 BC, with few exceptions, are not high in protein.

The protein in some cereals, such as gun-puffed or

flaked products, may have little or no biological

value, due to excessive Maillard browning. Some

RTE cereals may also be high in sugar and/or salt

(sodium) and may contain added saturated fat.

Nevertheless, BC with milk and fruit make an inex-

pensive, nutritious, and easy-to-prepare breakfast.

(See Browning: Nonenzymatic; Dietary Fiber: Prop-

erties and Sources.)

Packaging, Storage, and Spoilage

0032The BC industry, over the years, has developed effi-

cient processing, packaging, storage, and shipping

technologies to supply consumers with cereal foods

that routinely have 6 months’ or longer shelf-life. It is

indeed quite a feat to have such an array of vitamins

and minerals, which often interact with each other, in

a highly processed food and yet end up with a whole-

some product with a desirable flavor and texture. In

the process, the industry has developed novel tech-

niques for vitamin preservation and for the incorpor-

ation of antioxidants directly or via the packaging

material. BC packages not only protect the product

against moisture, oxygen, and insects during shipping

and storage, but also provide attractive consumer

appeal at the point of purchase. The industry has

accomplished this by following good manufacturing

practices and other quality control measures, and by

instituting Hazard Analysis and Critical Control

Point (HACCP) systems for food safety purposes.

Computer control of processing and attention to

environmental issues also characterize most BC

manufacturing operations, and certainly the newer

ones.

Future Developments

0033The Nutritional Labeling and Education Act of 1990

and subsequent amendments in the USA undoubtedly

contributed to the reevaluation of product develop-

ment, marketing, and advertising strategies by the BC

industry as a result of stricter control of nutrient

claims, ingredient listing, and other label data.

Among other moves, the BC industry has endeavored

to develop new products made from whole grains that

are also low in fat, sugar, and salt (sodium). Encour-

agement was provided by FDA approval of a health

claim being made for products containing one or

more whole grains as a majority constituent. Other

product developments or modifications of BC in the

USA or elsewhere are likely to be influenced by such

regulatory developments as well as by advances in

technology or nutritional knowledge.

See also: Barley; Browning: Nonenzymatic; Calcium:

Physiology; Dietary Fiber: Properties and Sources; Food

Fortification; Iron: Physiology; Magnesium; Maize;

Oats; Retinol: Physiology; Rice; Wheat: The Crop; Grain

Structure of Wheat and Wheat-based Products; Zinc:

Physiology

1026 CEREALS/Breakfast Cereals

Further Reading

Fast RB (1999) Origins of the US breakfast cereal industry.

Cereal Foods World 44: 394–397.

Fast RB and Caldwell EF (eds) (2000) Breakfast Cereals and

How They Are Made, 2nd edn. St Paul, Minnesota:

American Association of Cereal Chemists.

Hoseney RC (1994) Principles of Cereal Science and

Technology, 2nd edn. St Paul, Minnesota: American

Association of Cereal Chemists.

Slade L and Levine H (1991) Beyond water activity: recent

advances based on an alternative approach to the assess-

ment of food quality and safety. Critical Reviews in Food

Science and Nutrition 30: 115–360.

Dietary Importance

S O Serna Saldivar, Instituto Tecnologico y de

Estudios Superiores de Monterrey, Monterrey N.L.,

Mexico

Introduction

0001 Cereal-based foods are by far the major source of

energy, protein, B vitamins, and minerals for the

world population. In most countries, diets have a

single cereal as the primary staple. The most widely

used cereals are rice, wheat, and maize, which pro-

vide 93% of the total cereal calories. These grains

constitute the main staple for Asia, Europe, and

America, respectively. In Africa and India, sorghum

and millets are widely grown and consumed. (See

Maize; Rice; Sorghum; Wheat: The Crop.)

0002 According to the Food and Agriculture Organiza-

tion (FAO), the amount and proportion of food

energy and protein provided by cereals in human

diets in 1997 were 1384 kcal (5796 kJ), nearly 50%

of the average per capita caloric intake. Likewise,

cereals provided 33.8 g of protein of the total esti-

mated daily intake of 73.9 g of protein. Cereal

grains are considered primarily as caloric or starchy

foods and, more recently, as an important source of

dietary fiber. However, their protein quality, espe-

cially for infants, is marginal. In developing coun-

tries, cereals are usually consumed with legumes

and pulses, thus significantly increasing protein

intake and, more importantly, complementing

their essential amino acid composition. Protein and/

or calorie malnutrition (i.e., marasmus, kwashiorkor)

is prevalent among groups of people who have

inadequate food intake or rely solely upon cereals

and/or starchy roots as their source of protein.

(See Energy: Measurement of Food Energy; Kwashi-

orkor; Malnutrition: The Problem of Malnutrition;

Marasmus.)

0003Plant breeders have developed maize, sorghum,

and barley genotypes with high lysine, which results

in an improved protein quality and nutritional value.

A high lysine and tryptophan corn, called quality

protein maize, with satisfactory grain yield and struc-

ture is being commercially grown in different places

around the world (Brazil, China, Ghana, and other

African countries). (See Maize.)

Carbohydrates

0004Starch is the most abundant carbohydrate in cereals

and the main contributor of calories (Table 1). It

is composed of molecules of branched amylopectin

and linear amylose. Most cereals contain 70–75%-

amylopectin. Waxy maize, rice, and sorghum contain

more than 95% amylopectin. Most food processes

partially or totally gelatinize the starch granules,

making the molecules more prone to amylase

hydrolysis. (See Starch: Structure, Properties, and

Determination.)

0005Starch is highly digestible by the human digestive

system. Practically all starch disappears in the gastro-

intestinal tract. A small portion of the starch (1–5%)

resists enzymatic hydrolysis when cereal foods are

thermally abused. This residual starch can be quanti-

fied in the soluble dietary fiber residue and is highly

susceptible to fermentation in the large intestine. (See

Starch: Resistant Starch.)

0006Other factors that can decrease starch digestibility

are excessive amounts of fiber and enzyme inhibitors

(i.e., tannins). The digestible energy of cereals is nega-

tively and positively related to the grain’s fiber and

lipid contents, respectively. Refined grains contain

more digestible energy than whole products

(Table 1). As a result of its high fat and low fiber

content, maize contains high quantities of digestible

energy.

0007Cereals contain small quantities of soluble carbo-

hydrates (i.e., glucose, fructose, maltose, sucrose);

they are therefore suitable foods for diabetics. Highly

refined cereals have a higher glycemic index than

whole-grain products. (See Glucose: Glucose Toler-

ance and the Glycemic (Glycaemic) Index.)

0008Whole cereal grains are considered a rich source of

fiber (Table 1). However, foods from grains have

marked differences in the amount and type of dietary

fiber. Fiber components are concentrated in the outer

tissue of the kernel (pericarp). The dietary fiber con-

tent in cereal-based food varies greatly, depending on

the extent of milling. Refined flours lose most of their

fiber during decortication and milling. All cereals are

CEREALS/Dietary Importance 1027

tbl0001 Table 1 Nutrient composition of cereal grains

Proximate composition Dietary fiber

Cereal Protein (%) Crude fat (%) Crude fiber (%) Ash (%) NFE (%) Starch (%) Digestible energy Total (%) Soluble (%)

kcal kg

1

kJ kg

1

Wheat

Hard 14.4 2.3 2.9 1.9 78.5 64 3 865 16 181 12.1 1.7

11.5–17 1.8–2.8 2.8–3 1.8–2 75.2–82.1

Soft 9.9 2.8 2.7 1.7 82.9 69 3 865 16 181 12.1 1.7

8–12 2.6–2.9 2.5–2.8 1.8–1.9 80.4–85.1

Durum 13.2 2.8 2.8 2 79.2 70.2 4 056 16 981 12.1 1.7

12–15.6 1.8–3.8 2.4–3.1 1.8–2.1 75.4–82

Rice

Paddy 7.5 2.4 10.2 4.7 75.2 2 821 11 810

6.7–9 1.7–2.7 8.4–12.1 3.4–6 70.2–79.8

Brown 9.2 2.5 0.9 1.5 85.9 77.2 4 321 18 091 3.7 0.9

8.3–10.1 1.8–3.3 0.7–1.2 1.2–1.8 83.6–88

Milled 7.8 0.5 0.4 0.6 90.7 90.2 3 938 16 488 1.3 0.4

7.3–8.3 0.3–0.6 0.2–0.6 0.3–0.9 89.6–91.9

Maize

Dent 9.1 4.4 3 1.7 81.8 71.8 4 056 16 982 12.8 1.1

8.1–11.5 3.9–5.8 2.4–3.5 1.4–2 77.2–84.2

Flinty 11.1 4.9 2.2 1.7 80.1 4 056 16 982

9.5–12.8 4–5.8 1.6–2.8 1.4–2 76.6–83.5

Popcorn 12.1 4.6 2.3 1.8 79.2 62.3 13.1 0.4

11–13.2 4–5.3 2.2–2.4 1.6–1.9 77.2–81.2

Sweet 13.2 4.6 2.7 2.3 77 54.1 4 145 17 354 9.4 1.2

12.1–14.2 3.7–9 2.2–3.2 2–2.7 70.9–80.1

Barley 11.5 2.2 5.6 2.9 77.8 58.5 3 543 14 833 15.4 3.9

7.5–15.6 1.8–2.6 5.3–5.9 2.6–3.1 72.8–82.8

Rye 13.4 1.8 2.1 2 80.7 68.3 3 794 15 885 16.1 3.8

12.6–14.5 1.6–2.2 1.6–2.6 1.7–2.2 78.5–82.5

Oats

Whole 17.1 6.4 11.3 3.2 62 52.8 3 058 12 803

12.4–24.4 4.5–10.3 10.4–14.3 2.9–3.4 47.6–69.8

Groats 16.9 7.4 1.6 2.1 72 65 4 316 18 070 12.5 6.6

13.8–22.5 5.9–8.4 1–3.3 1.9–2.4 65.2–77.4

Sorghum 11 3.2 2.7 1.8 81.3 73.8 3 880 16 245 11.8 1

7.3–15.6 0.5–5.2 1.2–6.6 1.1–4.5 68.1–89.9

Millets

Pearl 14.5 5.1 2 2 76.4 60.5 2 822 7.0 0.6

8.6–19.4 1.5–6.8 1.4–7.3 1.6–3.6 62.9–86.9

Finger 8 1.5 3 3 84.5 59

6–10.9 1–4.6 2–6.8 2.3–3.9 73.8–88.7

Italian 11.7 3.9 7 3 74.2 59.1 3 395

6–14 1.2–5.2 2.6–8.6 1.5–3.6 68.3–88.7

Proso 11 3.5 9 3.6 72.9 56.1 3 636

6.4–12.8 2.9–4.9 4.6–12 1.4–5 65.3–84.7

Japanese 11.8 4.9 14.3 4.9 64.1 62

11.2–12.7 2.5–6.3 13.9–14.7 4.7–5 61.3–68

Fonio 8.7 2.8 8 3.8 76.6

5.1–10.4 2.1–5.2 4.6–11.3 1.8–6 67.1–86.4

Kodo 10.4 3.7 9.7 3.6 72.6 72

6.2–13.1 3.2–4.9 8.4–11 3–4.1 66.9–79.2

Teff 10.9 2.4 2.4 2.2 82.1

7.9–12.6 2.3–2.5

All values are expressed on a dry-matter basis. Protein conversion factors: for wheat, 5.7; rice, 5.95; other cereals, 6.25; NFE ¼nitrogen-free extract.

1028 CEREALS/Dietary Importance

considered a rich source of insoluble dietary fiber

(i.e., cellulose, insoluble hemicellulose). Insoluble

fiber binds water, speeds up intestinal transit and

binds some carcinogens. Epidemiological evidence

has related a high-fiber diets to a lower incidence of

diabetes, obesity, and diverticular disease. A high

dietary fiber consumption benefits diabetics because

of the reduced diffusion of glucose in the intestinal

mucosa and the diminished insulin secretion rate. (See

Dietary Fiber: Properties and Sources; Determin-

ation; Effects of Fiber on Absorption.)

0009 Oats, barley, and rye are considered goods sources

of soluble dietary fiber (i.e., pentosans, b-glucans,

soluble hemicellulose), which has been associated

with increased excretion of bile salts and dietary

cholesterol, thus lowering blood cholesterol levels.

Protein

0010 Cereal grains provided 45% of our total protein

intake in 1997. Genotype, environment, and growing

conditions affect the amount of protein in the kernel.

In general, brown rice and oats contain the lowest

and highest protein content, respectively (Table 1).

Protein quality is mostly dictated by the amino acid

profile and digestibility (Table 2). The apparent pro-

tein digestibilities in cereals range from 80% to 90%.

Sorghum (especially kernels with condensed tannins),

whole barley, rye, and oats are consistently lower in

digestibility than other cereals. Milling, decortica-

tion, fermentation, and germination all increase pro-

tein digestibilities because of the removal of fiber and

the enzymatic breakdown of proteins. (See Protein:

Chemistry; Quality.)

0011 The storage protein in cereals (prolamines) con-

tains small amounts of essential amino acids, espe-

cially lysine. The albumin and globulin proteins,

mainly located in the germ, contain the best essential

amino acid profile. High-lysine cultivars of maize,

sorghum, and barley are genetically modified to con-

tain lower amounts of prolamines and higher

amounts of the other protein fractions. Thus, they

have a more balanced protein. (See Amino Acids:

Metabolism; Protein: Quality.)

0012 For all cereals, the most limiting amino acid is

lysine. Oats, rice, rye, barley, and the high-lysine

cultivars contain a more favorable essential amino

acid composition or amino acid score than the rest

of the cereals (Table 2). Lysine deficiency is observed

particularly in postweaned infants who suffer from

kwashiorkor and rely on cereals and/or starchy tubers

as the only food source. The supplementation of

cereal-based foods with small quantities of legumes

or animal foods improves protein intake and protein

quality. The next most limiting amino acids for maize

and the rest of the cereals are tryptophan and

threonine, respectively.

0013Decortication or milling partially or totally re-

moves the pericarp and germ tissues, therefore im-

proving the digestibility and reducing the lysine

level. Malting improves protein quality due to enzym-

atic degradation of proteins. Fermentation improves

protein quality via improved digestibility and de-novo

synthesis of lysine by the fermenting biomass.

Lipids

0014Lipids are relatively minor constituents in cereal

grains (Table 1). However, cereal lipids are rich in

the essential fatty acid, linoleic acid (18:2 D 9, 12;

30–60% of total fatty acids), and practically devoid

of saturated fatty acids. Cereals contain trace

quantities of phytosterols; they do not have any

cholesterol. Cereals with yellow endosperm (i.e.,

yellow corn, yellow sorghum, durum wheat) contain

some provitamin A activity (b-carotenes). Various

types of tocopherols are responsible for the vitamin

E activity of cereal grains. Degermination of cereal

grains greatly reduces the content of lipids and

tocopherols.

Minerals and Vitamins

0015The pericarp, germ, and aleurone layer are rich

in vitamins and minerals. Refined cereal products

therefore lose part of these important nutrients. The

enrichment of cereal-based foods is aimed toward the

replacement of minerals (Fe and recently Zn) and

vitamins (thiamin, riboflavin, niacin, and recently

folic acid) lost during milling. In some countries, the

enrichment of cereal-based foods is required by law.

(See Anemia (Anaemia): Iron-deficiency Anemia;

Folic Acid: Properties and Determination; Iron: Prop-

erties and Determination; Niacin: Properties and

Determination; Riboflavin: Properties and Determin-

ation; Thiamin: Properties and Determination; Zinc:

Properties and Determination; .)

0016In general, cereals are a very poor source of calcium,

except for finger millet and teff (Table 3). Some food

processes, such as nixtamalization of maize for tortilla

production, greatly increase calcium. The bioavail-

ability of this mineral in tortillas is high. (See Tor-

tillas.)

0017Phosphorus is the most abundant mineral (Table 3).

Unfortunately, its availability is questionable because

it is complexed with phytic acid. The phytic acid has

the property of binding strongly with cations, thus

decreasing their bioavailability. Phytic acid decreases

significantly during fermentation, due to activation of

phytases. These processes considerably improve the

CEREALS/Dietary Importance 1029

tbl0002 Table 2 Amino acid composition of cereal grains

Amino acid

(gper100 g of protein)

Wheat Maize Rice Sorghum Barley Rye Oats Groats Millets

Hard Durum Normal High-lysine Brown Milled Normal High-lysine Pearl Finger Proso Japanese Italian Kodo Teff

Essential

Phenylalanine 4.6 4.1 4.8 4.3 5.2 5.2 5.1 4.9 5.2 5 5.4 4.2 5.2 5.2 5.2 5.9 5.5 5.8 5.7

Histidine 2 1.9 2.9 3.8 2.5 2.5 2.1 2.3 2.1 2.4 2.4 2.2 2.2 2.2 2.2 1.9 2.9 1.8 3.2

Isoleucine 3 3.6 3.6 3.4 4.1 4.5 4.1 3.9 3.6 3.7 4.2 3.9 4.4 4.4 4.6 4.5 5.9 3.1 4

Leucine 6.3 7 12.4 9 8.6 8.1 14.2 12.3 6.6 6.4 7.5 7.4 11 9.5 12.9 11.5 14.1 8.6 8.5

Lysine 2.3 2.2 2.7 4.3 4.1 3.9 2.1 3 3.5 3.5 4.2 4.2 2.9 2.9 2.2 1.7 2.2 3.2 3.5

Methionine 1.2 0.9 1.9 2.1 2.4 1.7 1 1.6 2.2 1.6 2.3 2.5 2 3.1 2 1.8 2.6 1.7 4.1

Threonine 2.4 2.9 3.5 3.9 4 3.7 3.3 3.3 3.2 3.1 3.3 3.3 3.9 4.2 3.3 2.7 4.3 2.9 4.3

Tryptophan 1.5 0.5 0.9 1.4 1.3 1 0.9 1.5 0.8 1.3 2.3 1.5 0.9 1 1.4 0.8 1.4

Valine 3.6 4.6 4.9 5.6 5.8 6.7 5.4 5.1 5 4.9 5.8 5.3 5.7 6.6 5.1 6.1 5.1 4.2 5.5

Nonessential

Aspartic acid 4.7 4.7 6.4 7.7 9.3 9.8 6.4 7.5 6 6.7 9.2 8.9 8.6 6.5 5.7 6.1 6.9 6.3 6.6

Glutamic 30.3 32.3 19.2 17.1 17.3 19.3 20.6 20.1 25.5 24.7 21.6 23.9 20.7 20.3 20.4 23.9 18.8 23.1 24.8

Alanine 3.1 4.8 7.7 6.3 5.8 5.8 8.6 8.4 2.1 2.4 5.1 5 8.5 6.2 10.7 9.3 8.9 5.5 5.7

Arginine 4 3.5 4.8 6.9 9.5 8.8 3.5 4.5 4.6 5.9 6.4 6.9 5.3 4.5 3.2 3.6 2.8 3.6 5

Cysteine 2.8 1.4 2.3 2.2 1.6 1.5 1.8 2 1.7 1.6 2.1 2.6 1.6 2.7 1.4 1 0.9

Glycine 3.8 6.5 3.8 5 4.8 4.8 2.9 3.5 3.9 4 5.1 4.9 3.3 4 2.2 2.3 2.9 3.8 3.8

Proline 10.1 13.4 8.2 9.1 5 4 7.9 7.6 11.6 9.1 5.7 4.7 6.6 7 7.2 10.1 10.6 7.2 5.5

Serine 4.2 5.7 4.6 4.7 5.3 4.3 4.1 4.2 3.8 4.1 4 4.2 4.9 5.1 6.3 5.6 5.8 4.1 5.2

Tyrosine 2.7 2 4.2 3.5 4.2 5 3.2 4.2 2.8 2.6 2.6 3.1 3.2 3.6 2.4 2.4 2.6 3.8 3.9

Amino acid score (%) 42.3 40.4 49.6 79 75.4 71.7 38.6 55.1 64.3 64.3 77.2 77.2 53.3 53.3 40.4 31.2 40.4 58.8 64.3

Protein digestibility 89.8 87.9 88.2 88.9 88.5 89 85.9 88.9 84.9 86.7 86.2 90.6 89 89.9 89.8

Essential amino acid requirements for infants (g per 100 g of protein): lysine, 5.44; methionine and cysteine, 3.52; threonine, 4; isoleucine, 4; leucine, 7.04; phenylalanine and tyrosine, 6.08; histamine, 1.4; tryptophan,

0.96; tyrosine and cysteine are not essential amino acids, but they can spare the requirements for phenylalanine and methionine, respectively.

bioavailability of minerals. (See Phytic Acid: Proper-

ties and Determination.)

0018 Cereals are considered a good source of potassium

and are practically devoid of sodium. Whole grains

provide a significant amount of magnesium, iron,

zinc, and copper, which is reduced by degermination,

decortication, and milling.

0019 Cereals are also considered an important source of

B vitamins (except B

or cobalamin), but dried-

matured grains do not contain vitamin C. The B

vitamins are concentrated in the aleurone layer. Beri-

beri (a thiamin-deficiency disease), endemic in eastern

and southern Asia, is prevalent among people who

consume milled rice. Milled rice contains about 10%

of the thiamin of brown rice (Table 3). (See Beriberi.)

0020 Niacin is found in a free and bound form and can

be synthesized from tryptophan. The alkali treatment

of maize for tortilla production considerably im-

proves niacin bioavailability because the glucosidic

bond that renders it unavailable is alkali-labile.

Niacin deficiency produces pellagra, which causes

dermatitis, diarrhea, and dementia and has been

prevalent in regions of Southern Africa where people

rely on maize as the main food source. (See Niacin:

Properties and Determination; Pellagra.)

Toxins and Contaminants

Naturally Occurring Antinutritional Compounds

0021 All cereals contain relatively high levels of phytic acid,

which binds minerals (cations). Germination and/or

fermentation improves mineral bioavailability due to

the enzymatic activity of phytases and bacteria.

0022 Brown sorghums contain condensed tannins in

their testa. The brown sorghums are grown to avoid

bird damage and grain deterioration due to sprouting

and weathering. The tannins bind hydrophobically

with, and precipitate, proteins in food systems, thus

lowering digestibility. Germination and the treatment

of grain with calcium oxide (CaO), potassium carbon-

ate (K

), ammonium bicarbonate (NH

HCO

or sodium bicarbonate (NaHCO

) detoxifies the

grain and consequently improves its nutritional

value. In Tanzania, Magadi soda is used to detoxify

brown sorghum in small villages. (See Sorghum;

Tannins and Polyphenols.)

0023 A higher incidence of goiter among pearl millet

eaters in West Africa (Sudan) has been attributed to

a goitrogenic compound. The goitrogen has been

identified as a thioamide, mainly found in the bran

and endosperm. Heat treatment (autoclaving) appar-

ently detoxifies the grain. Trypsin inhibitors and

saponins have been isolated in pearl millet. (See Goi-

trogens and Antithyroid Compounds.)

Contaminants

0024Cereal grains are susceptible to mold attack, espe-

cially when storage conditions are inappropriate.

Some molds produce many toxic compounds that

can severely affect human health or even cause

death. The most important mycotoxin is that pro-

duced by Aspergillus flavus. Aflatoxins have been

found in most cereal grains, but they are most preva-

lent in maize. The toxin is a potent hepatocarcinogen

at concentrations in parts per billion. The most preva-

lent aflatoxins in cereal grains are B

and B

. For

optimum growth and aflatoxin production, the

mold requires a relative humidity of 85% and a tem-

perature range of 27–30



C and at least 17.5% mois-

ture content in the cereal grain. The alkali treatment

of maize for tortilla production significantly reduces

the amount of aflatoxins. Most of the aflatoxins end

up in the steep and wash waters. (See Mycotoxins:

Occurrence and Determination; Spoilage: Molds in

Spoilage; Tortillas.)

0025Ochratoxins are produced predominantly by the

storage fungus, Aspergillus ochraceus. Toxicity is

characterized by nephropathy, mild degeneration of

the liver, and enteritis in swine, poultry, and humans.

Endemic ochratoxicosis has been observed in the

Balkans (Bulgaria, Yugoslavia, Romania) since 1950.

0026Species of Fusarium produce toxins that affect

humans and animals. An example is scab wheat and

barley contaminated with F. graminearum. The prep-

aration of bakery products with contaminated grain

causes vomiting and inebriation in humans. Zerale-

none, another Fusarium toxin, is the most frequent

mycotoxin in cereal grains. It is mainly found in

maize. Zeralenone produces vomiting in monogas-

trics, and diarrhea, hemorrhage, swelling of genitals,

and infertility in swine. The fumonisins are the most

recently discovered family of Fusarium toxins. Their

isolation was prompted by the death of horses from

encephalomalacia and esophageal cancer. Recent

epidemiological data have related consumption of

fumonisin-contaminated maize with esophageal

cancer in humans.

0027Ergot(Clavicepspurpurea)isafungusthatinfectsrye

and, less often, wheat, barley, and oats. Honey disease

of millet and sorghum is caused by ergot. The toxicity

of ergot has been documented for several centuries.

Epidemics of poisonings have occurred in North Amer-

ica, the UK, Europe, Russia, and other places. Ergot

toxicity produces a disease commonly called Saint

Anthony’s Fire, which produces gangrenous necrosis,

hallucinations, and convulsions. The fungi produce

toxicity via the formation of alkaloids (ergotamine,

ergotoxine, and ergometrine). Growth of the fungus

is promoted by moist, warm climatic conditions.

CEREALS/Dietary Importance 1031

tbl0003 Table 3 Mineral and vitamin composition of cereal grains

Nutrients Wheat Maize Rice Sorghum Barley Rye Oats Groats Millets

Hard Durum Brown Milled Pearl Finger Proso Italian Kodo Teff Fonio

Minerals

Ca (%) 0.03 0.04 0.03 0.03 0.02 0.04 0.04 0.05 0.11 0.08 0.01 0.33 0.01 0.01 0.01 0.17 0.03

P (%) 0.35 0.51 0.29 0.25 0.12 0.35 0.56 0.36 0.38 0.51 0.35 0.24 0.15 0.31 0.32 0.45 0.18

Phytic acid (%) 0.97 0.71 0.56 0.77 1.06 0.97 1.80 0.32

K (%) 0.36 0.49 0.37 0.17 0.10 0.38 0.50 0.47 0.47 0.44 0.44 0.43 0.21 0.27 0.17 0.31 0.16

Na (%) 0.04 0.03 0.03 0.00 0.05 0.02 0.01 0.02 0.01 0.02 0.01 0.01 0.01 0.02 0.02

Mg (%) 0.14 0.17 0.14 0.19 0.03 0.19 0.14 0.11 0.13 0.14 0.13 0.11 0.12 0.13 0.13 0.18 0.40

Fe (ppm) 40.1 47.8 30 28 19 50 36.7 38 62 47.2 74.9 46 33.1 32.6 7 14.9 36

Co (ppm) 0.05 0.1 0.07 0.01 3.1 0.04 0.05 0.50 0.10 0.06 3.30

Cu (ppm) 4.9 5.6 4 4.2 2 10.8 15.1 9 4.7 4.8 6.2 0.3 8.3 9.2 4.4 15

Mn (ppm) 40.0 33.5 5 24 12 16.3 18.9 58.4 45 46 18 7.5 18.1 21.9 2.5 30

Zn (ppm) 30.9 41 20 18 10 15.4 23.6 32.2 37 35.8 29.5 15 17.2 21.4 6.7 30

Vitamins

Thiamin (mg per 100 g) 0.57 0.67 0.38 0.34 0.07 0.46 0.44 0.69 0.77 0.72 0.38 0.48 0.63 0.48 0.32 0.45 0.30

Riboflavin (mg per 100 g) 0.12 0.11 0.14 0.09 0.03 0.15 0.15 0.26 0.14 0.16 0.22 0.12 0.22 0.12 0.05 0.10 0.10

Nicotinic acid (mg per 100 g) 7.40 11.10 2.80 4.62 1.60 4.84 7.20 1.52 0.97 0.91 2.70 1.30 1.32 3.70 0.70 2 3

Pyridoxine (mg per 100 g) 0.35 0.43 0.53 0.92 0.45 0.59 0.44 0.34 0.12 0.21

Pantothenic acid (mg per 100 g) 1.36 0.66 1.35 0.75 1.25 0.57 0.73 1.36 1.23 1.09 1.10 0.82

Biotin (mg per 100 g) 0.01 0.01 0.01 0.02 0.01 0.01 0.02

Folacin (mg per 100 g) 0.04 0.04 0.03 0.02 0.02 0.02 0.04 0.05 0.06 0.02

Carotenes (mg kg

1

) 0.2 0.2 29.5 15.7 1 5.4

Vitamin E (mg kg

1

) 12.8 28 24 1.7 0.14 13.8 24.8 16.6 16.7 17 19 22 31

Seealso: Dietary Fiber:PropertiesandSources;

Determination;EffectsofFiberonAbsorption; Energy:

MeasurementofFoodEnergy; Kwashiorkor; Maize;

Malnutrition:TheProblemofMalnutrition; Marasmus;

Pellagra; Rice; Sorghum; Spoilage:MoldsinSpoilage;

Starch:ResistantStarch; Wheat:TheCrop

Further Reading

FAO (2000) Electronic page: http//apps.fao.org/. Rome:

Food and Agriculture Organization.

Finley JW and Hopkins DT (1985) Digestibility and Amino

Acid Availability in Cereal and Oilseeds. St Paul, MN:

American Association of Cereal Chemists.

Hulse JH, Laing EM and Pearson OE (1980) Sorghum and

the Millets: Their Composition and Nutrition Value.

New York: Academic Press.

Lorenz KJ and Kulp K (1991) Handbook of Cereal Science

and Technology. New York: Marcel Dekker.

Miller JD and Trenholm HL (1994) Mycotoxins in Grain.

Compounds other than Aflatoxin. St. Paul, MN: Eagan

Press.

Mirocha CJ and Christensen CM (1982) Mycotoxins. In:

Christensen CM (ed.) Storage of Cereals, Grains and

their Products. St. Paul, MN: American Association of

Cereal Chemists.

Serna Saldivar SO (1996) Quı

´mica,

Almacenamiento e

Industrializacio

n de los Cereales. Mexico, DF: AGT

Editor.

Champagne See Wines: Types of Table Wine; Production of Table Wines; Production of Sparkling Wines;

Dietary Importance; Wine Tasting

CHAPATIS AND RELATED PRODUCTS

P Haridas Rao and R Sai Manohar, Central Food

Technological Research Institute, Mysore, India

Introduction

0001 The chapati, also known as the roti, is a flat unleav-

ened baked product that forms the staple food of the

majority of the population in the Indian subcontinent.

The consumption of this traditional product is

increasing and has become popular even in areas

where, traditionally, rice has been the staple diet.

Chapatis are normally made and served hot at break-

fast, lunch, or dinner, and are eaten along with other

adjuncts in households, restaurants, and industrial

canteens. There are several culinary variations of the

chapati – the important ones being the parotha,

stuffed parotha, tandoori roti, phulka and puri. The

other culinary variations include nan, South Indian

parotha and roomali roti.

0002 Either whole-wheat flour – generally known as

atta and obtained by grinding wheat in a plate/disc

mill – or ‘resultant atta’, a byproduct of the roller

flour-milling industry, simulating whole-wheat flour,

is used for the preparation of chapatis. Sometimes,

whole-wheat flour is first sieved to remove 3–5% of

the coarse bran, and then used for chapati-making.

The flour, after having been mixed with water to form

the dough, is sheeted to a circular shape, and baked

on a heated iron plate or on an electric hotplate.

The major differences between chapatis and similar

products arise mainly from differences in processing

conditions. Puri is prepared similar to chapati, but

it is deep-fat-fried instead of being baked. The nan is

a lactic fermented flat product. South Indian parotha

is a nonfermented, laminated product. Roomali roti is

a very thin product baked in an inverted heated

convex iron plate. The nan, South Indian parotha,

and roomali roti are basically made from refined

wheat flour obtained from roller flour-milling oper-

ations. (See Flour: Roller Milling Operations; Wheat:

The Crop.)

Characteristics of Products

0003The chapati and its culinary variations come under the

category of unfermented flat breads; consequently,

they are dense in texture, comprising mostly crust

with little or no crumb (Figure 1). But, in a few

products, viz., nan, south Indian parotha, and tan-

doori roti, the crumb-to-crust ratio is higher. They are

CHAPATIS AND RELATED PRODUCTS 1033

usually round, but may occasionally be made triangu-

lar or rectangular in shape. The diameter varies from

10 to 20 cm, and the thickness from 3 to 10 mm. The

desirable characteristics for these products are a soft,

smooth, and pliable texture, light creamish brown

color, slight chewiness, and wheaty aroma. However,

there are very few distinct differences in the product

characteristics of the various forms of chapatis.

Chapati

0004 The chapati is circular with a diameter of 10–15 cm

and a thickness of 2–3 mm. The dough sheet is baked

on a heated iron plate and puffed on a live coal fire

or flame. The thinner chapati, with a thickness of

1–2 mm, is known as ‘phulka’.

0005 Complete and full puffing is one of the important

quality attributes of a chapati, as it results in a soft

and pliable texture. The chapati should have an

attractive appearance without any cracks on the

surface. The surface should have uniformly distrib-

uted lightbrown spots. The texture should be soft,

smooth, and pliable, and these characteristics should

be retained for at least 2–3 h of storage.

0006 The chapati should have a sweetish, wheat taste,

and a baked wheaty aroma, and it should not be

perceived as being tough and leathery when chewed.

Parotha

0007 Like the chapati, the parotha is also made from

whole-wheat flour or resultant atta. Parotha dough

contains salt and fat. The dough is sheeted and lamin-

ated at least three times; oil is applied during

lamination as well as during baking.

0008The major difference between the chapati and the

parotha is that the latter contains four to eight discrete

layers, and has a more pronounced taste and flavor of

oil. In view of the presence of oil, its keeping quality is

better than that of chapatis. The parotha is slightly

thicker (4–6 mm) than the chapati and is normally

triangular in shape. Its color is creamish brown and

it is slightly brittle on chewing. The parotha can be

stuffed with cooked vegetables, e.g., potato. Other

types of parotha can be made from a dough containing

leafy spices, like methi. They are either baked or fried.

Tandoori Roti

0009The tandoori roti is similar to the chapati in compos-

ition, but it is somewhat thicker and larger. It is made

in restaurants and other roadside eating places known

as ‘dhabas’. It is rarely made at home as it requires a

special type of oven, called a tandoor, which is essen-

tially an enclosed cavity dug out in a layer of clayey

soil, and heated by live coal. In some urban areas,

ovens of this type can be seen in centralized places;

customers normally bring the dough sheet and get the

rotis made and baked in the tandoor for a nominal

charge. The thickness of a tandoori roti is greater

than that of a chapati; it may be 8–10 mm thick,

and its diameter may range between 15 and 20 cm.

The crumb-to-crust ratio is greater than that of a

chapati. A tandoori roti is less pliable than a chapati;

its surface is rough and exhibits several large blisters.

The moisture content of a tandoori roti is also lower.

B C

fig0001 Figure 1 Chapati and its culinary variations. (A) Chapati, (B) parotha, (C) tandoori roti, (D) phulka, and (E) puri.

1034 CHAPATIS AND RELATED PRODUCTS

A typical baked aroma and slightly brittle and chewy

texture are considered desirable.

Puri

0010 Puri is also made from whole wheat flour but of 85–

90% extraction. Like chapati, it has a thickness of

1.5–2.0 mm and a diameter of 10–12 cm. It is a deep-

fat-fried product. The puri should completely puff on

frying. A light golden brown color with full puffing,

as well as a soft and pliable texture, are considered

desirable.

Phulka

0011 Phulka is very similar to chapati, except that it is very

thin, with a thickness of only 0.80–1.2 mm and a

diameter of 10–12 cm. The product is very light and

fully puffed. It is made from whole-wheat flour and

water, with fat and salt as optional ingredients. In

some places, phulka made with fat is preferred, as it

can be made into a very thin sheet and yields a highly

pliable product. The sheeted dough is baked on a

hotplate and puffed on live coals or on a fire.

0012 The following products (Figure 2) are prepared

from wheat flour obtained from a roller flour mill.

South Indian Parotha

0013 South Indian parotha is made from refined wheat

flour. This type of parotha is thick, with a thickness

ranging from 5.0 to 7.5 mm and has a diameter of 15–

20 cm. It is a laminated product. Since oil is applied

during lamination, discrete layers are seen in the

product. It is a soft and chewy product, creamish

white in color, and slightly pliable.

Roomali Roti

0014 Roomali roti is a very thin product made from wheat

flour, milk powder, oil, and water. It is a very thin

product with a thickness of 0.5–0.8 mm but has a

large diameter of 60–90 cm. It is served after folding

and is eaten along with other side dishes.

Nan

0015 Nan is made using flour, salt, milk, milk powder, curd,

baking soda, etc. Egg is an optional ingredient used to

improve the color and texture of the product. The nan

is circular or ellipsoidal, with a thickness of 4–6mm,

and is baked in a special tandoor oven similar to that

used for tandoori roti. The product is creamish in

color with dark spots on the surface with a typical

baked flavor. Unlike chapati, crumb-to-crust ratio is

higher. A soft texture is desired in the product.

Choice of Ingredients

0016Whole-wheat flour and water are the major ingredi-

ents used in the preparation of chapatis and other

similar products. Salt and oil form the optional ingre-

dients in products like chapatis and tandoori rotis and

phulka, while they are essential in the preparation of

parothas and stuffed parotha. Wheat flour, water, and

oil are the major ingredients of South Indian parotha

and roomali roti. In addition to wheat flour, milk and

curd are also essential ingredients in the preparation

of nan. Curd is used as a source of lactic acid bacteria.

Whole-wheat Flour

0017Whole-wheat flour, obtained by grinding wheat in a

plate/disk mill, is preferred for the preparation of

chapatis. The mill consists of two chilled-case corru-

gated iron plates placed vertically. One of the plates

is stationary, while the other rotates. The wheat

entering from the hopper is ground between the plates

due to the shearing action as well as the friction. The

particle size of the flour is adjusted by varying the

clearance between the plates. It is desirable to grind

wheat to a fine particle size, so that 80–90% can pass

through a 60-mesh sieve. It is normal practice in

households to remove 3–5% of the coarse bran from

whole-wheat flour by sieving through a 30-mesh

sieve. The resultant atta is also used for chapati

making, as it is available at a lower price, being the

byproduct of the roller flour-milling industry. There is

little difference in the composition of resultant atta

and whole-wheat flour, except that the former has

lower contents of ash and damaged starch, while its

water absorption capacity is appreciably less (see

Table 1).

0018The higher water absorption capacity of whole-

wheat flour is attributed to its greater damaged starch

content. The resultant atta has 1.5 times as much

thiamin and riboflavin and twice as much niacin as

that of whole-wheat flour. (See Niacin: Properties and

Determination; Riboflavin: Properties and Deter-

mination; Starch Structure, Properties, and Determin-

ation; Thiamin: Properties and Determination.)

0019Whole-wheat flour, obtained from medium-hard

aestivum wheat, and with the quality characteristics

listed in Table 2, is suitable for chapati-making. The

dough should show an alveograph stability value of

100–200 mm, a strength of 15–20  10

4

,andan

extensibility of 0.20–0.27 m.

0020In the case of phulka, a very fine ground wheat is

required, and normally, 100% will pass through a 60-

mesh sieve. The grinding is normally done in a stone

mill, which is similar to a plate mill, except that it has

a pair of emery stones. The damaged starch content in

such flour is very high, ranging from 18 to 20%. The

CHAPATIS AND RELATED PRODUCTS 1035