The Importance of Cereal Proteins in Daily Nutrition

Cereals stand as a vital source of energy, packing approximately 350 kcal per 100 grams. In many regions, including India, they contribute significantly to daily caloric intake, with cereals and grain legumes accounting for 70% to 90% of daily calories. Furthermore, they provide a substantial portion of dietary protein, although their protein quality varies.

Unfortunately, cereal proteins are often lacking in essential amino acids, particularly lysine. Maize, in particular, is deficient in both lysine and tryptophan, a precursor to niacin. This deficiency underscores the importance of a mixed diet containing diverse proteins to meet nutritional needs adequately.

Among cereals, rice stands out for its relatively higher lysine content compared to others. This makes rice protein comparatively better in quality. Additionally, rice is a notable source of B-group vitamins, especially thiamine. However, it lacks vitamins A, D, C, and is relatively poor in calcium and iron.

As our understanding of nutrition evolves, efforts are underway to enhance the quality of cereal proteins through breeding and biotechnological interventions. While cereals remain a staple in many diets worldwide, optimizing their nutritional content remains a priority for ensuring overall health and well-being.
The Importance of Cereal Proteins in Daily Nutrition

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Removal of bran from paddy grains

A rice kernel is covered by two layers. The outer layer is called the husk or hull and the inner layer is the bran. The whole rice kernel, including these two layers, is called paddy (rough rice). Most rice varieties are composed of roughly 11% of bran layers. The outer bran layer of the grain and embryo (germ) is what gives rice its color and can vary from light yellow to red to dark purplish black.

The rice milling is the process that helps in removal of hulls and bran’s from paddy grains to produce polished rice.

The most important rice milling operation, removal of some or all of the bran layers by abrasion, or “pearling”, as it is called. The basic objective of a rice milling system is produce an edible, white rice kernel that is sufficiently milled and free of impurities.

Rice that has had its bran and hull layers removed by milling is called white, table, polished, or milled rice. The quantity of bran remaining on the surface of the grain after milling is defined as milling degree. A high milling degree means that the milled rice is very white with relatively light milling.
Removal of bran from paddy grains

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Wild rice (Zizania spp.)

Wild rice, technically not a rice and since the era of paddy production mostly not wild, is the only cereal native to North America with well documented food uses. Wild rice has been a successfully crop in California because production economics have been favorable; the crop adapts easily to basins that have been used for production in the Sacramento Valley.

Wild rice is a grass belonging to the family Gramineae, the genus Zizania, and the species aquatica (or palustris). One can easily distinguish Zizania aquatica from Oryza sativa or common white rice, the Asian staple.

There are four species of wild rice:
Northern wild rice (Zizania palustris)
Wild rice (Zizania aquatica)
Texas wild rice (Zizania texana)
Manchurian wild rice (Zizania latifolia)

This wild rice has come into modern American diet as a delicious, though expensive, substitute for true rice. Or as an additive to give true rice a special flavor and texture.

Wild rice is primarily wind pollinated, a process that ensures genetic diversity through outcrossing, In addition, the plant has some capacity for self pollination.

It is an annual plant that grows form seed. Seed germination is evident when the coleoptiles that covers the leaves breaks through outer layer of the seed.

The stem diameter of the wild rice plant varies from ¼ to ½ inch. Internodes are hollow and divided by thin, porous partitions that allow the diffusion of gasses up and down the stem. Up to 50 additional secondary (tillers) can originate from the basal nodes.
Wild rice (Zizania spp.)

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Rice in general

Rice is one of the most versatile crop plants. China, India, Japan and Vietnam are some of the major rice consuming countries.

Warmer climates with abundant water are ideal for rice growth. Low temperature is a major factor limiting rice cultivation. The optimum temperature is about 30°C and temperature lower than 20°C particularly during the flowering stage, induce sterility.

Larger crops are now being cultivated in California and the southern United States and a number of varieties of rice are now commonly available.

Sweet rice is more glutinous than other varieties and is used mostly for dessert such as rice pudding.

Rice is frequently categorized into short, medium and long-grain. American long-grain white rice is large fluffy with a woody flavor. Long and short grain brown rice are also commonly available, with many varieties providing different flavors. Both may be manufactured into dry breakfast cereals and both are used in parboiling operations.

Long –grain brown rice is a beige, nutty-flavored, fluffy, light rice. Vitreous long grain rices are preferred in the domestic market for cooking and for processing into canned products such as soups.

Besides just being boiled to be eaten with vegetables, tofu, fish and so on, rice can be popped and used as a breakfast cereal cream of rice, another breakfast cereal, is made from ground rice.
Rice in general

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Nutrition of rice

Rice provides the main source of energy for more than half of the world population. It may be the major as aspect of a diet, or incorporated into the main dish, side dish, or dessert and is commonly used in the preparation of ready to eat breakfast cereals.

The chemical composition of the rice grain varies considering depending upon the genetic factor of plant variety and upon such environmental influences as location and season in which grown, fertilizer treatment, degree of milling and conditions of storage.

The protein level of rice is similar to those of potato and yam on a dry weight basis but is the lowest among the cereals.

A glutelin is the principal protein of rice. Rice also contains small quantities of albumin, globulin and prolamins.

Rice is especially important to persons with wheat allergies and is commonly eaten as a first food by infants, as it offers the least cereal allergy.

Rice contains a reasonable amount of thiamin, riboflavin, niacin, vitamin E and other nutrients. It does not contain any vitamin C, D, or A.

Generally, rice is polished during milling in order to remove the brown hull, which also removes some of the protein, vitamins and minerals. (The once-prevalent deadly disease beriberi resulted from eating polished rice (thiamin removed in the milling process) as a staple food.

The major carbohydrate of rice is starch 72-75%. The amylose content of the starch varies according to grain type the longer grained and superior types containing up to 17.5 per cent amylose while some coarse types are completely devoid it. Rice also contains some free sugars like glucose, sucrose and dextrin.

Rice also has the lowest dietary fiber. Today, most white rice is enriched with vitamins and minerals, to add back nutrients lost in milling.
Nutrition of rice

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