Cereals protein

The reason that the caseins, which constitute nearly 80% of bovine milk, are unfolded in their native states appears to be to facilitate digestion, since the open rheomorphic structures allow rapid and extensive degradation to smaller peptides by proteolytic enzymes. The natively unfolded structures of many cereal proteins may serve an analogous purpose since they provide nutrition for seedlings. The physiological function of the synucleins in the brain is as yet unclear, but tau is known to promote and stabilize the assembly of microtubules. 

Cereal proteins when classified by the Osborne sequential extraction method yield four different classes albumins, which are water soluble, globulins, which are soluble in salt solutions, prolamins, which are soluble in alcohol-water mixtures, and glutelins, which are soluble in dilute acid or alkali. Chen and Bushuk added a fifth fraction by dividing the glutelin into two fractions, one soluble in dilute (0.05 m) acetic acid and the other insoluble in this reagent.5... 

The legumes have a high lysine content (7,32), which makes them an excellent complement to cereal proteins. Protein contents of pumpkin breads were 5,0, 5,6, 6,2 and 6,7% for loaves that had 0, 20, 35 and 50% Navy bean flour, respectively. 

Potatoes are an excellent source of carbohydrates and contain significant amounts ofphosphorus, potassium, calcium, and vitamins, especially vitamin C. Potato protein content, at over 10%, is relatively close to that of wheat flour (11%) also, thanks to their lysine, methionine, cystine and cysteine contents, potatoes are a valuable supplement to cereal proteins. For instance, potatoes provide a significant source of proteins (10-15% of total requirements), a major source of vitamin C, an important source of energy, and also minerals like iron and other vitamins such as thiamin, nicotinic acid, riboflavin, and pro-vitamin A (p carotene) (Salunkhe and Kadam, 1991). 

Table 11 Reason for Determination of Cereal Proteins in Foods and Food Products...

Optimization of protein Separation of cereal proteins Reversed-phase 114, 123, 127, 131-133... 

Bietz. Separation of cereal proteins by reversed-phase high-performance liquid chromatography. J Chromatogr 255 219, 1983. 

Szabo, E., Haj6s, G., and Matuz, J. 2002. Identification of major allergens of cereal proteins by electrophoretic methods. Pol J Food Nutr Sci 1 l/52(Suppl. 2) 131-134. 

Advances in Modifications of Biochemical Properties of Cereal Allergens The Effect of Environmental Stresses on Allergic Properties of Cereal Proteins and the Problem of Safety of Genetically... 

ADVANCES IN MODIFICATIONS OF BIOCHEMICAL PROPERTIES OF CEREAL ALLERGENS THE EFFECT OF ENVIRONMENTAL STRESSES ON ALLERGIC PROPERTIES OF CEREAL PROTEINS AND THE PROBLEM OF SAFETY OF GENETICALLY MODIFIED CEREALS... 

Cereal proteins are only about 70 percent efficient for dietary replacement purposes. The reason is that cereal proteins are deficient in lysine, an essential amino acid for humans (see Amino Acid Synthesis in this section). Thus a diet based on one source of protein (e.g., corn) can lead to malnutrition. A partial solution to the problem has been the breeding of high-lysine corn. Other plant proteins, particularly those from pod seeds (e.g., peas and beans) are deficient in the sulfur-containing amino acids. A successful vegetarian diet will therefore be balanced in cereals and pod seeds. 

Egg protein is one of the best quality proteins and is considered to have a biological value of 100. It is widely used as a standard, and protein efficiency ratio (PER) values sometimes use egg white as a standard. Cereal proteins are generally deficient in lysine and threonine, as indicated in Table... 

Kwashiorkor is a type of malnutrition associated with insufficient protein intake, usually affecting children aged 1-4 years, although it can also occur in older children and adults. It is likely caused by a combination of factors (protein deficiency, energy and micronutrient deficiency). The absence of lysine in low-grade cereal proteins (used as a dietary mainstay in many underdeveloped countries) can lead to kwashiorkor. 

Kokini, J.L., Cocero, A.M., Madeka, H., and de Graaf, E. (1994). The development of state diagrams for cereal proteins. Trends Food Set Technol, 5,281-288. 

Figure 7.23. State diagram for glutenin (Reprinted from Trends Food Sci. Tech., 5, Kokini, Cocero, Madeka, and De Graaf, The development of state diagrams for cereal proteins, pp. 281-288, Copyright (1994), with permission from Elsevier.)...

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