Cereal protein content

Thus, the term gluten-free foods refers to food products free from these cereal proteins, or those in which cereal protein content is less than a defined amount (usually 200ppm). 

The grain or pulse forms of legumes have a high total protein content (20-26%) and can therefore be used as a natural supplement to cereals. Pulses are normally deficient in the essential amino acids methionine and cystine but contain enough lysine, whereas cereals are deficient in lysine but contain enough methionine and cystine. 

Rice is the most important staple food crop in the world and has also emerged as the model cereal species (it is the only terrestrial plant other than Arabidopsis thaliana to benefit from a completed genome sequence, and extensive EST resources are also available). Rice has a lower annual grain yield than maize (6600 kg ha-1) and the grain has a lower protein content (8%), but like maize it is easy to transform and manipulate in the laboratory, a range of useful expression cassettes have been devel-... 

Singh, V., Haken, A.E., Dowd, M.K., Niu, Y.X., Zou, S.H., and Eckhoff, S.R. 1999a. Batch steeping of com Effects of adding lactic acid and sulfur dioxide at different times on starch yields, protein contents, and starch pasting properties. Cereal Chem. 76, 600-605. 

Figure 4. Protein content (%) of sugar cookies prepared from defatted peanut, soybean, and cowpea flours at 0, 10, 20, and 30% wheat flour replacement levels. Reproduced with permission from Ref. 3. Copyright 1978, American Association of Cereal Chemists.

Soy flours and concentrates are used in compounded breakfast cereals, primarily for improving total protein content and PER. In the absence of dry nonfat milk solids, glucose is often included in bakery products formulations to impart a toasted brown color. Most... 

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). 

In terms of percentage of protein content of basic sources, the animal sources far excel the plant sources. For example, the protein content of some typical unfortified foods is as follows 20-30% for cooked poultry and meats 19-30% for cooked or canned fish 25% for cheese 13-17% 17% for cottage cheese 16% for nuts 13% for whole eggs 7-14% for dry cereals 8.5-9% for white bread 7-8% for cooked legumes and about 2% for cooked cereals. 

High-performance liquid chromatography of plant proteins is limited mainly to cereal grains, since they have a relatively high protein content compared to other plants, like vegetables and fruits. The proteins in cereals also play an important role in processing. With regard to noncereal... 

Rye has an energy value intermediate to that of wheat and barley, and the protein content is similar to that of barley and oats. However, its nutritional value is reduced by the presence of several ANFs such as P-glucans and ara-binoxylans which are known to cause increased viscosity of the intestinal contents and reduced digestibility, and other undesirable effects such as an increased incidence of dirty eggs. These effects are more pronounced in hot and dry environments, which accentuate the rate of cereal ripening prior to harvest (Campbell and Campbell, 1989), as occurs in Spain and other Mediterranean countries. Rye may also contain ergot, which is a toxic fungus that reduces poultry health and performance. 

Wood, D. E., P. L. Jessen, and R. E. Wood Industrial Application of Fast Neutron Activation Analysis for Protein Content of Food Products. Paper presented at the 52nd Annual Meeting of the American Association of Cereal Chemists, Los Angeles, California, April, 1967. 

Oat is primarily a cool season crop.1 It is grown mainly in Russia, the United States, Canada and Europe. The principal use of oat is as an animal feed. However, the popularity of oat as a part of the human diet has increased because of reports describing the beneficial nutritional properties of oat (3-glucans.2 1 Oat also has other desirable nutritional properties. The protein content of oat is much higher than that of other cereal grains, and oat oil has a favorable ratio of polyunsaturated to saturated lipid. 

Mosse, J., Nitrogen to protein conversion factor for 10 cereals and 6 legumes or oilseeds—a reappraisal of its definition and determination—Variation according to species and to seed protein content. Journal of... 

Figure 7.25. Storage modulus and loss modulus of glutenin at low moisture contents as a function of temperature (Reprinted from Trends Food Sci. Tech., 5, Kokini, Coeero, Madeka, and De Graaf, The development of state diagrams for cereal proteins, pp. 281-288, Copyright...

Furosine, a marker of the Maillard reaction product, is a valuable indicator of food protein quality. It is a marker for thermal treatment in foodstuffs and is directly related to the loss of lysine availability. IPC was employed to determine furosine content in beverages based on soy milk and cow milk supplemented with soy isoflavones [39]. Furosine was also analyzed in 60 commercial breakfast cereals to assess their protein nutritional values. The higher the protein content in the formulation, the higher the furosine levels [40]. A simple IPC technique that uses 1-octanesulfonic acid as the IPR allowed the selective determination of histamine levels in fermented food [41]. 

Dogs and cats are carnivores that have adapted to also eating cooked cereal carbohydrates and oilseed proteins. Cats are the more obhgate carnivores, typically requiring higher protein content foods on a dry matter basis. Currently, they are the only domesticated animal for which a dietary essential level of taurine, an amino acid found mainly in meat, has been established. 

In most proteins the proportion of each of the different a.a. residues, calculated as a percent of the total number of residues, ranges from 0 to about 30%. In extreme cases it may even reach 50%. Cereal proteins are generally very poor in Lys. Several major grains are deficient in Thr, Leu, Met, Val, and Trp. In most collagens there are no Cys and Trp residues, while the content of Gly, Pro, and Ala is 328, 118, and 104 residues/1000 residues, respectively. Paramyosin, abundant in the muscles of marine invertebrates, is rich in Glu (20-24%), Asp (12%), Arg (12%), and Lys (9%). The antifreeze fish serum glycoproteins contain several a.a. sequences of Thr-X2-Y-X7, where X is predominantly Ala and Y a polar residue. The antifreeze proteins of type I usually contain more than 60 mol% of Ala. Thr and Y, and in various antifreeze... 

Quinoa Chenopodium quinoa Willd) is an ancestral crop from the South American Andes. Quinoa seeds have high nutritional value and energetic content, and are consequently very suitable as food. It has a protein content of 14 to 20% and is particularly rich in essential aminoacids such as lysine and methionine, which are rare in most cereals (Sigstad and Prado, 1999). 

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