Content protein quality

Qi, P. X. and Onwulata, C. 1. (2011). Physical properties, molecular structures and protein quality of texturized whey protein isolate (WPl) Effect of extrusion moisture content. /. Dairy Sci. (Accepted for publication). doi 10.3168/jds.2010-3942. 

All of the above flours are white flours of ordinary whiteness. If the extraction rate is reduced still further, whiter flour known as patent flour is obtained. A patent flour can be produced from the grist of baker s grade or higher flours. The resulting flour will not only be whiter it will have a lower protein content. The quality of the protein will be higher. 

Patent flour has two classes of use. It can be used to make whiter bread or where very high protein content is required. The use of patent flour to make bread seems to be dying out. Its use does, however, remain popular in South Wales. There are various examples of products where patent flour is used for its protein quality, e.g. filo pastry and West Indian patties. Both of these products are brown so the colour of the flour is not important. 

Field Pea Flours in Pasta. Incorporation of non-wheat flours into noodles improves the protein content and quality, but may have an adverse effect on the flavor and texture of the pasta. Hannigan (38) reported that 10% substitution of wheat flour with pea or soy flour resulted in satisfactory quality of Japanese Udon noodles. 

Cottonseed, peanut, sesame seed, and soybean flours, when used as supplements, add to the quality of the protein. The improvement of protein quality was due to the flours compensating for limiting amino acids. Supplementation using various flours improved total protein, amino acid content and some physical characteristics in akamu, yeast bread and sugar cookies. 

Protein quality studies evaluating various edible portions of the winged bean plant and the results of recent International Field Trials are reviewed. Research efforts have been focused upon the mature seed (protein content 20.7-45.9% in 240 accessions), which is occasionally eaten in parts of Indonesia and Papua, New Guinea. Autoclaved seed meal and wet heat treated seed meal provided a corrected PER value of 1.76 and 1.72 respectively, in comparison to casein control of 2.50. 

Determining protein quality analysis is important in food science, particularly for developing foods with targeted nutritional value, and in animal feeding and husbandry. Protein is the key component in the diet of any farmed species, particularly in aquaculture and the pet food industry, making an accurate assessment of protein utilization critically important. Protein quality analysis provides an estimate of the content and bioavailability of indispensable or dietary essential amino acids. 

A review of early studies showed that poultry performed poorly when fed diets containing unhulled safflower meal (Ravindran and Blair, 1992). Partially dehulled safflower meal, however, can be utilized in balanced diets for broilers and layers at levels limited by its fibre content. However, satisfactory performance is achieved only with supplementation with other proteins to improve the protein quality of the diet. 

Cottonseed oil has long sold at a slight premium over soybean oil because of greater stability to oxidation, and desirable flavor in fried snack foods such as potato chips. However, gossypol content, and lower protein quality put the meal at a price disadvantage. Feeding whole cottonseed to dairy cattle, whose rumen microorganisms can detoxify... 

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]. 

The concerns of the nutritionist regarding protein extend well beyond protein content and protein density. A major concern in human and anima nutrition is the quality of the protein. The term protein quality refers to the ability of a particular protein to provide a balanced pattern of indispensable amino acids. A hi -quality protein contains high concentrations of the indispensable amino acids. A low-quality protein is deficient or lacking in one or more of these amino acids. Although beans and eggs are similar, as far as protein density is concerned, the quality of egg protein is considerably better than that of protein from beans. 

The nutritional value of a food is determined by its protein quality, which depends mainly on its amino acid content, digestibility, influence of antinutritional factors, and the tryptophan to a large neutral amino acids ratio (Comai et al., 2007). 

Maleki, M., Hoseney, R.C., and Mattem, P.J. 1980. Effects of loaf volume, moisture content and protein quality on the softness and staling rate of bread. Cereal Chem. 57, 138-140. 

Dietary protein adequacy (aside from the energy/protein relationship) is a function of several protein-dependent factors the protein content of the food, the digestibility/bioavailability of the protein/amino acids within the food, the quantity of indispensable amino acids within the protein, and the relative ratio of the amino acid content to the requirements of the person(s) or amino acid standard in question. The final protein quality score is dependent on the lowest level of bioavailable indispensable amino acid, the limiting amino acid. 

TABLE 2.5 Protein content, protein digestibility, lysine and leucine contents and PDCAASs of normal and improved protein quality lines of sorghum, compared to wheat, maize, barley, and pearl millet (data from several sources as indicated)... 

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