Flour composition proteins

Whole oilseeds and legumes and their derivatives (defatted flours, and protein concentrates and isolates) are used in traditional foods as sources of protein and for their texture-modifying functions. This article reviews, on a comparative basis, processes for preparation of vegetable food proteins, compositions and characteristics of the resulting food ingredients, and their functionalities and uses in traditional foods. 

Israkam, K. and Hongsprabhas, R 2008. Influence of waxy rice protein network on physical properties of waxy rice flour composites. Kasetsart Journal (Natural Science) 42 376-386. 

Composition of Wheat and Oat Flours (wt%) Flour Water Proteins Carbohydrates Fat Ash... 

The heat deflection temperature (or heat distortion temperature) is an important material property mostly used to determine a material s useful temperature operating range. It refers to the temperature below which a moulded object can hold its own shape. It can be determined using a dynamic mechanical analyser set to apply a constant force. The HDT was determined for blends of plasticized soy flour (52% protein) and polyamide (nylon) as 45 °C when plasticized with 20 wt% sorbital, 35 °C when plasticized with 20 wt% glycerol, and 39 °C when plasticized with 10 wt% of each." When such a blend is used to make composites with natural flbres, increasing content of natural fibres also increased the HDT. 

Compositional differences in the pea seeds influence the quality of the end products. Pea flours have been used for protein enrichment of a number of cereal-based products however, undesirable sensory characteristics may limit their use, in spite of improved functional effects in food systems. The production of volatile compounds during cooking and baking of foods with pea supplementation affects their acceptability. Enzyme systems active in unheated pea flours may contribute to their functional properties, but adversely affect the sensory quality of the food. 

The protein efficiency ratio (PER) of field pea flours is considerably less than that of casein (1.46 vs. 2.50), and somewhat less than that of soy flour (1.81). However, composites of wheat flour and pea or rice and pea (50% of the protein from each source) had PER s of 2 or more (22). Thus, supplementation of cereals with pea flour results in improvement of protein quality. 

Nielsen et al. (39) used pea flour and pea protein concentrate, both cooked and raw, in noodles and spaghetti. The pasta was made from composite flours prepared by blending 33% pea flour with 67% wheat flour or 20% pea concentrate with 80% wheat flour. Protein content of the fortified noodles was approximately one-third higher than the wheat flour noodles. Addition of pea flour reduced the cooking time, but resulted in a softer product and lower yield than the wheat pastas. Precooking the pea flour improved flavor and decreased noodle dough stickiness, but the texture and yield of the cooked pasta was still less than that of wheat products. 

Raidl and Klein (43) substituted 5, 10, and 15% field pea flour in chemically leavened quick bread. The viscosity of the pea flour batters was significantly lower than either the wheat control or soy containing batters. The starch composition of the pea flour and lower water absorption properties of the protein could have affected the viscosity. Volumes of pea flour loaves were lower than the control and soy loaves. Most of the sensory characteristics of the field pea loaves were similar to those of the control quick breads. However, all flavor scores were significantly lower for pea flour products, since they had a recognizably beany or off-flavor. 

An evaluation of the composition of the cooking juices, as presented in Table IV, demonstrates, by difference, that fat is retained to a greater extent by the soy concentrate meat product than by the soy flour meat product or the ground beef. The meat product containing soy flour lost more fat during cooking than did the all-beef (Table IV). Similar results were reported by Anderson and Lind ( ). When soy protein concentrates are used in canned meat products like chili, the fat islands within the chopped meat products and the fat cap are eliminated (10). When 4% soy concentrate was added to a minced pork product, cook out of fat and moisture was reduced 31% for pasteurized product and 34% for sterilized product. 

Tubers Tubers are quite commonly consumed by villagers in Burma. Other tropical countries also report sporadic use of winged bean tubers (59). However, in comparison to the available data on the nutrient, anti-nutrient composition and the protein quality of the seed flour, published data on the nutritional value of winged bean tuber is somewhat limited. The few reported studies dealing with a larger number of varieties grown in different locations (25,67-71) show that tubers are mainly composed of protein and carbohydrates. 

Most of the applications of HPLC for protein analysis deal with the storage proteins in cereals (wheat, corn, rice, oat, barley) and beans (pea, soybeans). HPLC has proved useful for cultivar identihcation, protein separation, and characterization to detect adulterations (illegal addition of common wheat flour to durum wheat flour) [107]. Recently Losso et al. [146] have reported a rapid method for rice prolamin separation by perfusion chromatography on a RP POROS RH/2 column (UV detection at 230nm), sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE), and molecular size determination by MALDl-MS. DuPont et al. [147] used a combination of RP-HPLC and SDS-PAGE to determine the composition of wheat flour proteins previously fractionated by sequential extraction. 

For products of dissimilar composition, e.g., isolates, concentrates, and flours, changes in the chemical environment undoubtedly elicit different responses from the various constituents of an ingredient, i.e., protein, carbohydrate, etc. Perhaps the properties of the protein can best be examined in the isolate because of its relatively low concentration of nonprotein constituents. Unfortunately, isolates usually have been subjected to the most extensive processing, which also affects the response of the protein. 

RB Gupta, IL Batey, F MacRitchie. Relationship between protein composition and functional properties of wheat flours. Cereal Chem 69 125-131, 1992. 

M Ciaffi, L Tozzi, D Lafiandra. Relationship between flour protein composition determined by size-exclusion high-performance liquid chromatography and dough rheological parameters. Cereal Chem 73 346-351,1996. 

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