Proteins in human nutrition

Soybean Protein in Human Nutrition Donald S. Payne and L. S. Stuart... 

Proteins in human nutrition—Congresses. 2. Proteins—Analysis—Congresses. 3- Food—Sensory evaluation—Congresses. 

V. R. Young and N. S. Scrimshaw, Clinical Research Center and Department of Nutrition and Food Science, Massachusetts Institute of Technology, make the following authoritative statement relative to the nutritional value of processed soy protein in human nutrition ... 

Lipids in human nutrition. 2. Proteins in human nutrition. 3. 

Both finfish and shellfish are highly valuable sources of proteins in human nutrition. The protein content of fish flesh, in contrast to the fat content, is highly constant, independent of seasonal variations caused by the feeding and reproductive cycles, and shows only small differences among species. Table 4 summarizes the approximate protein contents of the... 

On a world wide basis, man obtains approximately 70% of his daily protein intake from plant sources and 30% from animal and fish sources. These figures are 50 and 50%, respectively, for the developed nations, and 83 and 17% for the developing countries. Oilseeds and pulses (dry beans, lentils and peas) are concentrated sources of proteins, and are expected to play increasingly important roles in human nutrition as world population grows. 

The proteins of milk are of great importance in human nutrition and influence the behavior and properties of the dairy products containing them. They have been studied more extensively than any other proteins except possibly those of blood. Since milk contains a number of different proteins, they must be fractionated and the proteins of interest isolated before definitive work can be done on their composition, structure, and chemical and physical properties. 

Since animals tend to concentrate in their own proteins the sulfur amino acids contained in the plants diey eat, such animal products (meat. eggs, and cheese) are valuable sources of the essential sulfur amino acids in human diets. In regions where die diet is composed almost entirely of foods of plant origin, deficiencies of sulfur amino acids may be critical in human nutrition. Frequently, persons in such areas (also voluntary vegetarians) are also likely to suffer from a number of odier dietary insufficiencies unless supplemental sources are used. 

Fruit juice is important in human nutrition far beyond its use as a refreshing source of liquid. Many fruits contain a variety of minor ingredients, particulary vitamins and minerals, as well as carbohydrates, which are the predominant solid component. Although fruit contains small amounts of protein and fat, these are not important ingredients of juices. 

While phosphorus is related to the two bivalent cation in human nutrition as in structural formation, it is also present in the blood cells as phosphates and in protein, lipids, carbohydrates and enzymes such as ATP and ADP. The U.S. RDA for phosphorus is one gram, and orange juice and grapefruit juice may contain between 15 to 20 mg per 100 ml. 

Nutritional significance. As one of the major whey proteins in human milk and also relatively abundant in bovine colostrum, LF is of interest as a dietary source of amino acids as well as for the bioavailability of iron. LF has an... 

Since selenized yeast is used in human nutrition, there is a need for full characterization of Se species. However, even more importantly, the quantitative analysis of biologically active selenomethionine is demanded. After a long-term intake of selenized yeast, the undesired accumulation in proteins occurs with increased... 

Fats and oils have major roles in human nutrition. They are concentrated dietary sources of energy, providing approximately 9 kcal/g when metabolized compared with 4 kcal/g for carbohydrates and proteins, and account for about 36 percent of domestic caloric intake per capita.19 Dietary lipids also can provide essential molecular structures that are synthesized by the body into compounds required for selective functioning of cell membranes and regulation of life processes. 

Vitamins are minor components of foods that play an essential role in human nutrition. Many vitamins are unstable under certain conditions of processing and storage (Table 9-1), and their levels in processed foods, therefore, may be considerably reduced. Synthetic vitamins are used extensively to compensate for these losses and to restore vitamin levels in foods. The vitamins are usually divided into two main groups, the water-soluble and the fat-soluble vitamins. The occurrence of the vitamins in the various food groups is related to their water-or fat-solubility. The relative importance of certain types of foods in supplying some of the important vitamins is shown in Table 9-2. Some vitamins function as part of a coenzyme, without which the enzyme would be ineffective as a biocatalyst. Frequently, such coenzymes are phosphorylated forms of vitamins and play a role in the metabolism of fats, proteins, and carbohydrates. Some vitamins occur in foods as provitamins—compounds that are not vitamins but can be changed by the body into vitamins. Vitamers are members of the same vitamin family. 

Plants represent a very important role in human nutrition, due to the large quantities of proteins, carbon hydrates, lipids, vitamins, antioxidants and mineral salts that its can supply. Sometimes the nutritional aspect can be associated with the flavour and fragrance of the extracts producing a high value products. In recent years one can observe an increase in research for natural sources, in particular from plant matrices, of additives with application in the food, cosmetic and pharmaceutical industries. 

Each amino acid has its own distinct function that works with other amino acids to build proteins. The particular combined molecular structures of the amino acids in a protein determine how it works. Of the following twenty amino acids, nine are essential (indicated by an E) in human nutrition, and the remaining eleven (indicated by an N) can be manufactured in the body. 

This chapter sets out the role and importance of protein in human health, human protein requirements, and the measurement of food protein quality. Specifically, focus is given to the need to improve sorghum protein quality and the developments that have already taken place in this area are reviewed. Lastly, the improvements in sorghum protein quality achieved to date in the Biosorghum project are presented and on the basis of these data, the potential of biofortified sorghum to improve children s nutritional status is evaluated. 

WHO/FAO/UNU Expert Consultation (2007). Protein and Amino Acid Requirements in Human Nutrition. World Health Organization, Geneva Report of a Joint WHO/FAO/ UNU Expert Consultation. World Health Organization Technical Report No. 935. Winick, M. (1979). Hunger disease. Studies by the Jewish Physicians in the Warsaw Ghetto. John Wiley Sons, New York. 

In this chapter an attempt has been made to discuss the methods available for the isolation and analysis of higher plant cell walls. Because the structures and properties of the cell wall polymers from various tissue tyjDes show considerable differences, it is emphasized that, where possible, separation of the tissues in a plant organ prior to preparation of the cell walls is desirable. Attention is drawn to the problems associated with coprecipitation of intracellular compounds with cell wall polymers, particularly in view of the occurrence of small amounts of proteoglycan and proteoglycan-polyphenol complexes in the walls and the covalent attachment of phenolics and phenolic esters with some of the cell wall polymers of parenchymatous and suspension-cultured tissues. The preparation of gram quantities of relatively pure cell walls from starch- and protein-rich tissues is discussed at some length because of the importance of dietary fiber in human nutrition and an understanding of the composition, structure, and properties of dietary fiber would be hampered without such methods (Selvendran, 1984). 

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