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Protein combining (also protein complementing) is a dietary strategy for protein nutrition by using complementary sources to optimize biological value. Originally applied to livestock feed for animal nutrition, since 1971 it has become a chemical critique of food values of vegetarian dishes, although it is a myth that plants have "incomplete" proteins, as all of them have all 9 essential aminoacids, and no meat or combination of vegetables is required to get enough of them. ==Concept== Protein nutrition is complex because any proteinogenic amino acid may be the limiting factor in metabolism. Mixing livestock feeds can optimize for growth, or minimize cost while maintaining adequate growth. Similarly, human nutrition is subject to Liebig's law of the minimum: The lowest level of one of the essential amino acids will be the limiting factor in metabolism. The first biochemist to enter the field was Karl Heinrich Ritthausen, a student of Justus von Liebig. When Ritthausen died in 1912, Thomas Burr Osborne praised his efforts in biochemistry: :As a result of his later work he proved that wide differences exist between different food proteins; and he was the first to direct attention to this fact, and to discuss its probable bearing on their relative value in nutrition.〔Osborne, Thomas Burr (1913) "In Memorium: Heinrich Ritthausen", ''Biochemical Bulletin'' 2:338, published by the Columbia University Biochemical Association〕 Osborne continued what Ritthausen started and published ''The Vegetable Proteins'' in 1909. He then joined forces with Lafayette Mendel at the Connecticut Agricultural Experiment Station to determine the essential amino acids. Thus Yale University was the early center of protein nutrition, where William Cumming Rose was a student. He also worked to determine the essentials, and later led the Biochemistry Department at the University of Chicago. The principle of protein combining was explained by J. Rigó: :The biological value of proteins in general, hence also of grain-proteins, is fundamentally determined by the ratio between the essential amino acids to be found in cereals and the requirement of essential amino acids of the living creature, consuming protein...the most important way of raising the biological value ... () given by the technique of complementing.〔Rigó, J. (1985) "Nutritional Functions of Cereals", in ''Amino Acid Composition and Biological Value of Cereal'', Radomir Lásztity & Máté Hidvégi editors, International Association for Cereal Chemistry〕 Many plant proteins are lower in one or more essential amino acids than animal proteins, especially lysine, and to a lesser extent methionine and threonine. Nonetheless, eating a variety of plants can serve as a well-balanced and complete source of amino acids.〔 Nevin S. Scrimshaw took this knowledge to India and Guatemala. He designed meals using local vegetables to fight against the scourge of kwashiorkor. In Guatemala he used the combination of cottonseed flour with maize, while in India he combined peanut flour with wheat.〔(Scrimshaw obituary ) from Massachusetts Institute of Technology〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「protein combining」の詳細全文を読む スポンサード リンク
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