Nitrogen Balance Studies in Young Men to Assess the Protein Quality of an Isolated Soy Protein in Relation to Meat Proteins

Abstract

The protein nutritional value of an isolated soy protein was examined in healthy young men during 10-day N-balance periods. In the first study (expt 1), 10 young men received a diet providing a test protein (N X 6.25) intake of 0.6 g protein per kilogram per day with nitrogen from either lean beef, isolated soy protein or various combinations of the two sources. No differences in N balance, digestibility or net protein utilization were observed when the soy protein replaced beef. In the second study (expt 2), three separate groups of seven young men each received graded intakes of either beef or an isonitrogenous mixture of beef and the isolated soy protein or dried skim milk. An estimate was made of the N intake from each source required for N equilibrium. These values were 116, 106 and 103 mg N/kg per day, respectively. No statistically significant differences were found among the three dietary groups. Thus, the protein quality of the isolated soy protein appears to be comparable to that of animal protein sources such as milk and beef.

Maximizing muscle protein anabolism: the role of protein quality

“…Instead, despite high protein quality ( Fig. 1) [45][46][47][48][49][50], the digestion rate of proteins (e.g. whey and casein as well as soy protein) influences protein turnover and how amino acids support protein synthesis in central versus peripheral tissues [51][52][53][54].…”

“…NPU for casein and whey from reference [49]. NPU for soy from reference [50]. , casein; , whey; , soy.…”

Technology development of protein rich concentrates for nutrition in extreme conditions using soybean and meat by-products

“…Preparation of the SPLC Products of soybean in combination with products of animal origin can be successfully applied to improve the nutritional and biological value of food concentrates for diets in extreme conditions (Bojcova et al, 2011;Kalenik et al, 2012;Wayler et al, 1983). The results of numerous studies have shown that extraction from germinated soybean seeds is the most preferable option, from the standpoint of preparation and isolation of protein substances, due to the positive effects of germination on reduction of the content of anti-nutritional substances (trypsin inhibitors, the Bowman-Birk, urease), the increase in the content of mineral substances and vitamins and removal of the shell (Bau et al, 1997).…”

Vernon Young and the development of current knowledge in protein and amino acid nutrition. Vernon Young 1937–2004

“…As a result, the agenda of the next FAO/WHO/UN University meeting in 1981 was set and the report (Food & Agriculture Organization/World Health Organization/United Nations University, 1985), on the basis of both short-and long-term balance data, duly raised the safe allowance to 0·75 g/kg per d. This value was adopted by national bodies around the world. Apart from N-balance studies on the elderly (Gersovitz et al 1982) following up earlier work (Uauy et al 1978a) and a major series of studies on the nutritional value of soyabean protein (Istfan et al 1983a,b;Scrimshaw et al 1983;Wayler et al 1983;Young et al 1984), the early 1980s were to mark the end of Young's N-balance studies aimed at the adult protein requirement. The magnitude of this part of his work is apparent from his recent meta-analysis of all published data on adults (Rand et al 2003), used as the basis of the recent US dietary reference intakes report on protein requirements (Institute of Medicine, 2002).…”