Comparative assessment of soy and milk protein quality in infant cebus monkeys.
Protein qualities of lactalbumin (L), casein (C), soy concentrate (SC), soy isolate (SI), and soy isolate plus 15.3 mg methionine/g protein (SIM) were investigated in a slope-ratio assay using 32, 8-wk old cebus monkeys. Growth (28 days) and nitrogen balance (NB) (days 19-28) data were evaluated in a multiple-regression format with nitrogen intake and body weight as the independent variables. Based upon growth, potencies compared to L were: C, 72.1; SC, 52.5; SI, 40.6; and SIM, 72.2. Based upon NB, comparable potencies were: C, 62.2; SC, 69.0; SI, 46.8; and SIM, 90.7. NB data showed that the potency of SC was significantly greater than SI and that methionine supplementation of SI improved it to a potency not distinguishable from the standard. The marked improvement from SI to SIM emphasizes the beneficial effect of sulfur amino acid supplementation of soy protein for an infant primate species.
D000818:Animals; D000833:Animals, Suckling; D001798:Blood Proteins / Q000032:analysis; D001835:Body Weight; D002428:Cebus; D004063:Digestion; D005260:Female; D006400:Hematocrit; D007408:Intestinal Absorption; D008297:Male; D008715:Methionine / Q000032:analysis; D008894:Milk Proteins / Q000378:metabolism / Q000494:pharmacology*; D009584:Nitrogen / Q000378:metabolism; D009753:Nutritive Value; D014674:Plant Proteins, Dietary / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D030262:Soybean Proteins
D001798:Blood Proteins; D008894:Milk Proteins; D014674:Plant Proteins, Dietary; D030262:Soybean Proteins; D008715:Methionine; D009584:Nitrogen