Utilization of Amino Acids in Casein-Lactalbumin and Wheat Gluten when Equalized to Levels of the FAO Pattern

Abstract

Three Agricultural Experiment Stations conducted studies with human subjects to compare the utilization of wheat gluten or casein-lactalbumin, adjusted to the FAO provisional standard using crystalline amino acids, with a control mixture of crystalline amino acids in the FAO pattern. The criteria of utilization were nitrogen balance and the level of urea and ammonia nitrogen excretion. The results were as follows: 1) When wheat gluten was the test protein at a level of 0.4 g/kg body wt, the only significant difference was the lower ammonia nitrogen excretion of the Vermont men on the wheat-gluten test diet as compared to the amino acid control diet. 2) When wheat gluten was the test protein at a level of 0.5 g/kg body wt, time Maryland women, with a high calorie intake, showed significant differences for all three criteria with lower excretions of urea and ammonia nitrogen and more positive nitrogen balance on the amino acid control diet than on the wheat-gluten test diet. Apparently, the amino acid control diet was better utilized than the wheat-gluten test diet at this level of intake. 3) When casein-lactalbumin was the test protein at the level of 0.4 g/kg body wt, the Rhode Island women showed significantly better nitrogen retention for all three criteria while the Vermont men showed only the significantly lower ammonia nitrogen excretion on the casein-lactalbumin test diet.