The nutritive value of mixtures of white leaf protein and food proteins

Abstract

Abstract White leaf protein products were obtained from Medicago sativa by precipitation with isopropanol and from Chenopodium quinoa by heat fractionation and ultrafiltration/diafiltration. The isopropanol precipitated protein concentrate from Medicago contained less protein and more ash than the heat fractionated preparation from Chenopodium. The biological value of the protein fraction obtained from Medicago , estimated on rats using the Thomas‐Mitchell balance method, was 59. The biological value of the protein preparation from Chenopodium was low (36). The preparations obtained were mixed with soya bean meal, wheat gluten, bone‐meat meal, fish meal, skim milk and whey in a protein ratio 1:1. In every case, except fish meal, the biological value of the mixtures was higher than that of each component separately. This improvement of the nutritive value can not be explained from the amino acid composition; possibly the lysine availability was low. White leaf protein can, with advantage, supplement other food proteins.