Nutrition Evaluation of Whey Protein Concentrates and Their Fractions

Nutritional evaluation of whey protein concentrates and whey protein fractions was performed by Protein Effi-cier~cy Ratio and Net Protein Utilization assays as well as by calculations of chemical scores. The whey protein concentrates were industrially produced by gel filtration and ultrafiltration and were fractionated further by large-scale gel filtration. Nutritional values of the two concentrates were similar and high. Whey protein fractions containing a-]actalbumin had high Protein Efficiency Ratio and Net Protein Utilization values while fractions containing/3-1actoglobulin had high Net Protein Utilization values but only moderate Protein Efficiency Ratio values. According to the calculated chemical scores, amino acid contents of the concentrates and of all the fractions were almost adequate to cover the needs of the human infant and more than adequate to cover those of young children. Utilization of the ~-lactalbumin-rich fraction III in humanized breast milk substitutes is discussed.