Effect of Fermentation on Proteins of Swedish Fermented Milk Products

Swedish fermented milk products were studied for total and nonprotein nitrogen content, free amino acid profile, and molecular weight of casein and whey proteins.Nonprotein nitrogen increased in all products during fermentation.Free amino acids also increased.This resulted in an amino acid profile typical of each fermented milk product.Casein components showed only minor alterations following fermentation as revealed by gel electrophoresis.The pattern of whey proteins was changed, and decomposition of whey proteins may have contributed to elevated nonprotein nitrogen.