Growth Response of Lactobacillus casei variety casei to Proteolysis Products in Cheese during Ripening

Abstract

Water extracts of Cheddar cheese at different ages up to 180 days were fractionated on Sephadex G-50 with pyridineacetic acid buffer pH 5.1. Six and nine fractions were obtained from fresh and ripened cheese, respectively, some of which stimulated growth. A fraction containing riboflavin was stimulatory to Lactobacillus casei variety casei. The stimulatory fractions contained N-acetylhexosamine and 23 to 27.8% glutamic acid of the constituent amino acids. Most of the alphas-casein disappeared from the cheese at 35 days while beta-casein remained. Para-kappa-casein was not proteolyzed at 170 days of cheese ripening. The significance of alpha-casein proteolysis in Cheddar cheese is discussed.