Effect of the metabolic activity of lactic acid bacteria and propionibacteria on cheese protein digestibility and fatty acid profile

The purpose of the study was to investigate the effect of different variants of bacterial starter cultures on the production of ripened cheeses and on the metabolism of the bacteria used. The study showed that lactic fermentation bacteria affect the proportions of fatty acids in cheeses, with SFAs accounting for many fatty acids in all cheese variants. Fatty acid proportions are complex and depend on the cheese culture and monoculture. Analysis of fatty acid composition showed variation in the proportion of saturated and unsaturated fatty acids, which affected the values of atherogenic and thrombogenic indices. The atherogenic index was highest in samples of mature cheeses obtained from a typical mesophilic cheese culture and lowest in samples of fresh milk and mature cheeses obtained from a mesophilic cheese culture and monocultures of L. casei and Propionibacterium . The study also showed that lactobacilli affect the content of available lysine, glycine, and methionine in cheese proteins, where mature cheeses obtained with Propionibacterium and L. casei starter cultures were characterized by a higher lysine and glycine content than fresh cheeses and those obtained with cheese culture only. Mature cheeses obtained with starter cultures of mesophilic cheese culture and Propionibacterium and L. casei were characterized by the highest methionine content. The results of this study suggest that the use of different cheesemaking cultures and monocultures may affect the fatty acid composition and amino acid content of cheese and fresh milk, which may have health implications.