Liberación de péptidos bioactivos por bacterias lácticas en leches fermentadas comerciales

the aim of this study was to evaluate the release of bioactive peptides encrypted in milk proteins by proteolytic activity of lactic acid bacteria in commercial fermented milks in refrigerated storage. peptide concentration varied from 0.05 mg / ml in lf-3 (lactobacillus casei) and lf-4 (lactobacillus acidophilus) to 0.227 mg/ml in lf-5 (lactobacillus casei and s. thermophilus) and lf-1 (lactobacillus casei) after 10 days of storage, when the maximum concentration was reached. during refrigerated storage, all samples presented peptides with molecular weight lower than 14.4 kda. the fermented milk lf-2 (lactobacillus acidophilu s y streptococcus thermophilus) had the highest variety of peptides, and even peptides lower than 1.4 kda were found, some of them with aromatic amino acids, which are present in the primary structure of antihypertensive peptides. these results suggest that the concentration and diversity of peptides depends on microorganism in the fermented milk. peptides molecular weights were compared with those reported in literature for bioactive peptides, finding similarities, thus increasing the expectations to have peptides with physiological importance in fermented milks.