LAUSR

Abstract The proteolytic activity of three Lactococcus lactis strains used as adjunct cultures and their capability to produce peptide inhibitors of the angiotensin-converting enzyme (ACE) in cheese models was studied. Initial and overall proteolytic activity of L. lactis strains were determined. Over the ripening period, water-soluble extracts of cheese models were analyzed for overall proteolytic activity and ACE-inhibitory activity. The ACE-inhibitory capability, increased over the 5 wk period of cheese models ripening (from 40.6 to 94.3%), in contrast to the IC50 value (from 0.84 to 0.32 mg mL-1). After 5 wk of ripening, all cheese models were characterized by a high capability for ACE inhibition >80%. The use of the Lactococcus bacteria led to lower IC50 values (0.32–0.44 mg mL-1) compared to the value determined for the control cheese model (0.49 mg mL-1) after 5 wk of ripening. The proteolytic activity of the three Lactococcus strains analyzed in cheese models varied throughout the ripening period.