Inhibition of angiotensin I ‐converting enzyme and lipid peroxidation by fermented rapeseed and flaxseed meal

This study investigates the inhibition of angiotensin I ‐converting enzyme ( ACE ) and lipid peroxidation of fermented rapeseed and flaxseed meals. Rapeseed and flaxseed meals were fermented with L actobacillus helveticus , L actococcus lactis ssp. lactis , B acillus subtilis , and K luyveromyces marxianus monocultures at 37°C or 30°C for 48 h. The ACE ‐inhibition potencies increased by 20–37% during fermentation with L. helveticus and B . subtilis , whereas fermentation with other strains did not produce a significant change in ACE inhibition. The lowest IC 50 value of 0.36 mg/mL was found with flaxseed fermented by L. helveticus . The same strains were also able to produce compounds that inhibited lipid peroxidation. The results showed that L. helveticus and B . subtilis degraded effectively rapeseed and flaxseed proteins as the amount of low molecular weight compounds increased during fermentation. ACE inhibition was found in low molecular weight (300–500 Da) fractions. In fermented rapeseed, the inhibition of lipid peroxidation was found in 1200–1300 Da fractions and fermented flaxseed showed inhibition in several fractions, first around 1300 Da and at lower molecular weight fractions 300–500 Da. The results demonstrated that fermentation with L. helveticus or B . subtilis produce compounds that may have beneficial effect on cardiovascular health.