CARDIOVASCULAR EFFECTS OF WHEY FROM PROZYME 6-FACILITATED LACTIC ACID BACTERIA FERMENTATION OF MILK

Abstract

Fresh low-fat milk was fermented for up to 30 h at 42C with five mixed lactic acid bacteria. A protease, Prozyme 6, was added 5 h after the beginning of bacterial fermentation. The whey was separated from the fermented milk and freeze-dried. As the fermentation time extended to 30 h, the inhibition of lipoxygenase increased as indicated by a decrease of IC50from 3.79 to 0.47 mg powder/mL. The relative percentage of binding bile acid by whey was 39.3% in comparison to cholestyramine. Inhibition of angiotensin I-converting enzyme increased as shown by a decrease of IC50 from 1.18 to 0.24 mg powder/mL. The systolic blood pressure and diastolic blood pressure were reduced 22.6 and 21.5 mmHg, respectively, in spontaneously hypertensive rat, after 8 weeks of oral administration of diluted whey (12.5 mg powder/mL). PRACTICAL APPLICATIONS A new technique was developed in this experiment using a combination of lactic acid bacteria fermentation and protease hydrolysis to accelerate the production of bioactive peptides from fresh low-fat milk. The fermented whey product exhibited in vitro inhibition on lipoxygenase (LOX) and angiotensin I-converting enzyme, and reduced the LOX-catalyzed low-density lipoprotein oxidation. The whey product also showed higher bile acid binding capacity; thus, it might possibly have the potential of reducing serum cholesterol in vivo. Also, in vivo antihypertensive effect was confirmed on spontaneouosly hypertensive rat by long- or short-term administration. This fermented milk whey was expected to be a useful ingredient in physiologically functional foods for reduction of cardiovascular disease risk.