Determination of peroxy radical-scavenging of lactic acid bacteria

Responses of lactic acid bacteria (LAB) to peroxy radicals generated via th ermal (40 degreesC) decomposition of the diazocompound 2,2,-azo-bis (2-amid inopropane) dihydrochloride (ABAP), were studied. In general. LAB displayed survival curves with shoulders and tails indicative of 'multihit' killing by exposure to peroxy radicals. One strain, Lactococcus lactis subsp. lacti s DIP15, producing a slope of 0.0105 in the kinetic analysis when exposed t o 4 mM ABAP, exhibited a measurable antioxidant capacity. The other LAB fai led to show any significant antioxidant capacity. The antioxidant capacity of strain DIP15 remained constant after cells have been heat-treated. sugge sting that compounds bearing free radical scavenging capacity are rather st able. (C) 2001 Elsevier Science BN. All rights reserved.