Antioxidative activity of lactic acid bacteria isolated from skim milk / Ahmad Syafiq Mohd Fauzi

Antioxidant plays an important role in dealing with oxidative stress that may lead to various types of disease such as cardiovascular disease and cancer. There has been considerable interest and research on the use of lactic acid bacteria as an antioxidant source. This research project was carried out to determine the antioxidative activity of skim milk when fermented with lactic acid bacteria Two strains of lactic acid bacteria were used in this study and fermented with skim milk before the antioxidative activity was determined by measuring the scavenging activity of diphenylpicryl-hydrazyl (DPPH) radical on supernatant and cell pellet fraction. The growth of lactic acid bacteria was found to be increased in three logs after 48 hour of fermentation in skim milk. The supernatant and cell pellet fractions of both strains of lactic acid bacteria grown in skim milk were able to scavenge the DPPH radical by up to 690/o and 72% respectively. The ICso of the supernatant fraction was found to be in the range of 0.30 to 0.18 at 24 hour and 48 hour while the cell pellet fraction was 0.33 to 0.24 at 24 hour and 48 hour. Fermentation of lactic acid bacteria with skim milk was found to increase the scavenging activity of DPPH radical compared to skim milk without lactic acid bacteria that and LAB fermented skim milk may be used as a new source of antioxidant.