Abstract: The antimicrobial activity, minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of flavonoids extracted from Sedum aizoon L. on three spoilage bacteria isolated from chilled meat were investigated by double-tube dilution method and the Oxford-cup method. The effect of the flavonoids at different concentrations on pork preservation was also examined. The results showed that the flavonoids displayed different inhibitory effects on the tested bacteria and had the strongest antimicrobial activity against Aeromonas with MIC and MBC 0.675 and 2.5 mg/mL, respectively, followed by against Pseudomonad with MIC and MBC of 1.25 and 5 mg/mL, and lactic acid bacteria with MIC and MBC of 1.25 and 10 mg/mL, respectively. Based on the total number of colonies and color, 2 mg/mL of the flavonoids was determined to be appropriate for the preservation of pork. The texture, pH, water-holding capacity, total volatile basic nitrogen (TVB-N) and 2-thiobarbituric acid (TBA) values in flavonoids-treated group were better than those in the control group during storage at 4 ℃.

Key words: Sedum aizoon L. flavonoid, antimicrobial activity, pork, quality