Abstract: To obtain functional meat starters with high antioxidant activity, three strains of lactic acid bacteria (Lactobacillus plantarum NJ107 and KM119, and L. fermentum GZ114) isolated from Chinese traditional fermented sausages were selected to compare their in vitro functional characteristics. The in vitro antioxidant activities of the fermentation supernatant, intact cells and cell-free extracts of each strain were evaluated. The in vitro probiotic properties were evaluated by surface hydrophobicity, and the ability to tolerate simulated gastroenteric fluid and bile salt. The results showed that all three strains had good antioxidant activity in vitro. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and reducing capacity of the fermentation supernatant were significantly higher than those of the intact cells and the cell-free extracts (P < 0.05), and among the three strains, GZ114 displayed the highest DPPH radical scavenging activity. The hydroxyl radical scavenging capacity, superoxide anion radical scavenging capacity and ferrous ion chelating capacity of the intact cells were significantly higher than those of the fermentation supernatant and the cell-free extracts (P < 0.05), and the highest hydroxyl radical scavenging capacity, superoxide anion radical scavenging capacity and ferrous ion chelating capacity were observed in KM119, GZ114 and NJ107, respectively. The superoxide dismutase (SOD) activity of the fermentation supernatant were significantly higher than those of the intact cells and the cell-free extracts for all three strains (P < 0.05). The activities of glutathione peroxidase (GSH-PX) and catalase (CAT) in NJ107 and GZ114 were significantly stronger than those in KM119 (P < 0.05). In terms of decreasing surface hydrophobicity, these strains were ranked as follows: NJ107 > GZ114 > KM119. All the three strains showed high tolerance to simulated gastroenteric fluid and 0.5% bile salt.

Key words: lactic acid bacteria; fermented sausages; antioxidant activity; probiotic properties