Probiotic properties of Lactobacillus paraplantarum LS-5 and its effect on antioxidant activity of fermented sauerkraut

This study aimed to investigate the safety and probiotic properties of Lactobacillus paraplantarum LS-5 isolated from traditional northeastern sauerkraut, and to assess the antioxidant capacity of different solvent extracts (ethanol, water, and hot water) of L. paraplantarum LS-5-inoculated sauerkraut. L. paraplantarum LS-5 was shown to have various probiotic characteristics, such as good survival ability under artificial gastrointestinal conditions, antagonistic activity of various pathogens, non-biogenic amines, antibiotic susceptibility, and non-hemolytic. The 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonate (ABTS) radical scavenging activity of the L. paraplantarum LS-5-inoculated sauerkraut alcohol extract (71.13%) was significantly higher than water extract (59.59%) (p < 0.05). The ferric reducing antioxidant power (FRAP) of sauerkraut alcohol extract (614.93 Trolox μmol L−1) exhibited a slightly stronger ability compared to water extract (388.53 Trolox μmol L−1) and the heated sauerkraut water extract (383.20 Trolox μmol L−1) at extract concentrations of 5.0 mg mL−1. Its 1, 1-diphenyl1-2-picrylhydrazyl (DPPH) radical scavenging activity was also stronger. It was found by principal component analysis (PCA) and Pearson that the DPPH radical-scavenging activities of sauerkraut extracts were significantly correlated with the content of polyphenols and flavonoids (p < 0.05). Unlike kimchi, Northeastern sauerkraut is consumed mainly by heating, so this study could contribute to understanding the antioxidant capacity of different solvent extracts of sauerkraut, and before and after heating water extracts.