Abstract
The aim of this study was to evaluate the probiotic properties of Lactobacillus plantarum Ln1 isolated from kimchi and the antioxidant activities of live and heat-killed cells. L. plantarum KCTC 3108, which has been used as a commercial probiotic strain, was used as a control. L. plantarum strains (Ln1 and KCTC 3108) can survive under artificial gastric conditions (pH 2.5 in 0.3% pepsin for 3 h and 0.3% oxgall for 24 h), and adhere strongly to HT-29 cells. In addition, L. plantarum Ln1 did not produce carcinogenic β-glucuronidase, whereas it showed a higher β-galactosidase production of 3067.42 mU/mL. The antioxidant activity of L. plantarum Ln1 was assessed using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, β-carotene and linoleic acid inhibition, and reducing power assays. In all these methods, live L. plantarum Ln1 showed a higher antioxidant activity than the control strain. In heat-killed cells of L. plantarum Ln1, β-carotene bleaching inhibitory activity and reducing power was higher than DPPH and ABTS radical scavenging activity. These results suggested that live or heat-killed L. plantarum Ln1 isolated from kimchi might be useful as an antioxidant probiotic.