Determination of probiotic and antioxidant properties of lactobacillus plantarum strains isolated from pickles

In this study, probiotic and antioxidant capacities of Lactobacillus plantarum strains isolated from conventional pickles were assessed. In order to determine the probiotic capacities of L. plantarum strains, their resistance was examined against pH, pepsin, pancreatin and bile salts. For their antioxidant capacities, the level of reduced glutathione (GSH) and malondialdehyde (MDA) and the enzyme activities of glutathione peroxidase (GSH-Px) and catalase (CAT) were evaluated. Moreover, 1,1-diphenyl 2-picril hydrazyl (DPPH •) radical removal activities were measured for this purpose. The results indicated that at pH 1.0 the isolates did not exhibit any activity apart from the first hour, whereas at pH 2.0 and pH 3.0 the isolates showed some activity with time. It was found that the isolates resisted to pepsin, pancreatin and bile salt. With regards to antioxidant properties, the isolates were observed to remove DPPH radical and considerably reduce MDA levels. When the enzyme activities of GSH-Px and CAT and the GSH levels of the isolates were analysed, most of the strains were seen to show much higher activity than the controls. Moreover, the activities of Y51 and Y72 isolates at pH 1.0 were higher than other isolates. The Y5 isolate did significantly sweep DPPH, and the catalase activity of Y1 isolate was 20 times higher than the control. In general, the Y25 isolate was found to show the highest activity in terms of both probiotic properties and antioxidant capacity. In the light of these findings, the use of isolate Y25 will contribute to the food, medicine and drug-like supplement food products industries.