APPLICATION OF LOCALLY ISOLATED LACTIC ACID BACTERIA METABOLITES AS BIO-PRESERVATIVES TO INCREASE SHELF-LIFE, SAFETY AND QUALITY OF SOME FRUITS

Abstract

The bio-preservation of fruits using cell-free supernatant (CFS) of lactic acid bacteria (LAB) isolated directly from locally fermented dairy products was an innovative approach. This study aimed to increase the shelf life and quality of some fruit samples during storage at room temperature by coating samples with CFS of Lb24 (L. plantarum strain MZ409592). Forty LABs were isolated from 30 locally fermented dairy products. Six LAB isolates that had the highest antimicrobial activity against pathogenic microorganisms were identified by 16SrRNA phylogenetic identification. The results showed that the six LAB strains belonged to Lactobacillus plantarum. CFS of L. plantarum Lb24 had the highest antimicrobial activity against pathogenic microorganisms using the in-vitro method. Then, fruits were coated with CFS of Lb24 at different concentrations (10%, 20%, and 30%) by sprayed method for further study. The microbiological results showed that apples, pears, and fig fruits coated with 20% and 30% of CFS of Lb24 had higher shelf life over 14, 12, and 6 days, respectively. While the control fruit samples had lower shelf life during storage at room temperature. The increase in shelf-life of the different fruits suggests the possible use of Lb24 (L. plantarum strain MZ409592) as bio-preservatives in fruits.