Antimicrobial activity of fermented fruit juices on selected foodborne pathogens

Abstract

The present study evaluate the antimicrobial activity of seven fermented fruit juices (FF), namely lime, orange, kaffir lime, pineapple, avocado, star fruit and sugar cane. The antimicrobial activity of these FF was tested against seven foodborne pathogens, namely Campylobacter jejuni ATCC 29428, C. jejuni FBRL-S32, C. jejuni FBRL-S08, Listeria monocytogenes, Pseudomonas aeruginosa, Bacillus cereus and Escherichia coli O157:H7 using paper disc diffusion method. The results showed that seven FF inhibited all tested strains. The FF made from avocado fruit yielded the greastest clear zones. After adjusting the pH from 3.1-3.4 to 6.5-7.0, antimicrobial activities of FF on all pathogens reduced. However, FF made from lime, orange, kaffir lime, pineapple and sugar cane still gave clear zone on some pathogens. After adjusting pH, FF made from avocado and star fruit showed no clear zone on all pathogens. Chemical analysis by HPLC showed that FF contained various organic acids including oxalic acid, tartaric acid, malic acid, ascorbic acid, lactic acid, acetic, citric and benzoic