Effects of ozone on major antioxidants and microbial populations of fresh-cut papaya

The problems that are usually associated with fresh-cut commodities are the rapid depletion of nutritional value and the presence of high microbial populations. Ozone is a strong oxidant that can elicit physiological, chemical and microbial changes in fresh produce. Therefore, fresh-cut papaya was treated with ozone (9.2 +/- 0.2 mu l/L) at 10,20 and 30 min.to investigate its effect on phytochemicals and microbial load. Following a 20 min ozone treatment, the total phenolic content of fresh-cut papaya increased by 10.3% while the ascorbic acid content decreased by 2.3% compared to that of untreated control fruit. Also, gaseous ozone reduced microbial counts being more effective on coliforms (0.39-1.12 log 10 CFU/g) than on mesophilic (0.22-0.33 log 10 CFU/g) bacteria. The results suggest that microbial populations on fresh-cut papaya can be reduced without depleting its major antioxidants except for ascorbic acid when subjected to 9.2 +/- 0.2 mu l/L gaseous ozone for 20 min. (C) 2013 Published by Elsevier B.V.