Surface sterilization of whole tomato fruit with sodium hypochlorite influences subsequent postharvest behavior of fresh-cut slices

Abstract

Experiments were conducted to investigate the effect of concentration (0, 0.26 or 1.05%) and duration (0, 20 or 60 s) of sodium hypochlorite treatment on subsequent firmness, electrolyte leakage, respiration, and C 2 H 4 production of light-red tomato ( Lycopersicon esculentum Mill.) fruit slices during storage at 5°C under modified atmosphere (MA). Pericarp firmness of slices was lower for all treatments than for untreated controls. After 12 days of storage, pericarp firmness of slices from fruit that had been treated with 1.05% sodium hypochlorite for 60 s was less than one-half the firmness of water-treated controls and lower than the other sodium hypochlorite treatments. The effect of sodium hypochlorite on electrolyte leakage of slices stored at 5°C was more closely related to treatment duration than to sodium hypochlorite concentration. The difference in electrolyte leakage between control fruit and fruit treated with 1.05% sodium hypochlorite for 60 s was 14.2, 25.6, and 25% at 4, 8, and 12 days, respectively. Development of water-soaked areas was observed on slices from fruit treated with sodium hypochlorite, but little development of water-soaked areas was detectable on slices from control fruit. An increase in C 2 H 4 and CO 2 production due to infection by Alternaria alternata was observed on slices from control fruit. These results suggest that routine surface sterilization of tomato fruit prior to postharvest experimentation may lead to physiological and biochemical alterations in the behavior of fruit.