STORAGE QUALITY OF LONGKONG (LANSIUM DOMESTICUM CORR.) FRUIT AS AFFECTED BY OZONATED WATER AND SODIUM HYPOCHLORITE PRETREATMENT

The effects of the ozonated water and sodium hypochlorite pretreatment on quality changes of individual longkong (Lansium domesticum Corr.) fruits stored at 15±1°C were investigated. The fruits were soaked at 1.0 ppm ozonated water for 15 and 20 min; 100 and 200 ppm sodium hypochlorite solution for 5 min and untreated for the control. After drying under cold air, six fruits were placed in a 135×187×36 mm polypropylene tray with a water absorbent sheet underneath and a sachet of ethylene absorber (3 g/sachet) each. Each treatment were wrapped with polyvinyl chloride film which are tightly sealed with an adhesive tape, and stored at 15±1°C. No visible symptom of fruit spoilage was observed during the first 12 days of storage in all treatments. However, all treatments significantly reduced microbial populations by analyses of the total viable, yeast and mold counts on both longkong pericarp and pulp before and after 12 days storage. At 14 days of storage, the observed L* and b* values of fruit pericarp color did not differ statistically within treatment, but the fruit spoilage was significantly lower in 100 ppm sodium hypochlorite solution pretreatment compared to the other treatments. Total soluble solids and titratable acidity gradually decreased with storage regardless of treatment. Sodium hypochlorite slightly reduced microbial population.