EFFECTS OF SODIUM HYPOCHLORITE SOAKING IN COMBINATION WITH WAX COATING TO CONTROL FRUIT DECAY AND TO MAINTAIN VISUAL APPEARANCE OF FRESH VIETNAMESE LONGAN FRUIT CV. LONG

This research was designed to study the effects of sodium hypochlorite (SH) and bees-carnauba mixed wax (MW) on the prevention of fruit decay and the maintenance of visual appearance in fresh Vietnamese longan fruit cv. Long. The experiments were carried out by soaking fruits in 100, 150 and 200 ppm SH solutions for 2 min. After drying, soaked fruits were coated in 6% MW for 30 seconds, and stored at 5±1ºC for 30 days. Untreated fruits were used as control. Pericarp browning; pericarp color; pericarp pH; total microorganisms; percentage of fruit decay and weight loss; and total soluble solids (TSS) content were monitored during the storage period. The results showed that 200 ppm SH in combination with 6% MW treated fruits did not decay throughout 25 days in storage, and kept visual appearance which was indicated by the lowest browning index, high lightness (L* value) and yellowness (b* value) of fruit pericarp, as well as low pericarp pH for 20 days in storage. Moreover, this treatment maintained low total microorganism levels, low weight loss, and the TSS content of the longan fruit remained unchanged.