Pg. 40-46 Effect of different post-harvest treatments on retention and overall quality of litchi fruit during low temperature storage

Litchi fruit cv. Mauritius were subjected to post-harvest dip treatments in potassium metabisulphite (250 ppm), Vapogard® (0.1%), Chitosan (0.1%), combined potassium metabisulphite (250 ppm) and Vapogard® (0.1 % ), combined Chitosan (0.1 % ) and potassium metabisulphite (250 ppm), combined Anolyte® (2%) Triton X-100 and chitosan, combined ammonia solution (0.5%) and Carnauba wax (1%). The fruit were held for 21 days in cold storage at 1°C and 95% relative humidity (RH) to simulate refrigerated sea shipment conditions; thereafter at simulated retail shelf conditions at 18°C and 80% RH for 2 days. Fruit were evaluated for decay, marketability, desiccation and browning.
The combined potassium metabisulphite and Vapogard® treatment retained the marketability of the fruit most effectively by reducing browning severity, post-harvest diseases and fruit firmness compared to commercial sulphur dioxide fumigated fruit. This treatment also revealed superior taste compared to the commercial sulphur dioxide fumigation with 19. 5% soluble solid concentration and 0.2% titratable acidity. The red colour retention was highest in fruit dipped in potassium metabisulphite and Vapogard®, and a decline in anthocyanin concentration was also evident in this treatment. This combined treatment provided an effective alternative for commercial sulphur dioxide fumigation.