Pg. 40-45 Evaluation of alternative means of reducing post-harvest decay and pericarp browning of litchi fruit

In order to explore the possibilities of utilising hot water brushing technologies to reduce post-harvest decay and pericarp browning of litchi fruit, a trial was conducted using dip treatments in ambient or hot water, followed by
dips in either hydrochloric, phosphorous or oxalic acids at different concentrations and for different exposure periods.
Results, after fruit was stored for 40 days under simulated export conditions, showed that the best retention of the red pericarp pigment and control of post-harvest decay was obtained when fruit received a hot water dip treatment followed by dip treatments in either 3% hydrochloric acid or 10% oxalic acid. However, fruit of all treatments were totally decayed after 3 days incubation at 10°C, indicating that additional strategies will be necessary to ensure effective decay control after fruit have been removed from cold storage. It seems that postharvest decay and pericarp browning are influenced by several diverse factors and that several processes and different techniques will have to be employed in order to reduce these degrading factors to acceptable levels. The implementation of hot water and acid dip treatments, and therefore hot water brushing, certainly bring us closer to a solution but at this stage not without other technologies such as fungicides. The use of hot water brushing technology together with reduced, and possibly acidified fungicide concentrations and the application of fruit coatings to reduce dehydration effectively, must be explored further in order to set up a commercial acceptable protocol for the export of high quality litchi fruit.