Pg. 31-37 Evaluation of fruit coatings to reduce dehydration, pericarp browning and post-harvest decay of litchi fruit

The aim of this project was to evaluate post-harvest treatments with different acids, fruit surface coatings and waxes in order to determine the effect on internal quality, dehydration, pericarp browning and post-harvest decay development on ‘HLH Mauritius’ and ‘McLean’s Red’ fruit. Two trials consisting of 20 and 28 treatments respectively, were conducted during January and February 2008. Fruit were incubated at 3±1 °C for 40 days to simulate export conditions and kept at 10±2° C for 14 days, simulating supermarket conditions. The effect of treatments on internal quality, weight loss, colour and post-harvest decay development was recorded over time. Mauritius fruit treated with acidified prochloraz and ‘McLean’s Red’ fruit treated with acidified Semperfresh and citric acid had a slightly lower TSS than some of the other treatments evaluated in this trial. None of the treatments could improve on fruit appearance when compared to fruit treated with commercial sulphur dioxide (SO₂ ) fumigation. Fruit in most treatments had a poor appearance when evaluated after being kept for seven days at 10±2° C. Some of the products applied as 30 sec dip treatments or brush on treatments, showed improvement in fruit appearance compared to the untreated control, but efficacy will have to be improved dramatically in order to be an acceptable replacement for sulphur dioxide fumigation.