EVALUATION OF HYDRO-COOLING AS A POSTHARVEST TREATMENT FOR SULPHUR DIOXIDE FUMIGATED 'MAURITIUS' LITCHI FRUIT
A study was performed to establish what effect hydro-cooling has on the quality of Mauritius litchi fruit when applied before and/or after sulphur fumigation. Two trials were carried out with the Mauritius cultivar at the beginning and towards the end of the harvest window. During the trials, the temperature of the fruit was effectively reduced by hydro-cooling from around 20°C to between 5 and 6°C within 15 min. After cooling, the fruit were stored for 30 days at 1°C followed by another 6 days on the shelf at ambient temperatures. No statistically significant differences in total soluble solid content, pericarp browning or firmness were noticed after storage. However, during both the early and late season the hydro-cooled fruit were found to lose more mass than the control fruit. Another negative observation made was that the titratable acid content of the hydro-cooled fruit was significantly lower than that of the non-hydro-cooled fruit after storage. During both the early and late season, the fruit that received a hydro-cooling treatment after sulphur fumigation had higher incidences of fungal infections than the control. During the early season, the litchis that received hydro-cooling treatment before sulphur fumigation had slightly higher levels of spoilage while they had slightly lower levels during the late season. Based on the current results it would appear that hydro-cooling will not improve the quality of sulphur fumigated Mauritius litchi fruit and the technique is therefore not recommended at this stage.
Mhlophe, S.D. and Kruger, F.J. (2014). EVALUATION OF HYDRO-COOLING AS A POSTHARVEST TREATMENT FOR SULPHUR DIOXIDE FUMIGATED 'MAURITIUS' LITCHI FRUIT. Acta Hortic. 1029, 331-336
Litchi chinensis Sonn., fungal infection, air-cooling, postharvest, season, titratable acid, quality, treatment