Effect of hydro cooling and packaging on the shelf life of cold stored destalked litchis cultivar Taiso

Abstract

Selected litchi fruits cultivar Taiso harvested at full red color stage were destalked and were (a)  non-hydro cooled and (b) hydro cooled at 0 - 1ºC for 12 to 15 minutes until the core pulp temperature reached 5ºC and were packed in LDPE plastic packaging, clip-on barquettes , opaque plastic bags,70  micron thick and cold stored at 5 ºC. Significant difference in cumulative percentage weight loss for the treatments and over storage time was observed, non-hydro cooled fruits stored in clip-on barquettes at  30 days having a significantly higher cumulative percentage weight loss of 1.86 percent compared to hydro cooled fruits in opaque plastic bags had the least percentage weight loss of 0.83 percent +-S.E 0.06. Percentage pericarp browning in hydro cooled fruits was minimal. Hydro cooled and non-hydro cooled fruits packed in LDPE plastic 30 micron and in clip-on barquettes had a negligible percentage of  fruits whose peel cover had browned by more than 25 percent. Hydro cooled fruits packed in opaque plastic 70 micron thickness had 20 percent fruits browned by more than 25 percent peel cover. No fungal growth was observed on the hydro cooled fruits irrespective of packaging. Total soluble solids and acidity  values remained stable for all the treatments. It is recommended to hydro cool fresh destalked litchis in iced water(0-1 ºC) until the core flesh temperature reaches 5 ºC, when  packed in clipon or LDPE plastic 30 micron , pericarp browning was minimal at 3 weeks storage and no fungal growth was observed on the fruits.

Key words:-post harvest, litchi, hydro cooling, packaging, shelf life.