Effect of modified atmosphere packaging by PE and PVC on quality changes of lychee fruits

Lychee fruits were packed in tray and wrapped with polyethylene (PE) and polyvinylchloride (PVC) films. The trays were then stored at 5 degrees C and determined for quality changes for three-day intervals. The results indicated that lychee wrapped with PE showed slight change in weight loss during 12 days of storage, whereas 6% weight loss was obtained on the 9(th) day by using PVC wrapping. The red colour of lychee peels was brighter in PE than PVC except on the 12(th) day of storage, while no significant difference was detected in the lychee flesh. The firmness of lychee fruits decreased sharply from 0 to 3 days in both PE and PVC. There were no significant differences in titratable acidity and total soluble solid contents of lychee fruits wrapped with PE and PVC. In addition, the sensory evaluation was also studied and the result indicated that the general acceptance and sweetness scored higher in PVC than in PE. Moreover, fruit decay was found in PE rather than in PVC. It can be concluded that modified atmosphere packaging using PVC film wrapping might be more effective for extending the shelf life of the lychee fruits.