Effect of alginate and gellan-based edible coatings on the quality of fresh-cut pineapple during cold storage.

摘要

Pineapple is one of the most popular fruits in Malaysia and consumer demand for fresh-cut pineapple is increasing in world markets. However, its shelf life is limited. The aim of this work was to study the effect of alginate and gellan-based edible coatings on changes in colour, weight loss, firmness and respiration rate of fresh-cut 'Josapine' pineapple during 16 days storage at 10+or-1 degrees C; 65+or-10% RH. Uncoated fresh-cut pineapple at the same condition served as control. The results showed that for colour, the L* (lightness) and chroma decreased over time in all treatments. However, L* and chroma in coated samples were significantly (p<0.05) higher than the control. The hue angle of control samples was significantly (p<0.05) lower than coated samples. Weight loss increased over time during storage. After 16 days, the weight loss of control was 22.4+or-0.9%, but the weight loss of both alginate and gellan coated samples were significantly lower than control (15.4+or-0.8% and 16.5+or-0.6% respectively). Respiration rate of fresh-cut pineapples with alginate or gellan coating was significantly (p<0.05) lower than control during storage. Firmness of coated samples during storage was not significantly different with the fresh sample. However, the firmness of control after 16 days was significantly (p<0.05) lower than fresh sample (1.39+or-0.19 N and 2.54+or-0.28 N respectively). The results obtained in this study indicate that alginate and gellan-based edible coatings could significantly reduce weight loss and respiration rate and maintain the colour and firmness of fresh-cut pineapple during low temperature storage as compared with the control (uncoated sample).