76C-20 |
Effect of hydroxypropyl methylcellulose-lipid edible composite coatings on plum (cv. Autumn giant) quality during storage |
M. B. PÉREZ-GAGO1, C. Rojas, and M. A. del Río. (1) Postharvest Department, Instituto Valenciano de Investigaciones Agrarias, Moncada, 46113, Spain Edible coatings on fruit surface have been proven to reduce moisture loss and improve postharvest quality of commodities. Coating performance depends on composition, storage conditions and fruit commodity. Currently, there are several coatings commercially available for postharvest use. However, lack of knowledge about composition makes difficult to predict performance on fruit. There is a need to study the effect of coating composition on postharvest quality of specific commodities. The objective of this work was to study the effect of lipid type and amount on performance of hydroxypropyl methylcellulose (HPMC)–lipid composite coatings on weight loss and texture of plums cv. Autumn Giant. Beeswax and Shellac were selected as the hydrophobic phase at 20% and 60% (d.b.). Stearic acid, glycerol and lipid were added to the HPMC suspension, and the mixture was homogenized to get uniformly-dispersed emulsion. Plums were dip-coated, either with edible coating or water-dipped, following by air-drying. One group remained uncoated as control. Plums were stored in this sequence: 6 weeks at 1ºC, 3 days at 6ºC, and 1 day at 20ºC. Storage time at 20ºC was also prolonged up to 16 days. Weight loss and texture of plums were measured during storage. As expected, weight loss decreased as lipid content increased. No differences on weight loss were observed between uncoated and 20% lipid-coated plums. Water-dipped plums presented the higher weight loss. In general, there were no differences on weight loss between lipid type. Fruit texture was not affected by coating after short-term storage at 20ºC. However, for prolonged storage at 20ºC, coatings improved texture significantly. Whereas, uncoated and water-dipped plums were considered unmarketable. Results indicate that natural waxes of plums are as effective as coatings having 20% lipid for short-term storage at 20ºC, but these coatings improved plum quality for prolonged store.
Session 76C, Fruit & Vegetable Product: Fresh Fruits and Vegetables
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