QUALITY ATTRIBUTES OF STARCH COATED REFRIGERATED STRAWBERRIES (FRAGARIA × ANANASSA)

摘要

Edible coatings prolong the storage life of vegetables delaying post-harvest metabolism. Starch-based coatings were applied on strawberries (Fragaria × ananassa) stored at 0°C. Effects of coating formulation including starch type, plasticizer, lipid and antimicrobial agent were analyzed. Film microstructure was characterized by Scanning Electron Microscopy, Differential Scanning Calorimetry and X ray diffraction; barrier properties were also determined. Plasticizer addition was necessary to maintain film integrity being sorbitol the most effective. The addition of sunflower oil to the formulations decreased water vapor permeability of coatings. Differential gaseous permeabilities to CO{sub}2 and O{sub}2 modified the internal atmosphere of fruits delaying senescence. Modifications of physiological parameters in strawberries were slowed down for coated strawberries. Coated fruits showed lower weight losses and maintained surface color of the strawberries. The addition of antimicrobial agents (citric acid and potassium sorbate) decreased microbial growth, and extended storage time of the coated fruits to 28 days, doubling that of the control samples.