PLASTICIZED STARCH-BASED COATINGS TO IMPROVE STRAWBERRY (FRAGARIA X ANANASSA) QUALITY AND STABILITY

Starch-based coatings were applied to extend storage life of strawberr ies (Fragaria x ananassa) stored at 0 degrees C and 84.8% relative hum idity. The effects of amylose content of the starch, the type of plast icizer (glycerol and sorbitol), and the inclusion of antimicrobial age nts on coating formulation were analyzed. Microstructure characterizat ion of coatings was related to water vapor permeability (WVP) observat ions. Coatings made with starches with the higher amylose content decr eased WVP and weight losses and retained fruit firmness for longer per iods than coatings formulated with medium amylose content starches. Co atings with sorbitol showed lower WVPs than glycerol ones. Both sorbit ol and glycerol reduced weight losses and maintained texture and surfa ce color of fruits, with 20 g/L sorbitol being the most effective plas ticizer option, Modifications of physiological parameters in strawberr ies such as anthocyanin content, reducing and nonreducing sugars, titr atable acidity, and pH were slowed for coated fruits. The formulations with potassium sorbate reduced microbial counts, extending strawberry storage life from 14 days (for control fruits) to 28 days in coated s trawberries. The addition of citric acid enhanced antimicrobial action of potassium sorbate.