Improvement of quality and shelf-life of strawberries with edible coatings enriched with chitosan

Strawberry fruit have a very short shelf-life and senescent period due to their high degree of perishability and infection caused by several pathogens that can rapidly reduce fruit quality. The aim of this study was to determine the efficacy of carboxymethyl cellulose (CMC), hydroxypropylmethyl cellulose (HPMC) and composites with chitosan (CH) coatings on the shelf-life and overall quality of strawberry fruit. Strawberry fruit dipped for 2 min in solutions of CMC (1%), HPMC (1%), CMC (1%) + CH (1%) and HPMC (1%) + CH (1%) were stored at 11 +/- 1 degrees C, 70-75% RH, while the uncoated fruit served as controls. Fruit coated with edible coatings showed significant delays in the change of weight loss, decay percentage, titratable acidity (TA), pH, total soluble solids (TSS) and ascorbic acid content as compared to uncoated control fruit. In addition, the edible coatings had a positive effect on maintaining higher concentrations of total phenolics and total anthocyanins, which decreased in control fruit due to over-ripening and senescence processes. Compared to the controls, all the coatings had positive effects on the inhibition of cell wall degrading enzymes and among all the tested coatings, CMC + CH and HPMC + CH was superior in inhibiting enzyme activity. These findings suggest that the use of CMC 1% + CH 1% and HPMC 1% + CH 1% coatings are useful for extending the shelf-life and maintaing quality of strawberry fruit. (c) 2013 Elsevier B.V. All rights reserved.