Application of edible coatings for extending shelf life of fresh strawberries

Abstract:

The old adage that strawberries begin dying the moment they are picked isn't far from the truth—the fruit's high respiration rate, thin skin, and susceptibility to Botrytis cinerea limit its post-harvest shelf life to just 3 to 5 days at ambient temperature. Edible coatings that form a semi-permeable barrier around the fruit surface can slow moisture loss, reduce gas exchange, and inhibit microbial growth. This research evaluated four edible coating formulations—chitosan (1%), aloe vera gel (2%), guar gum (1.5%), and a chitosan + aloe vera composite—on quality retention of cv. Winter Dawn strawberries stored at 4 ± 1 °C for 12 days at the post-harvest laboratory of Sardarkrushinagar Dantiwada Agricultural University, Gujarat. The chitosan + aloe vera composite maintained the highest firmness (4.3 N), lowest weight loss (3.7%), and lowest decay incidence (8.4%) at day 12 compared with the uncoated control (2.1 N, 11.8% weight loss, 34.6% decay). Ascorbic acid retention was 78.3 percent under the composite coating versus 51.2 percent in uncoated fruit. Total soluble solids and titratable acidity changes were also slower under coated treatments. Chitosan alone was the second-best option, while guar gum showed the weakest performance. These results indicate that a chitosan-aloe vera composite coating can extend the marketable shelf life of strawberries from 5 to 12 days under refrigerated storage.