Postharvest Quality of Shattered Grapes Coated with Chitosan and Stored under Refrigeration

The main problems of postharvest preservation of fine table grapes are the rotting, the dehydration of the stalk, the browning and shattering of the berries, causing losses and impairing the quality of the products. Aiming to improve the use of shattered grape berries, and consequently the producer’s income, the present study evaluated the postharvest quality of fine table grapes of different varieties of Vitis vinifera L., shattered berries, coated with different concentrations of chitosan and stored for 56 days under refrigeration. The experiment was conducted in a completely randomized design in a factorial arrangement consisting of three factors: cultivars (Italy and Rubi), chitosan concentrations (control, 0.5%, 1.0% and 1.5%) and conservation periods (0, 7, 14, 21, 28, 35, 42, 49 and 56 days), with four replications. Physical and chemical analyses were carried out every seven days. The physical analysis considered the weight loss, color, rot incidence and appearance of the fruit. Chemical analyses evaluated the levels of soluble solids (SS), titratable acidity (TA), ratio (SS/TA) vitamin C and pH. The coating with chitosan has increased the shelf life by up to 14 days for both cultivars, with the best results observed with grapes treated with 1.5% chitosan for cv. Rubi, and chitosan at 1.0 and 1.5% for cv. Italy.