Effect of Waste Green Algal Biomass Extract Incorporated Chitosan-Based Edible Coating on the Shelf Life and Quality Attributes of Tomato

A de-oiled crude green algal ethanolic extract (CAEE) incorporated chitosan (CS)-based edible coating material was formulated and applied on red tomatoes, aiming to minimize postharvest loss and prolonging the shelf life with improved quality attributes. The waste biomass of Dunaliella tertiolecta was subjected to ultrasound-assisted solid-liquid extraction for obtaining an antioxidant-rich extract. Response surface methodology was used for optimizing the process of extraction. The coating materials were developed by mixing the aqueous CS (1 wt %) solution in mild acetic acid medium (0.3% v/v) with CAEE at varying concentrations (0, 2, and 4% w/v). Millipore water was used as a control coating material for drawing the comparison. The coated and control tomatoes were stored for 30 days under ambient conditions (27-30 degrees C and 60-70% RH). The results indicated that the tomatoes coated with CS/CAEE 4% coating formulation exhibited superior effectiveness for extending the shelf life with improved physicochemical properties such as DPPH antioxidant activity; reducing sugar, lycopene, and ascorbic acid contents; and firmness by restricting faster respiration and ripening rates during ambient storage.