Xanthan Gum-Based Edible Coating Enriched with Grape Stalk Extract for Enhancing the Storability of Grapes (Vitis vinífera L. Cv. Thompson Seedless) under Ambient Conditions

This research aimed to develop an edible coating based on xanthan gum incorporated with grape stalk extract (GSE) with varying concentrations (5–25%) and evaluate its potential to enhance the storability of white grapes under ambient conditions. The GSE demonstrated a high phenolic content (259.81 mg GAE/g) and flavonoids (16.52 mg QE/g) as well as excellent antioxidant activity (95.73%). The edible coating incorporated with a GSE content of 25% (XG-GSE-25) demonstrated excellent phenolic and antioxidant activity. The application of edible coating on white grapes retained the quality attributes during storage at ambient conditions such as reduced weight loss (24.97%) control with minimal changes in puncture strength (∼20%), titratable acidity (∼22%), total soluble solids (∼19%), ascorbic acid content (∼17%), membrane electrolytic leakage (∼36%), respiration rate (∼2.4 mg CO₂ kg^–1 h^–1), and color attributes as compared to control up to 16 days. Further, the developed coating with high GSE concentration was effective in retaining the phenols, flavonoids, and antioxidant activity of grapes compared to that of uncoated grapes.