Postharvest application of hot water and ultraviolet light prolongs the marketable window of fresh grapes by maintaining physicochemical attributes during ambient storage
Experimental study reveals hot water and UV-C light preserve quality and extend shelf life in Sultana grapes, indicating an effective chemical-free preservation strategy.
Key Points
Evaluate the efficacy of combined hot water treatment and UV-C radiation as a non-chemical method to preserve quality and extend the shelf life of Sultana grapes during ambient storage.
Freshly harvested Sultana grape bunches received hot water treatment (HWT) followed by UV-C light exposure and were stored at room temperature (25 ± 1.5°C) alongside untreated controls for 7 days.
Physicochemical attributes, oxidative stress indicators, antioxidant enzyme activities, and marketability were evaluated using a completely randomized two-factor factorial design.
On day 7, HWT + UV-C treated grapes showed approximately 13.3% higher firmness, 6.5% lower weight loss, 11.3% lower electrolyte leakage, and a 19.7% increase in marketable fruit compared to controls.
Treatment reduced oxidative stress markers by roughly 85% for superoxide anions and 50.8% for hydrogen peroxide, which was associated with increased activity of antioxidant enzymes (superoxide dismutase, catalase, peroxidase, ascorbate peroxidase) and greater retention of phenolics, chlorophyll, and ascorbic acid.