Eco-safe hot water dip alleviates antioxidant level and sensory quality of Indian jujube fruits

Abstract

Indian jujube (Ber) is highly perishable climacteric fruit owing to high decay index limiting its marketability and demands interventions to prolong shelf life. Fungicides are normally used to control rot during postharvest storage, however, residues left necessitate eco-safe alternatives like hot water dipping. Mature, pre-climacteric jujubes were dipped in 45, 50 or 55 °C water for 8, 6 or 4 min, respectively and then stored at 5 °C for periodic quality evaluation. Dipping fruits in 55 °C water resulted in 32.69 and 35.27, 64.21 and 58.57, 30.41 and 30.42, 38.50 and 52.20 % lower weight loss, decay index, malondialdehyde (MDA) and electrolyte leakage, whereas 15.40 and 16.77, 19.51 and 20.48 % greater antioxidant activity and ascorbic acid respectively for Umran and Pakwhite compared to 25 °C water dip. The highest glucose, fructose, malic, citric, and tartaric acids were 23.44 ± 1.04 and 29.9 ± 0.95, 30.68 ± 1.72 and 41.17 ± 2.34 mg/100 g, 138.1 ± 6.45 and 112.97 ± 6.16, 57.49 ± 1.71 and 53.78 ± 1.90, 79.58 ± 5.1 and 65.3 ± 4.83 μg/100 g whereas lower sucrose 12.34 ± 0.94 and 16.33 ± 1.05 mg/100 g were respectively recorded in 55 °C water dipped Umran and Pakwhite fruits. High dip water temperature (55 °C) exhibited better quality with the lowest decay index and weight loss, greater membrane integrity, bioactives content and sensory acceptance scores. Hence, hot water dipping was shown to be an effective residue-free option to extend the marketable period of jujubes to capture distant markets.