INFLUENCE OF GUAR GUM – GLYCEROL COMPOSITE COATINGS ON POSTHARVEST QUALITY AND SHELF-LIFE EXTENSION OF DRAGON FRUIT STORED AT REFRIGERATED TEMPERATURE (8° C)

–This study reported the effects of guar gum-glycerol based edible coatings on the physico-chemical properties and shelf life of red dragon fruit (Hylocereus spp.) stored at refrigerated temperature (8 oC). Dragon fruits were coated with different concentration of guar gum and glycerol (1%, 2%, 3%) based coatings compared to uncoated control fruits. Physiological loss in weight (PLW), firmness, total soluble solids (TSS), Titrable acidity, pH and shelf life were evaluated at regular intervals during storage. Coated fruits exhibited lower PLW and better retention of firmness compared to uncoated control. The T3 treatment showed least changes in PLW (0.29% to 5.78%), firmness (5.9 to 4.1 kg/cm2 ), TSS (10.3 to 11.4 Brix° ), acidity (0.42% to 0.27%), and pH (4.36 to 4.74) during the 30-day storage period. T3 coated fruits also had the longest shelf life of 32 days, followed by T2 (29 days), T1 (28 days), and uncoated control (26 days). The results demonstrate that guar gum- glycerol composite coatings at 3% concentration can effectively improve the quality and enhances the shelf life of red dragon fruit at refrigerated temperature.