EFFECT OF INFRARED DRYING TEMPERATURE AND STORAGE TIME ON THE QUALITY ATTRIBUTES OF JELLY MADE FROM RED-FLESHED DRAGON FRUIT (Hylocereus polyrhizus)

Abstract

Red dragon fruit (Hylocereus polyrhizus) is a popular tropical fruit known for its distinctive shape, vibrant color and high nutritional value, including vitamins A, C and B-group vitamins, as well as pigments and antioxidants such as phenolics, flavonoids and betalains. However, convection-dried dragon fruit products have disadvantages, such as poor flavor control, color loss and a lack of characteristic aroma. This study was conducted to investigate the effects of infrared drying temperatures (50, 55, 60°C) on the quality changes of red-fleshed dragon fruit – pineapple jelly based on restructuring technology using agar as the gelling agent. The aim was to enhance aroma, reduce color changes and maintain flavor during storage (0, 7, 14, 21, 28 days). The results showed that when the jelly was dried at 55°C and stored for 21 days, its quality remained stable, with a water activity (aw) of 0.57, betacyanin content of 281.97 mg/kg, vitamin C content of 587.79 mg/kg and total phenolic content (TPC) of 1223.63 mg GAE/kg. The color values were L (19.80), a (49.09) and ΔE (15.68), indicating significant color differences between day 0 and day 21. These findings suggest that infrared drying holds potential for jelly production, helping to maintain product quality during storage.