USING FRUIT PEEL EXTRACT IN PITAYA JAM MAKING (Hylocereus undatus)

Abstract

Pitaya (Hylocereus undatus), also known as dragon fruit, is the most popular species cultured in Vietnam. The fruit is a fleshy berry with a mild sweet taste blended and touch of sourness, white pulp embedded with many edible black seeds, and reddish-purple peels whose extract could be used as a natural food colorant. Extraction of pitaya fruit peels is an alternative to using food waste. This study aims to determine the effects of fruit peels on the pitaya jam process. Herein, the peels were extracted by two methods including blending and extraction, then optimized along with other conditions such as the extract contents (10, 30, 50%), pectin concentrations (0,9, 1,2, 1,5%), sugar contents (60, 64, and 68°Bx), temperatures (50, 60, 70°C), and heating times (5, 10, and 15 min). The results showed that, peel extraction in water at 100℃ produced a red jam with a high concentration of betacyanin. Pitaya fruit jam was successfully obtained in the optimized conditions of 30% fruit peel extract, 1.2% pectin, 64°Bx, 60°C, and 10 minutes of heating time. The dragon fruit jam has good quality viscosity, with the reddish-purple color of the fruit peels, natural aroma, and taste.