Microencapsulation of betacyanin from red dragon fruit (Hylocereus polyrhizus) peels using pectin by simple coacervation to enhance stability

Abstract

Betacyanin is a red natural dye pigment widely used in food products. However, the pigment is also unstable and easily degraded by temperature during storage and food processing. This research aims to increase the stability of betacyanin obtained from dragon fruit peels using pectin as a wall medium via the coacervation method. Due to the efficiency and shell integrity, the coacervation method was selected instead of spray drying to enhance betacyanin’s stability. Coacervation was conducted in a three-necked round-bottomed flask fitted with a mercury-sealed stirrer and reflux condenser. An accelerated stability test was conducted at 80 C and 100 C for 30 min and considered completed after obtaining a stable absorbance. Two full factorials, three-level design, for 80 C and 100 C, were analyzed by Response Surface Methodology using Minitab 19. The core/wall ratio, agitation speed, and pH were the continuous variables, with temperature as the categorical variables. The models were yielded high R-square and low coefficient of variance on the validation process. Simple coacervation is selected because of a superior method such as simplicity, low-cost, high efficiency, and high shell integrity.