Efficiency and thermal stability of encapsulated anthocyanins from red dragon fruit (Hylocereus polyrhizus (Weber) Britton & Rose) using microwave-assisted technique

Abstract

Anthocyanins are one of the commonly used natural colorants for beverages, confectionary, fruit preparation and ice cream. Strong antioxidant activity of these anthocyanins has attracted great interest to the food industry. The instability of anthocyanins through the factors such as light, pH, temperature and oxygen has given problem during processing and storage of these compounds. One of the approaches to overcome this problem is by encapsulating the material using wall material. This study was conducted to investigate the efficiency of encapsulation of anthocyanins from red dragon fruit (Hylocereus polyrhizus (Weber) Britton & Rose) using microwave-assisted technique with different drying times and thermal stability of the encapsulated anthocyanins. Encapsulated anthocyanins were produced in form of powder using maltodextrin as the wall material. The encapsulation drying time were varied from 1 min to 3 min with fixed power, 330W. The encapsulated anthocyanins were analyzed in effect of thermal heating (60°C and 80°C). The results indicated that, at different encapsulation drying time, 2 min capsule showed the highest yield of encapsulation where 3 min capsule showed the highest encapsulation efficiency followed by 2 min capsule with 4% differences. From this study the encapsulation at 2 min drying time showed the most feasible encapsulation process. Thermal study at 60°C and 80°C showed that anthocyanins degraded faster at higher temperature, 80°C for all capsule types.