Comparison of ultrasound assisted extraction and enzyme assisted extraction of betacyanin from red dragon fruit peel

This article was intended to extract betacyanin from the peel of red dragon fruit (Hylocereus polyrhizus) and used it as a natural colorant. In this study, enzyme and ultrasound techniques for the extraction of betacyanin from dried dragon fruit peel were compared. The ultrasonic power and sonication time levels were varied between 0.5, 1.5, 2.5, 3.5, and 4.5 W/g; and 2.5, 5.0, 7.5, 10.0, and 12.5 min. The enzyme concentrations were 0.25, 0.75, 1.25, 1.75, 2.25, and 2.75 %v/w. The results revealed that the maximum betacyanin content obtained by the optimal UAE condition (3.5 W/g and 7.5 min) was 0.3402 mg/g, and 9.47 % higher than that by the EAE method. The first- order kinetic extraction was used to describe the mechanism of extraction of betacyanin from red dragon fruit peels. The initial extraction rate (h) and extraction rate constant (k) of the UAE model were 30.80 and 27.81 % higher than those of the enzyme assisted extraction (EAE) model. The UAE treated only 5.0 min to obtain the highest level of betacyanin (0.323 mg/g), whereas the EAE took up to 20 min to achieve the maximal value (0.309 mg/g). The research clearly shows that the UAE method is a useful method for extracting betacyanin from dried red dragon fruit peel.