| Abstrak/Abstract |
Betacyanins have been reported to provide prominent health-promoting effects, in addition
to contributing to the exotic color and pleasant palate of red dragon fruit that has been attracting
universal interest for over a decade. An accurate determination of betacyanins in dragon fruit is
important if we are to benefit from the nutraceutical features of these compounds. Seven betacyanin
pigments have been identified and extracted by means of ultrasound-assisted techniques from red
dragon fruit. Chemometric tools such as Box–Behnken Design (BBD) in conjunction with response
surface methodology (RSM) have been successfully used to evaluate and optimize the relevant
extraction variables i.e., temperature (A: 10, 35, 60 ?C), solvent composition (B: 20, 50, 80% methanol
in water), sample to solvent ratio (C: 0.1:10, 0.2:10, 0.3:10 g/mL), power (D: 20, 45, 70%), and cycle
(E: 0.3, 0.5, 0.7 s?1). The results obtained from the analysis of variance (ANOVA) suggest that the
solvent composition (p 0.0063), sample to solvent ratio (p 0.0126), and cycle (p 0.0302) are the most
influential variables in betacyanin extraction. The optimal variable settings for ultrasound-assisted
extraction (UAE) were a 54.6 ?C extraction temperature, 0.3 s?1 cycle, 20% ultrasound power, 21.4%
methanol in water solvent composition, 0.2:10 sample to solvent ratio, and a 5 min extraction time.
The validation of the method for repeatability and intermediate precision provided excellent results
at 1.56% and 2.94% respectively. Furthermore, the novel UAE method was successfully used for the
determination of betacyanins content in red dragon fruit from different geographic origins. |
