Conclusion
The highest betacyanin content was observed when 0.25 %
(w/w) ascorbic acid was added to red-fleshed dragon fruit
juice and the juice was adjusted to pH 4 and pasteurized at
65 °C for 30 min. Betacyanin juice was found to deteriorate at
the agitation speed of 220 rpm. The addition of 0.25 % (w/w)
ascorbic acid helped to stabilize betacyanin in both juice and
concentrate stored under agitated or non-agitated conditions.
Light was also found to degrade betacyanin. In juice samples,
dark storage resulted in higher betacyanin content. There was
no difference in betacyanin content of concentrate samples
stored in dark or light. The addition of 0.25 % (w/w) ascorbic
acid shows a stabilizing effect on betacyanin of concentrate
samples that were stored in light.