Roselle calyces (Hibiscus sabdariffa) pigment contains an inexpensive source of anthocyanins, which is used as a natural colourant in food preparation instead of artificial colours. Hence, a study was carried out to extract anthocyanin from roselle calyces using acidified ethanol. The pigment stability during storage under different temperature conditions was also investigated. Kinetics study of the roselle extract was conducted to find out the degradation rate. It was concluded that the pigment stored in amber bottle under refrigerated conditions showed least degradation rate with the k value of 0.0017, followed by transparent bottle in refrigerated conditions with a k value of 0.0025. The highest degradation rate was found when pigment was stored in transparent bottle at 40℃ under light with a k value of 0.0055. The half-life periods of the pigment extract stored in amber bottle and transparent bottle under refrigerated condition (10℃), dark and light condition at 40℃ were 407.73, 277.25, 223.59, 138.62, 147.47 and 126.02 days respectively. From the results of the experiments, it was found that roselle calyces (Hibiscus sabdariffa) is a potential source of natural anthocyanin which can be used as a natural colourant in various food formulations.
Keywords: Hibiscus Sabdariffa (Roselle), Anthocyanin, optimization, Calyx, Ethanol Extraction, kinetics study, half -life period.
Key words: Hibiscus Sabdariffa (Roselle), Anthocyanin, optimization, Calyx, Ethanol Extraction, kinetics study, half -life period.
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