Nowadays, the trends in human health and fossil fuel dependent markets present opportunities for agricultural crops as renewable sources in several substitutes of synthetic components in clothing, fuels, and food. This research focused on anthocyanins along with protocatechuic acid and quercetin, which have been recognized as bioactive compounds in Hibiscus sabdariffa L. aqueous extracts. Laboratory extraction study was conducted on various solvent concentration, liquid-solid ratio, temperatures and time values on the extraction yield of anthocyanin from Vietnam Hibiscus sabdariffa L. (Roselle). On theother hand, total anthocyanins wereinvestigated in Hibiscus sabdariffa L. extract as μg/mL cyanidin-3-glucoside (cyd-3-glu). Extraction temperature of 60°C using solvent concentration 50%, extraction time of 30 min at liquid-solid ratio of 8:1 showed the highest anthocyanin recovery at 180,821 mg/L. Overall, Vietnam Hibiscus sabdariffa L. (Roselle) are responsive to anthocyanin extraction, making it an appropriate substrate for the development of industrial colorants and dyes.

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Hibiscus sabdariffa L. (Hs, roselle; Malvaceae) is a common ingredient used in the food and pharmaceutical industries for color and health benefits. Anthocyanins along with protocatechuic acid and quercetin have been recognized as bioactive compounds in Hibiscussabdariffa L. aqueous extracts. In this work, Response Surface Methodology was implemented together with Box-Behnken experimental design to investigate the impacts of process variables on anthocyanin extraction yields from Hibiscus sabdariffa L. (Roselle) grown in Lam Dong, Vietnam. The effects of three independent variables; namely the extraction temperatures of solvent ethanol (X1); the duration of extraction (X2); solid-liquid ratios (X3) on the total anthocyanins content (Y1) were explored. The optimization model showed that with the solid liquid ratio 7.7:1, extraction time 33.29 min, and temperature 56.9°C, the highest anthocyanin concentration of 186.006 mg/L was obtained. Hibiscussabdariffa L. anthocyanin yield detailed significant correlation with high F values, low P values (<0.0001), and desirable determination coefficient (R2 = 0.9770). The resulting quadratic model could be used to predict yields with given conditions. Actual experimental verification and residual testing revealed that the actual anthocyanin yields could be accurately predicted by the model.

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