Optimization of methanol-water solvent extraction of anthocyanins from Roselle (Hibiscus sabdariffa L.) petals using response surface methodology

Anthocyanins, a prominent group of water-soluble plant pigments, exhibit noteworthy health-promoting properties and are natural colorants in food applications. this study aimed to optimize the solvent extraction of anthocyanins from roselle petals using methanol-water solvent, with three independent variables: extraction time (2 to 6 h), extraction temperature (20 to 40⁰c), and roselle petal to solvent weight ratio (2 to 6 g). response surface methodology (rsm) based on box-behnken design (bbd) was employed for experimental design. the anthocyanin content extracted from roselle petals ranged from 132.85 to 270.49 mg/l. elevated extraction temperature, extended extraction time, and higher petal-to-solvent ratio significantly enhanced anthocyanin extraction efficiency (p≤0.05). the optimal conditions for maximum anthocyanin extraction were predicted as follows: extraction temperature of 40⁰c, extraction time of 5.71 h, and petal-to-solvent ratio of 6. under these conditions, 266.19 mg/l of anthocyanin was extracted, validating the model prediction (r2=0.96).