Optimisation of Processing Parameters for the Production of Hibiscus Flower Extract Beverage With Enhanced Bioactive Content in Kano State, North West Nigeria

Hibiscus sabdariffa, locally known as zobo in Nigeria, is among the most widely consumed beverages in the country and is valued for its anthocyanin content and purported antioxidant and antihypertensive properties. Optimisation of extraction parameters to maximise bioactive retention while ensuring consumer acceptability represents a critical research gap. This study optimised processing parameters for the production of hibiscus flower extract beverage with enhanced bioactive content in Kano State, North West Nigeria. A response surface methodology-based experimental design was applied, varying extraction time, temperature, and water-to-calyx ratio across experimental runs. Response variables included anthocyanin content, total phenolic content, antioxidant activity by DPPH assay, colour intensity, titratable acidity, pH, and sensory acceptability. Data were analysed using analysis of variance and regression modelling via Design-Expert software. Results showed that extraction at 80 degrees Celsius for 15 minutes at a 1:10 calyx-to-water ratio yielded optimal anthocyanin and total phenolic content without significantly compromising sensory acceptability. Higher temperatures and prolonged extraction times caused anthocyanin degradation. Sensory panellists preferred samples extracted at moderate temperatures with balanced acidity. The study recommends the identified optimal parameters for small and medium enterprise hibiscus beverage production, with further research exploring natural preservation to extend shelf life. Keywords: hibiscus, zobo beverage, anthocyanin, response surface methodology, Kano State