Formulation and characterization of an optimized functional beverage from hibiscus (Hibiscus sabdariffa L.) and green tea (Camellia sinensis L.).

Hibiscus sabdariffa and Camellia sinensis are traditionally consumed as beverages and are good sources of health-promoting phenolic compounds. The objective of this work was to use response surface methodology to develop an optimized functional beverage with high total phenolic content, antioxidant capacity, and acceptable for potential consumers. Optimum infusion conditions were 4.9 g of hibiscus calyces or C. sinensis leaves/100 ml of water at 26 ℃ for 291 min. These conditions yielded a total phenolic content of 14.80 ± 1.4 and 33.02 ± 0.34 mg gallic acid equivalents/100 ml for hibiscus and green tea, respectively. The optimized beverages were combined in a 7:3 (hibiscus:green tea, v/v) ratio; a consumer preference test showed that this combination had an acceptable taste according to untrained panelists. A chromatographic analysis showed that this formulation contained flavonoids, phenolic acids, and anthocyanins as its main components. Our data suggested that hibiscus and green tea phenolic compounds were efficiently extracted using near-ambient temperature water for prolonged times, contrary to routine methods (high temperature, short time). Our method also preserved antioxidant capacity, possibly by avoiding chemical changes/degradation due to high temperatures. This process can be used to produce organoleptically acceptable functional beverages that deliver a varied phenolic compound profile to the consumer.