Abstract
Roselle (Hibiscus sabdariffa L.) is an annual shrub popularly grown in tropical and subtropical areas. Although Roselle fruit has been used for a long time as a herbal tea due to its high content of bioactive compounds like phenolic acids and anthocyanins, the studies on the effects of the drying process and brewing conditions on the content of beneficial components and bioactivities of Roselle tea is limited. In this study, the influence of drying temperature on the retention of total phenolic content (TPC) and antioxidant capacity (AC) of the dried Roselle and the effects of brewing conditions including water temperature, liquid-solid ratio and brewing time on total soluble solid (TSS) content, total phenolic content, and antioxidant capacity of Roselle tea were investigated. The drying at 80 °C produced the dried Roselle with the highest retention of TPC (25.196 mg GAE/g) and AC (IC50 of 2.2 mg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition) and the highest sensory quality compared to the drying at other temperatures. The brewing process using hot water at 90 °C with the solid-liquid ratio of 1:10 (g/mL) for 30 min resulted in the highest TSS content (5.4 oBx), TPC (12.7 mg GAE/g dried Roselle) and AC (73.3% DPPH inhibition) of the Roselle tea. Thus, the drying at 80 °C combined with the brewing of dried Roselle for 30 min using 90 °C hot water with the solid-liquid ratio of 1:10 (g/mL) are recommended to produce Roselle tea with the highest content of beneficial ingredients.
Highlights
Roselle (Hibiscus sabdariffa L.) is an annual shrub belongs to the Malvaceae family and mostly grows in tropical and subtropical areas like African and Asian countries [1]
With the solid-liquid ratio of 1:10 (g/mL) for 30 min resulted in the highest total soluble solid (TSS) content (5.4 o Bx), total phenolic content (TPC) (12.7 mg gallic acid equivalent (mg GAE)/g dried Roselle) and antioxidant capacity (AC) (73.3% DPPH inhibition) of the Roselle tea
The drying at 80 ◦ C combined with the brewing of dried Roselle for 30 min using 90 ◦ C hot water with the solid-liquid ratio of 1:10 (g/mL) are recommended to produce Roselle tea with the highest content of beneficial ingredients
Summary
Roselle (Hibiscus sabdariffa L.) is an annual shrub belongs to the Malvaceae family and mostly grows in tropical and subtropical areas like African and Asian countries [1]. Previous studies have demonstrated that drying, an essential thermal process in producing herbal teas, may cause significant losses of bioactive ingredients and thereby decrease the health benefits and quality of the products [10,11]. The brewing conditions such as quality, volume, and temperature of water and brewing time have been reported to significantly affect the content of the desired components in tea infusion [12,13]. The results help to suggest a convenient procedure of drying, along with brewing, which can be used at household or small scale to produce high-quality Roselle tea
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
