Antioxidant capacity and sensory evaluation of soursop leaves tea incorporated with dried fruit pulps

Soursop leaves tea contains antioxidant capacity; however, it is not readily acceptable due to its aroma, flavour, and taste. The present work thus assessed whether incorporating dried fruit pulps into soursop leaves tea could enhance its antioxidant capacity and sensory acceptability. The soursop leaves were processed using green tea processing method, and dried at 70°C until 5% moisture content was obtained. The soursop leaves tea was incorporated independently with dried soursop pulps, dried pineapple pulps, and dried key lime at a ratio of 2:1, and brewed at 70°C for 10 min. The dried fruit pulps were processed at 60°C until the moisture content was 9 to 18%. The physicochemical properties (pH and colour characteristics) of the brewed soursop leaves tea (SL), soursop leaves tea incorporated with dried soursop pulps (SLS), soursop leaves tea incorporated with dried pineapple pulps (SLP), and soursop leaves tea incorporated with dried key lime (SLK) were analysed using pH meter and colorimeter. The results showed that SLK had the lowest lightness and pH value. The colour of the brewed samples was all in the range of yellowish green. The antioxidant capacity, total phenolic content (TPC), and total flavonoid content (TFC) analyses of the brewed samples were conducted by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, Folin-Ciocalteu method, and aluminium chloride colorimetric method, respectively: SLP had the highest antioxidant capacity of 94.69 ± 0.50%, while SLK had the highest TPC (0.46 ± 0.01 mg GAE/mL). However, statistical data of TPC showed no significant difference between SLK and SLP. Meanwhile, SL had the highest TFC (34.85 ± 0.17 mg QE/mL). The sensory evaluation results reported that SLP had the highest acceptability of “like slightly” (6.00 ± 1.77). In conclusion, SLP had the highest antioxidant capacity, panellist acceptability, and considerably high TPC.