Optimization infusion condition on flavonoid and antioxidant activity of herb beverages using response surface methodology

Abstract

Herbs have potential to be developed as functional beverages to reduce the risk of Covid-19 infection. One of herb ready to serve form is brewed in a bag. This study optimizes the conditions for herb beverages infusion in a silk bag based on their flavonoid content and antioxidant activity. Optimization is completed using the Response Surface Methodology with 33 Central Composite Design models. As the factor X1 is the mass of the herbs in the bag, X2 is the infusion frequency and X3 is the steeping time. Each factor consists of 3 levels. The flavonoid content was determined using the UV-Vis spectrophotometric method. The antioxidant activity was measured based on the DPPH free radical scavenging capacity. The results of this study indicate that the optimal condition is achieved in the herb mass of 1.2 g with an infusion frequency of 18 times and steeping time for 15 minutes. Flavonoids content and antioxidant activity in herb beverages at optimal infusion conditions were 942,353 μg QE / mL (117.79 mg QE / g) and 83.06%, respectively.