Bioaccessibility of Antioxidant Capacity of Wedang Uwuh a Traditional Indonesian Beverage by Gastrointestinal Digestion

Abstract

Wedang uwuh is a traditional Indonesian beverage that contains natural antioxidants. Hence, it is generally consumed by people to get health benefits. The antioxidant compounds can exert their activity only after passing through the digestive system. This study aims to determine the impact of boiling time on the antioxidant bioaccessibility of wedang uwuh beverages after passing through digestive process, which are gastric and intestinal stages. The antioxidant bioaccessibility was evaluated using the bioaccessibility index (BI) of antioxidant capacity (FRAP, DPPH, and ABTS assay) and the bioaccessibility of phenolic content was also measured using total phenolic content (folin–ciocalteu method). The research found that lengthening of boiling time could increase significantly (p<0.05) number of phenolic content, as well as antioxidant capacity. The 15 minutes of boiling resulted in the highest phenolic content and antioxidant capacity before digestion. Otherwise, after wedang uwuh beverage passes through gastric and intestinal digestion, boiling for 5 minutes resulted in the highest phenolic content and capacity of antioxidants. This was due to heat processing influencing the stability of phenolic and antioxidant compounds before and after digestion. The bioaccessibility of antioxidant and phenolic compounds in wedang uwuh beverage was higher in the 5 minutes boiling process than in the 15 minutes. The boiling process for 5 minutes resulted in the bioaccessibility index of wedang uwuh beverage were 32.25% for total phenolic content, 37.25% for FRAP, 25.88% for scavenging of radical DPPH• and 83.45% for scavenging of radical ionic ABTS•+. Hence, it was recommended to use a boiling time of 5 minutes to prepare a wedang uwuh beverage. This study found that pH conditions and enzymatic activity in gastrointestinal digestion decreased phenolic and antioxidant contents.