Investigating the influence of drying temperature on the flavonoid profile, quercetin content, and antioxidant activity in dayak onion

Arsianti, Rika Wahyuni
Argo, Bambang Dwi

Advances in Food Science, Sustainable Agriculture and Agroindustrial Engineering (AFSSAAE)
Vol 8, No 3 (2025)

As a traditional medicinal plant rich in flavonoids, Dayak onion (Eleutherine bulbosa) has great potential as a functional food. However, its high water content requires a proper drying process to maintain its bioactive compounds. This study evaluated the effects of oven drying temperatures 40°C, 50°C, and 60°C on the total flavonoid content (TFC), quercetin levels, and antioxidant activity of Dayak onion. Samples were dried to a target moisture content of 12% and analyzed using UV-Vis spectrophotometry, HPLC, and the DPPH method. The results showed a positive linear relationship between drying temperature and phytochemical quality. 60°C was the most effective condition, increasing TFC from 45.05 mg/L to 101.42 mg/L (2.25-fold), quercetin levels from 9.13 ppm to 17.51 ppm (1.91-fold), and significantly increasing antioxidant activity (decrease in IC₅₀ value). Thus, controlled drying at 60°C is an effective method to improve the quality and functional value of Dayak onions.