Optimization of extraction conditions of flavonoids from Houttuynia cordata Thumb leaves

Abstract

This study was conducted to investigate the application of cellulase enzyme in the extraction of flavonoids from Houttuynia cordata Thumb leaves and optimize the extraction conditions. Independent variables, including enzyme concentration (25 - 100 µg/mL), temperature (30 - 50oC), time (30 - 120 min) and ratio of raw materials to enzyme (1:15 - 1:30 g/mL), were investigated. Extraction conditions of flavonoids were designed according to Central Composite Design - Uniform Precision (CCD), a response surface methodology using a software JMP Pro version 13. The results indicated that the optimal extraction conditions were found to be enzyme concentration (78.0 µg/mL), temperature (41oC), time (90 min), and the ratio of material to the enzyme (1:26 g/mL). Under such conditions, the highest content of flavonoids (24.04 ± 0.05 mg/g, dry matter) was obtained and validated. It can be concluded that the flavonoids can be optimally extracted under the optimal extraction conditions with assistance of cellulase.