Abstract:

Cellulose-assisted extraction was applied to the extraction of flavanoids from peony leaves. Effects of enzyme
dosage, pH, temperature and hydrolysis time on the extraction efficiency of flavanoids were investigated. The optimal
hydrolysis conditions obtained by orthogonal array experiments for the extraction of flavonoids were as follows: enzyme
dosage, 12.5 U/mL; initial pH, 4.5; temperature, 45 ℃; and hydrolysis time, 4 h. Under these conditions, the extraction yield
of flavanoids was 2.43%. Flavanoids from peony leaves were able to scavenge nitrite. The optimal reaction conditions for
nitrite scavenging by the flavanoids were found to be 20 min reaction at 70 ℃ and pH 4.0 after addition of 25 mL (10 μg
sodium nitrate) of the radical scavenger, resulting in a scavenging rate of 62.15%.

Key words: peony leaves, flavanoids, cellulase, nitrite, scavenging