The effect of blanching and extraction method on total phenolic content, total flavonoid content and antioxidant activity of Kencur (Kaempferia galanga. L) extract

Kencur (Kaempferia galanga. L) is a rhizome used to make Jamu, a traditional herbal drink commonly consume in Indonesia, that has been studied to be rich in phytochemical sources with biological properties that contribute to the health of the human body. The purpose of this study is to evaluate the effect of blanching treatment and extraction methods (maceration and ultrasonic) on total phenolic, total flavonoid, and antioxidant activity of kencur extract. The kencur samples were divided into five treatments; control (without any treatment), fresh by maceration extraction, blanching by maceration extraction, fresh by ultrasonic extraction, and blanching by ultrasonic extraction then analyzed the pH value, total phenolic, total flavonoid, and antioxidant activities using the 2-2-diphenyl-1 method-picrylhydrazyl (DPPH). The results of this study indicate that the kencur extract sample has a pH value ranging from 6.2 to 6.5. The total phenolic sample of kencur extract by blanching and ultrasonic extraction (67.32 mgGAE/L) was higher than control (41.66 mgGAE/L). Total flavonoid sample of kencur extract by blanching and ultrasonic extraction (452.76 mgEK/L) was higher than control (282.87 mgEK/L). The antioxidant activity sample of kencur extract by blanching and ultrasonic extraction (56.20 RSA) was higher than control (22.1 RSA). This study concludes that the combination of blanching treatment with ultrasonic extraction showed a significant increase in total phenolic, total flavonoid, and antioxidant activity of kencur extract. © Published under licence by IOP Publishing Ltd.