Ultrasound-Assisted Extraction of Antioxidants in Misai Kucing (Orthosiphon stamineus)

Molecules

Swee Kheng Ho²  Chin Ping Tan²  Yin Yin Thoo³  Faridah Abas¹ 

[1] Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, UPM 43400, Serdang, Selangor, Malaysia; E-Mail:;Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, UPM 43400, Serdang, Selangor, Malaysia; E-Mail:;School of Science, Monash University Malaysia, Bandar Sunway, Petaling Jaya 46150, Selangor, Malaysia; E-Mail:

关键词: ultrasound;    extraction;    antioxidants;    Misai Kucing;    Orthosiphon stamineus;   

DOI  :  10.3390/molecules190812640

来源: mdpi

【 摘 要 】

Ultrasound-assisted extraction (UAE) with ethanol was used to extract the compounds responsible for the antioxidant activities of Misai Kucing (Orthosiphon stamineus). Response surface methodology (RSM) was used to optimize four independent variables: ethanol concentration (%), amplitude (%), duty cycle (W/s) and extraction time (min). Antioxidant compounds were determined by total phenolic content and total flavonoid content to be 1.4 g gallic acid equivalent/100 g DW and 45 g catechin equivalent/100 g DW, respectively. Antioxidant activities were evaluated using the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+) radical scavenging capacity assay and the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging capacity assay to be 1,961.3 and 2,423.3 µmol Trolox Equivalent Antioxidant Capacity (TEAC)/100 g DW, respectively. Based on the optimal conditions, experimental values were reported to be close to the predicted value by RSM modeling (p > 0.05), indicating the suitability of UAE for extracting the antioxidants of Misai Kucing. Rosmarinic acid, kaempferol-rutinoside and sinesetine were identified by high performance liquid chromatography-mass spectrometry.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.