Subcritical Water Extraction of Antioxidants from Curculigo latifolia Root

Abstract

This study aims to extract antioxidant compounds from Curculigo latifolia root by subcritical water extraction (SWE). The influence of extraction temperature and time on the antioxidant activity of C. latifolia root extract was investigated in terms of extraction yield, total phenolic content (TPC), total flavonoid content (TFC), 2, 2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The highest extraction yield (36.5%), TPC (92.55 mg GAE/g), TFC (13.26 mg RE/g), and antioxidant activities by ABTS (66.8 mg trolox equivalent/g sample) and DPPH (128.7 mg trolox equivalent/g sample) were detected at 180°C and 30 minutes extraction time. Based on the results, the optimum condition was selected at 180°C and 30 minutes of extraction. The sample was screened by using liquid chromatography-mass spectrometry (LC-MS) analysis where the phenolic compounds detected were structured based on their [M-H]-peak. The detected phenolic compounds were monobenzone, hydroquinone, phloridzin, pomiferin, mundulone, scandenin, and dimethyl caffeic acid. According to these findings, SWE is a promising, environmentally friendly, and efficient technology in the exploitation of natural products for the development of food and nutraceutical commodities.