Antioxidant effects of citrus pomace extracts processed by super-heated steam. (April 2018)

• Record Type: Journal Article
• Authors: Wang, Lei; Jo, Min-Ji; Katagiri, Riho; Harata, Kaori; Ohta, Moemi; Ogawa, Ayane; Kamegai, Masayuki; Ishida, Yasuyuki; Tanoue, Shota; Kimura, Sojiro; Lee, Seung-Cheol; Jeon, You-Jin
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 90(2018)
• Page Start: 331
• Page End: 338
• Publication Date: 2018-04
• Subjects: Citrus pomace -- Super-heated steam -- Phenolic content -- Flavonoid content -- Antioxidant activity; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2017.12.024
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: This study was performed to investigate the enhanced antioxidant effects of citrus pomace (CP) extracts processed by super-heated steam (SHS). CP extracts were obtained using a closed SHS system at three different temperatures (100, 200, and 300 °C) with an extraction time of 10 or 20 min. These extracts were evaluated for their antioxidant activities by measuring their DPPH, alkyl, and hydroxyl radical scavenging activity using Electron Spin Resonance (ESR) spectroscopy and for their protective effects against H2 O2 -induced oxidative stress in Vero cells. All extracts exhibited strong radical scavenging activities and protective effects against H2 O2 -induced Vero cell damage. Especially, the SHS-CP extracts obtained at 300 °C with extraction times of both 10 min and 20 min exhibited antioxidant activities that were significantly higher than those of ethanol extracts and SHS-CP extracts obtained at other temperatures. The total phenolic and flavonoid contents of SHS-CP extracts and their antioxidant activities were found to be increased with elevated processing temperatures. Moreover, gas chromatography/mass spectrometry (GC/MS) in the presence of a methylating reagent revealed that some characteristic polyphenols and polyhydroxycyclohexanes were present in the SHS-CP extracts. Thus, this study demonstrated that SHS extraction is an efficient and environmentally friendly method for extracting antioxidants from CP. Graphical abstract: Highlights: The antioxidants of citrus pomace (CP) were enriched by super-heated steam (SHS) processing. Antioxidant activities of SHS extracts had been evaluated. The optimum SHS extraction condition of CP had been confirmed. The major compounds of CP extracts had identified by gas chromatography/mass spectrometry.