title: Volatile and Nonvolatile Constituents and Antioxidant Capacity of Oleoresins in Three Taiwan Citrus Varieties as Determined by Supercritical Fluid Extraction.
abstract: As local varieties of citrus fruit in Taiwan, Ponkan (Citrus reticulataBlanco), Tankan (C. tankanHayata), and Murcott (C. reticulate×C. sinensis) face substantial competition on the market. In this study, we used carbon dioxide supercritical technology to extract oleoresin from the peels of the three citrus varieties, adding alcohol as a solvent assistant to enhance the extraction rate. The supercritical fluid extraction was fractionated with lower terpene compounds in order to improve the oxygenated amounts of the volatile resins. The contents of oleoresin from the three varieties of citrus peels were then analyzed with GC/MS in order to identify 33 volatile compounds. In addition, the analysis results indicated that the non-volatile oleoresin extracted from the samples contains polymethoxyflavones (86.2~259.5 mg/g), limonoids (111.7~406.2 mg/g), and phytosterols (686.1~1316.4 μg/g). The DPPH (1,1-Diphenyl-2-picrylhydrazyl), ABTS [2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] scavenging and inhibition of lipid oxidation, which test the oleoresin from the three kinds of citrus, exhibited significant antioxidant capacity. The component polymethoxyflavones contributed the greatest share of the overall antioxidant capacity, while the limonoid and phytosterol components effectively coordinated with its effects.
authors.affiliation: Department of Food Science, National Pingtung University of Science & Technology, Pingtung 90090, Taiwan. e933623366@yahoo.com.tw.
authors.forename: Min-Hung
authors.initials: MH
authors.lastname: Chen
authors.affiliation: Department of Food Science, National Pingtung University of Science & Technology, Pingtung 90090, Taiwan. tchuang@mail.npust.edu.tw.
authors.forename: Tzou-Chi
authors.initials: TC
authors.lastname: Huang
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000737:chemistry; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D025924:Chromatography, Supercritical Fluid; D002957:Citrus / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D010936:Plant Extracts / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D013624:Taiwan; D055549:Volatile Organic Compounds / Q000032:analysis
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D055549:Volatile Organic Compounds; C018620:oleoresins
keywords: antioxidant capacity; oleoresin; supercritical fluid extraction; volatile compounds