title: Microwave-assisted extraction of polyphenols from Camellia oleifera fruit hull.
abstract: The abundant fruit hulls of tea-oil tree (Camellia oleifera) are still underutilized and wastefully discaded to pollute the environment. In order to solve this problem and better utilize the fruit hulls of C. oleifera, a microwave-assisted extraction system was used to extract their polyphenols using water as the extraction solvent. A central composite design (CCD) was used to monitor the effects of three extraction processing parameters--liquid:solid ratio (mL/g), extraction time (min) and extraction temperature (°C)--on the polyphenol yield (%). The results showed that the optimal conditions were liquid:solid ratio of 15.33:1 (mL/g), extraction time of 35 min and extraction temperature of 76 °C. Validation tests indicated that under the optimized conditions the actual yield of polyphenols was 15.05 ± 0.04% with RSD = 0.21% (n = 5), which was in good agreement with the predicted yield. Phenolic compounds in the extracts were analysed by HPLC, and gallic acid was found to be the predominant constituent. The total flavonoid content in the extracts was determined and high total flavonoid content was revealed (140.06 mg/g dry material).
authors.affiliation: Institute of Chemical Industry of Forest Products, CAF, Jiangsu Province, Nanjing 210042, China. zhll20086@gmail.com
authors.forename: Liangliang
authors.initials: L
authors.lastname: Zhang
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Wang
authors.forename: Dongmei
authors.initials: D
authors.lastname: Wu
authors.forename: Man
authors.initials: M
authors.lastname: Xu
authors.forename: Jiahong
authors.initials: J
authors.lastname: Chen
mesh_terms: D028244:Camellia / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification*; D005638:Fruit / Q000737:chemistry*; D008872:Microwaves; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification*; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification*; D059808:Polyphenols; D015203:Reproducibility of Results
chemical_list: D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols