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Antioxidant and Antimutagenic Properties and Polysaccharide Composition Analysis of Lyciuum chinense
|關鍵字:||Lycium chinense;枸杞;antioxidant properties;antimutagenic properties;polysaccharide;structural analysis;抗氧化性質;抗致突變性質;多醣;結構分析||出版社:||食品科學系||摘要:||
The objectives of this research were to study the antioxidant, antimutagenic properties of methanolic and water extracts from L. chinense Mill. , the monosaccharide constituents, and structural analysis of polysaccharides. Their structures were elucidated by spectroscopic analysis and comparison with known compounds. Fruit of L. chinense contained 26.94% of moisture. In dry matter, fibers and carbohydrates were major components, and crude protein (13.15%).
Methanolic extracts from L. chinense showed very high antioxidant properties. Antioxidant activity using conjugated diene method, the reducing power, the scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH) and the chelating effect on ferrous ions of methanolic and water extracts from L. chinense increased with the increased concentration, but water extracts was not as good as expected. Naturally occurring antioxidant compounds, including ascorbic acid, b-carotene, tocopherols, and total phenols were found in methanolic extracts from L. chinense. However b-carotene and tocopherols were not found in water extracts. Total antioxidant components were 6.29, 4.04, 6.58 and 7.57 mg/g for methanolic, cold water, boiling water, heating water to boiling extracts, respectively.
The concentration of water extracts from L. chinense used in this study was neither toxicity nor mutagenic to the Salmonella typhimurium TA97, TA98, TA100 and TA102. Methanolic extracts of L. chinense contained antimutagens capable of inhibiting the mutagenicity of direct-acting such as MNNG, NQNO the indirect-acting mutagen, B[a]P.
The total sugar contents of boiling alkaline extracts from L. chinense were higher than boiling water extracts. The compositions of neutral monosaccharide in boiling water extracts were ribose, mannose and glucose. Glucose was the major monosaccharide in boiling water and alkaline extracts of polysaccharides from L. chinense. Polysaccharides of L. chinense were separated using gel filtration, and showed a molecular of about 104 Da. X-ray, DSC and NMR elucidated their structure. In DSC and 1H, 13C-NMR spectral comparism showed the polysaccharides crystal of boiling alkaline extracts were more tight and regulation. The DSC and NMR spectrum showed functional group of sugar from water extracts of heating to boiling for 2 hours polysaccharides was lowest, but the absorbance peak markedly. The exothermic behaviors of water extracts of heating to boiling for 2 hours polysaccharides were examined by DSC, so supposition it impure. It could be study their physiological activities, advance analysis. For the application in healthy food, further research on the mechanism of polysaccharide properties is in progress.
Considering these studies, the major components in L. chinense were carbohydrates and fibers; methanolic extracts from L. chinense in the antioxidant activity better than water extracts. No toxicity or mutagenicity in S. typhimurium TA97, TA98, TA100 and TA 102. Both boiling water and alkaline extracts contain small molecular polysaccharide, and similar monosaccharide components.
Keyword: Lycium chinense, antioxidant properties, antimutagenic properties, polysaccharides, structural analysis
|Appears in Collections:||食品暨應用生物科技學系|
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