| In order to utilize Camellia oleifera Abel shell comprehensively,the main chemical components of Camellia oleifera Abel shell was determined by standard methods of China.Lignin and cellulose were separated and charactered by FTIR and 1H-NMR.The Folin-Ciocaileu method was established to determine content of total polyphenols(TP).TP extraction processes were optimized by orthogonal experiment and response surface method.Antioxidant activities of extract from Camellia oleifera Abel shell was evaluated by removal of hydroxyl free radicals,DPPH free radicals,superoxide anion free radical method.The main conclusions are as follows:(1)The main chemical compositions content of Camellia Abel contents Camellia oleifera Abel shell were:12.02 ± 0.01%moisture,17.65±0.04%ash,2.57 ±0.02%alcohol benzyl extract,32.89± 0.31%holo-cellulose,17.69±0.23%cellulose,45.87±0.11%(acid insoluble content of 43.66± 0.34%and acid soluble lignin content of 2.21±0.03%).C=O,-OH,-OCH3 existed in milled wood lignin(MWL)and cellulose enzymatic lignin(CEL),MWL and CEL both belong to the GS type structure.Their structure units were connected to each other by ?-?,?-O-4,?-1,?-5.(2)Gallic acid was used as constrast sample,Folin-Ciocaileu method was suitable for quantitative determination to TP:Folin-Ciocaileu 0.8 mL,10%Na2CO3 6.0 mL,react for 2.0 h at 40?,then determined the absorbance at the wavelength of 760 nm.(3)Ultrasonic-assisted and microwave-assisted extraction methods were superior to the traditional solvent reflux method.The optimal extraction technique of solvent reflux method was as follows:50%ethanol solution as extraction solvent,and liquid volume to material ratio was 20,extracted for 80 min at 70?,and the quality of the exacted TP was 47.08±1.46 mg·g-1.The optimal extraction technique of ultrasonic-assisted method were as follows:61.36%ethanol solution as extraction solvent,liquid volume to material ratio was 13.70,the ultrasonic power of 653.04 w,extracted for 45.77 min at 65.21?,the maximum theory extracting quality of TP was 50.36 mg·g-1,and the actual value was 52.78 ± 1.05 mg·g-1,the relative error was 3.56%.The optimal extraction technique of microwave-assisted methods were as follows:36.24%ethanol solution,liquid volume to material ratio was 10,microwave power of 638.65 w,extracted for 77.86 s,the maximum theory extracting quality of TP was 47.90 mg·g-1,the actual value was 48.78±1.65 mg·g-1,the relative error was 1.8%.(4)Ascorbate acid(Vc)and propylgallate(PG)were used as the contrast samples,determining the antioxidant activity of microwave extraction(ME),ethyl acetate extract by microwave(MS),ultrasonic extraction(UE)and ethyl acetate extract by ultrasonic(US).The results showed they have strong oxidation resistance.Their removing ·OH ability was ranked in an order of MS>PG>UE>ME>US>Vc,and the ability of removing DPPH-free radical was ranked in an order of PG>ME>US>MS>UE>Vc.Moreover,the antioxidant activity of extracts was correlated with TP content.Pyrogallol oxidation was not suitable for evaluating antioxidant activities of TP from Camellia oleifera Abel shell. |
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