| China has a large acreage of camellia planting, and high yield of camellia oil. Oil-tea camellia is the residue left in the process of the camellia oil production, which contains many active substances such as polyphenols, tea saponin, tea seed polysaccharide and protein, etc. The reasonable utilization of oil-tea cake has been widely concern. In order to improve the comprehensive utilization of oil-tea camellia resources, this paper design the optimization extraction experiments of antioxidant active substances on oil-tea camellia meal, analyses and evaluate the antioxidant activity of oil-tea camellia meal testing, and use oil-tea camellia meal to improve the oil oxidation stability, finally analyzed the kind and content of polyphenols in oil-tea cake. The main research contents and results are as follows:(1) Using three methods as hot reflux extraction and ultrasonic extraction, soxhlet extraction, and four kinds of solvent as distilled water, ethanol, methanol, acetone solvent to extract antioxidant activity material in oil-tea cake. Judgment based on total phenol content extraction effect, choose the hot ethanol reflux method to extract oil-tea cake is optimized. In four factors,as solvent concentration, extraction temperature, extraction time, extraction ratio of material to liquid, by single factor experiments of camellia cake, and by through the L16 (44) orthogonal experiment of four factors and four levels,the optimum extraction condition is:extraction time is 3 hours,60% ethanol concentration, extraction temperature is 80 ℃, and extract the ratio of material liquid 1:20. The optimal extract the total phenol content was 1437.21±26.18 mg/100g,DW.(2) Text the ORAC from the samples of select extraction method and samples of single factor extract experiments, The highest ORAC value up to 370.62±38.25 μmol TE/g,DW, which is the acetone ultrasonic extraction of crude extractings from oil-tea cake. The ORAC value of Samples has positive correlation with polyphenol content. In different conditions of ethanol heat reflux extraction samples, the optimal conditions to extract the sample S10 of the highest ORAC value,290.31±6.49 μmol TE/g,DW. The evaluation of extract oil-tea cake antioxidant activity result is:The equivalent concentration of UES2, SES9 and RES 19 is higher than gallic acid, other samples are similar with gallic acid.(3) Using HPLC method test and analysis the kind and content of oil-tea cake polyphenols. Test results are as follows:Oil-tea cake contains catechin and epicatechin, rutin and quercetin, and there are other polyphenols did not check out. Hot reflux acetone extraction method is the best way to extract the various components, and different extraction method and solvent on the extraction effect of each composition was different.(4) Using Rancimat method to evaluate oil-tea cake as antioxidants to the stability of tea oil application, the results showed that extract oil-tea cake for tea oil has antioxidant activity, longest induction time was 7.82± 0.10 hours, induction of extension rate was 297.46 ± 6.75%.In adding a single antioxidant experiment, on lower concentration is higher than the antioxidant effect of gallic acid, On high concentration, oil-tea cake extract antioxidant effect was less than a gallic acid antioxidant effect.In adding different proportion of compound extract oil-tea cake and gallic acid experiment, the antioxidant effect of oil-tea cake and gallic acid is negative synergy. The best result in Distribution effect experiment is:added gallic acid content is 150 mg/kg and extract oil-tea cake content is 50 mg/kg, induction time 7.39±0.31 h, induction time extension rate was 275.59 ± 10.24%. |
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