Effect Of Roasting On Antioxidant Components Of Camellia Oleifera Seed Oil And Its Mechanism

With the growing of the population and economic development,the demand for high-quality vegetable oil has increased significantly due to its important role in health protection and prophylactic function.Camellia seed oil(CSO)has a high content of unsaturated fatty acids,and is rich in functional active substances,which has certain health care effects on human health.At the same time,many studies have proved that the human body can effectively strengthen its own antioxidant system ability by oral intake of natural antioxidant substances.Therefore,a simple pretreatment process was used to find natural antioxidant active substances.CSO,as a kind of high quality edible oil for both diet and therapy,is rich in many active substances with antioxidant ability.Because of traditional detection method have some drawbacks,may lead the sample determination results is not accurate.Therefore,the establishment of a fast and convenient online antioxidant activity determination method will be conducive to a better and efficient evaluation of the antioxidant capacity of food.In the first part,the effects of different roasting techniques on physicochemical parameters and active components of CSO were studied.The effects of roasted seed temperature and time on the oleic acid value,peroxide value,fatty acid composition and active components of Camellia oleifera seed were systematically analyzed.Analysis found that the roasted seeds before processing of tea seed oil has a good quality:the acid value and peroxide value showed a trend of decline and are within the scope of the standard provisions of the state,fatty acid composition and content,not affected by the significance of trace lipid companions(polyphenols,tocopherol,squalene)with the roast temperature increasing and the time prolonging.In the second part carry out to study the effect of different strength roasting on off-line antioxidant assay index(DPPH radical scavenging ability,ABTS radical scavenging ability,total antioxidant ability,absorptive ability of oxygen free radicals)and oil oxidative stability of CSO.Results show that with the increase of roasting temperature and the extension of time,the antioxidant capacity of camellia seed oil,and oxidation induction time were significantly improved(p<0.05)Correlation analysis of the polyphenols content and antioxidant capacity measured in the first part showed that the total phenol content of CSO was significantly correlated with DPPH(r=0.970)ABTS(r=0.980)FRAP(r=0.990)ORAC(r=0.922).In the third part,in order to comprehensive evaluate the effect of different roasting conditions of CSO oxidation resistance and find the key compound of antioxidant ability,according to principal component analysis(PCA)choose FRAP as post column reaction reagent to realize the separation of the sample and rapid determination of antioxidant activity of individual compounds concurrently.By online HPLC-FRAP method,establishing and optimizing the antioxidant capacity detection system,the optimum online HPLC-FRAP method conditions were as follows:(1)HPLC analysis system:chromatographic column is Shimadzu-C18(4.6 mm 250 mm,5 μm);Mobile phase:Solvent A is 0.2%formic acid aqueous solution(Vformic acid:Vwater=2:998),Solvent B is 100%methanol;Gradient elution procedure was adopted.Flow rate:1 mL/min;Column temperature:30℃;The injection volume:20 μl.detection wavelength:280 nm(2)Post-column analysis system:FRAP(mixed with 1 mmol/L FeCl3,5 mmol/L TPTZ and 0.1 M Acetic acid buffer)was introduced at the flow rate of 1 mL/min,the detection wavelength was set at 593 nm and the reaction temperature was 70℃.