Research On The Antioxidant Efficacies Of Alpha-tocopherol In Camellia Oil

Addition of synthetic antioxidants(BHT,BHA,TBHQ)has been widely used in the oil production industry to slow the oxidation of oils.As the safety hazard of synthetic antioxidants becomes increasingly clear,the use of safe natural antioxidants instead of synthetic antioxidants has become the inevitable development of the edible oil industry.Alpha-tocopherol is an endogenous antioxidant present in edible oil,and is the most important component of vitamin E,exerting nutritional functions such as antioxidant activity in edible oil.In this paper,the antioxidant activity of ?-tocopherol in Camellia oil was studied.First,a GC-MS method for the simultaneous detection of tocopherols and their oxidation product in oil was established.Followed by the addition of ?-tocopherol to Camellia as the research system to explore the physicochemical properties and oxidation stability of Camellia oil under high temperature frying conditions.Finally,the free radical scavenging ability and antioxidant activity of the system were investigated.Through the above research the antioxidative efficacies of alpha-tocopherol in Camellia oil was evaluated comprehensively.The main research results are as follows:(1)A synchronous method for the determination of ?-,?-,?-tocopherol and ?-tocopherol in edible oil.The organic solvent was used to ultrasonic extraction of tocopherol and its oxidation products in tea oil.The extraction conditions were optimized by single factor and orthogonal experiments.Finally,using gas chromatography mass spectrometry simultaneous detection ?-,?-,?-tocopherol and ?-tocopherol quinone in oil.The experimental results show that the best pretreatment conditions are: extraction temperature of 60 ?,solvent volume of 2.5ml,methanol: ethanol ratio of 9: 1.GC-MS detected the peak time within 18 min and the separation effect was obvious.The detection limit was 0.1ug/ml-0.2ug/ml,and the quantitative limit was 0.2ug/ml-0.5ug/ml.In the range of 2ug/ml-200ug/ml,the above four substances had good linearity relationship(r2> 0.999)and the recoveries ranged from 89% to 95%,the spike recovery and relative standard deviation of the results meet the requirements for trace analysis.The results show that this method synchronization detection ?-,?-,?-tocopherol,?-tocopherol quinone in oil is efficient and feasible.(2)Correlation analysis of the physicochemical properties on edible oil with ?-Tocopherol under frying condition.The decrease trend of alpha-tocopherol in rapeseed oil,peanut oil,Camellia oil and corn oil under the frying temperature of 180? was compared.The results showed that corn oil decreased rapidly and Camellia oil decreased slowly.The structure of different vegetable oils was analyzed: the higher the content of unsaturated fatty acids in vegetable oils,the higher the proportion of fatty acids distributed in the Sn-2 position,the better the protective effect on ?-tocopherol.Under the condition of high temperature frying: exogenous alpha-tocopherol has the effect of inhibiting the increase of the yellow value,promoting the increase of the red value,and has the effect of protecting the unsaturated fatty acid in the tea oil.Schaal oven method to accelerate the oxidation of camellia oil test results showed that: the addition of exogenous ?-tocopherol can inhibit the acid value,peroxide value,the carbonyl value rise,while retarding the iodine reduce.(3)Evaluate the effects of ?-tocopherol in vitro and vivo antioxidants and lipid metabolism of camellia oil.By examining the DPPH radical scavenging rate and the total reducing power,we can conclude that addition of the same dosage of artificial antioxidant TBHQ and natural antioxidant ?-tocopherol can improve the antioxidant activity of camellia oil,the antioxidant activity of TBHQ in vitro was stronger and high temperature stability.On the basis of the optimized parameters,groups of mice were orally dosed camellia oil with ?-tocopherol and TBHQ for 7 weeks,the lipid metabolism and related antioxidant activity were evaluated,analysis of body weight,liver index,spleen index,liver fatty acid composition and other physiological indicators.The results showed that the addition of ?-tocopherol and TBHQ to camellia oil can effectively improve the liver fatty acid unsaturation in mice and does not cause damage to the mice body.Determination the levels of serum TC,TG,HDL-C,LDL-C in mice.The results showed that the addition of ?-tocopherol and TBHQ in camellia oil reduced the serum TC,increased the serum TG,increased the serum HDL-C and decreased the LDL-C,effectively preventing hyperlipidemia.The preventive effect of hyperlipidemia is proportional to the dosage of ?-tocopherol.The preventive effect of camellia oil before and after heating in ?-tocopherol group is better than that of TBHQ,but camellia oil in TBHQ group is less affected by high temperature.The indexes of liver anti-oxidative activity were detected: MDA,SOD and GPX.The results of MDA in liver of mice showed that the addition of ?-tocopherol to camellia oil can decrease the MDA content in liver of mice,high temperature process can significantly reduce the effect of ?-tocopherol inhibition of MDA.The addition of TBHQ to camellia oil increased the concentration of MDA in liver of mice,and the effect at high temperature on the inhibition of MDA in TBHQ group was not significant.SOD activity in liver of mice showed that addition of ?-tocopherol to camellia oil enhanced the SOD concentration better than TBHQ,but the lifting effect at high temperature was significantly reduced,high temperature frying can reduce this effect.The result of GPX in liver of mice showed that GPX concentration was increased both before and after high-temperature ?-tocopherol addition in camellia oil,and no effect on GPX concentration before and after TBHQ high temperature treatment.