Effects Of Antioxidants On The Oxidative Stability Of Gardenia Fruit Oil

In this paper,the effects of different storage conditions on the antioxidant stability of refined gardenia fruit oil were studied,and the corresponding oxidation kinetics model was established to predict the shelf life of gardenia fruit oil.Analysis of the effect of different antioxidants on the oxidative stability of gardenia fruit oil,improve the oxidation stability of selected antioxidant effect of gardenia fruit oil well,test compound antioxidants,through the response surface design to find out the optimal proportion of compound,analyzes its influence on the stability of gardenia fruit oil oxidation at frying temperature.The results are as follows:(1)The effects of light,oxygen and temperature on the oxidation stability of refined gardenia fruit oil were studied by Schaal oven acceleration method with peroxide value as index.The experimental results show that: The storage time of gardenia fruit oil was shortened by strong light and aeration,especially by oxygen.The higher the temperature,the faster the oil oxidation.Under different temperature conditions,the peroxide value data accorded with the first-order kinetics equation,combined with the Arrhenius formula,get the prediction model of oxidation kinetics of gardenia fruit oil C =C0 ?e(e(-4495.1/T+11.69)?t).The equation is used to speculate the shelf life of refining gardenia fruit oil under sealed avoid light conditions at 25 ?,20 ? and 15 ? were 95 D,123 D and 160 D respectively.(2)The effects of dl-a-tocopherol,grape seed extract,BHT,TBHQ,tea polyphenol,tea polyphenol palmitate,ascorbic acid palmitate and rosemary extract on the oxidation stability of gardenia fruit oil were studied.The results are as follows: Tea polyphenol palmitate > TBHQ > Tea polyphenol > Rosemary extract > Ascorbic acid palmitate > BHT >Grape seed extract > dl-a-tocopherol.Comparison the optimal concentration of the 5 kinds antioxidants,the results showed that: The optimum concentration of ascorbic acid palmitate was 0.02%,rosemary extract was 0.07%,TBHQ was 0.02%,tea polyphenol was 0.02%,tea polyphenol palmitate was 0.04%.(3)A combination test of tea polyphenols,tea polyphenol palmitate,ascorbyl palmitate,rosemary extract these 4 kinds of natural antioxidants was carried out to obtain antioxidants which are more suitable for gardenia fruit oil.Response Surface Design,in line with the simultaneous use of antioxidants,the sum of their respective dosages in the most ambassadorial dosage should not exceed the "1" requirement the optimum formula was obtained as follows: tea polyphenol 0.01% + tea polyphenol palmitate 0.015% + ascorbic acid palmitate 0.005% + rosemary extract 0.018%.(4)The protective effects of optimized formulation,TBHQ and tea polyphenol palmitate on gardenia fruit oil at high temperature were compared with each other by physical and chemical indexes and fatty acid composition.The results showed that: The optimized formula showed the stability and good antioxidant property of the compound antioxidant.The peroxide value of the optimized formula only 0.211 g/100 g,TBHQ and tea polyphenol palmitate palmitate were 0.255 g/100 g and 0.235 g/100 g respectively after 32 hours of heating,which were higher than the optimized formula.For unsaturated fatty acids,the optimized formula still contains 70.9%,TBHQ 70.24% and tea polyphenol palmitate only 69.71% after 32 hours of heating.