Mechanism Of Resveratrol Inhibiting The Formation Of Thermally Induced Trans Fatty Acids In Peanut Oil

Peanut oil is the fourth largest edible oil in China,its consumption is increasing year by year,reaching 3.129 million tons in 2019.Cis unsaturated fatty acids in peanut oil are easy to isomerize into trans fatty acids that are harmful to human body during processing and storage.In 2018,the World Health Organization(WHO)released a "replacement" plan to completely eliminate artificial trans fats that exist in the global food supply chain by 2023.Thus,the resveratrol peanut oil was prepared by physically dissolving resveratrol in peanut oil to explore the effect of resveratrol on thermally induced trans fatty acids in peanut oil,and further reveal the mechanism of resveratrol on the formation of trans fatty acids,providing a theoretical basis for the precise control of trans fatty acids,the main conclusions are as follows:(1)Preparation and process optimization of resveratrol peanut oil.Using the physical solubilization method,the optimal values of resveratrol addition(200 mg/kg),water bath shaking time(1 h),water bath shaking temperature(40?),magnetic stirring time(4 h),and magnetic stirring temperature(50?)on the solubilization rate were determined by a single factor test.The response surface optimization was carried out on the three main factors that have a greater influence on the solubilization rate,and the optimal conditions were obtained: the resveratrol addition was 183.00 mg/kg,the water bath vibration temperature was 38.83? and the magnetic stirring time was3.50 h.The solubilization rate of resveratrol peanut oil reached(95.91±0.24)%,and the resveratrol content in the prepared resveratrol peanut oil was 175.51±0.44 mg/kg.(2)Quality evaluation of resveratrol peanut oil.The microstructure,composition and basic physical and chemical indexes of prepared resveratrol peanut oil were analyzed.The results showed that the resveratrol peanut oil was uniform and stable without precipitation;the composition of triglycerides remained unchanged,and the contents of major triglycerides such as OOL,OOO and OLL increased(accounting for more than 75%).The types of fatty acids remained unchanged,while the content of fatty acids decreased,especially for the C18:2-9c,12t(13.11%)and C18:2-9t,12c(4.92%).The color of resveratrol peanut oil was light yellow,and the acid value and peroxide value were low.The shelf life of resveratrol peanut oil was two times longer than that of peanut oil.(3)Effect of resveratrol on the formation of trans fatty acids in peanut oil was studied.A high-throughput and sensitive fatty acid method was established.On this basis,it was found that resveratrol can inhibit the formation of trans fatty acids in peanut oil under the conditions of 120-160?.The inhibition rate of resveratrol on the total trans fatty acids,C18:1-9t,C18:2-9c,12 t and C18:2-9t,12 c were 10-30%,38-64%,13-18% and 6-19%,respectively.The reason why resveratrol inhibited the formation of trans fatty acid was increased the formation energy barriers of the total trans fatty acid(5.91%),C18:1-9t(5.82%),C18:2-9c,12t(15.45%)and C18:2-9t,12c(8.05%),which made the formation of trans fatty acids more difficult.The control kinetic models of the total trans fatty acid,trans-oleic acid and trans-linoleic acid were established.(4)Mechanism of resveratrol on the formation of trans fatty acid in peanut oil was revealed.It is clear that the molecular activity of trans-resveratrol is greater than that of cis-resveratrol by quantum chemical calculation,and its hydroxyl 4' site activity is the highest.On this basis,the structure optimization and chemical reaction calculation of trans-resveratrol and main triglyceride OOL molecules of peanut oil were carried out,the free radical mechanism and proton transfer mechanism of resveratrol on the inhibition of trans fatty acid in peanut oil were revealed,and the speed control steps,key structures and action sites of resveratrol on the inhibition of trans-oleic acid and trans-linoleic acid were determined.