The Oxidative Stability Of Pecan Oil And Its Regulation On Lipid Metabolism In Mice

Pecan oil is prone to oxidative deterioration due to rich unsaturated fatty acids profile.In response to the actual demand for production,we have investigaed the fresh cold-pressed extract of pecan oil as raw materials for studying various physical and chemical properties and components of pecan oil,pecan oil microencapsulation optimization process,compared different antioxidants on the stability of pecan oil and microencapsulated pecan oil.We have also explored the effect of pecan oil on lipid metabolism in mice fed high fat diet.This paper aims to establish a basis for the development of pecans based functional food.Pecon oil is mainly composed of palmitic acid,stearic acid,oleic acid,linoleic acid and linolenic acid,with the highest content of oleic acid,accounting for 66% and the ratio of linoleic acid is 26.152%.The optimal preparation conditions for the microcapsules of pecan oil were as follows: solid content 20%,wall-core ratio 6: 1,lecithin 1.0%,soy protein / maltodextrin 3.7: 6.3,at the rate of 72.89%.Furthermore,the antioxidant activity of pecan oil and microencapsulated pecan oil were further explored.After 30 days of accelerated oxidation,the peroxide value of the blank control group reached to120.53 meq/Kg;while,the embedding rate was 72.35%.The peroxide value of the oil was only 42.63 meq/Kg.For addition of 11 different antioxidants,flavonoids(catechins,quercetin,rutin,sesamol)and polyhydroxy cinnamic acid(erucic acid,ferulic acid,caffeic acid,tannin(TBHQ,BHT and BHA)were synthesized and the oil samples were cultured at 60?.The peroxide,anisidine,conjugated diene and thiobarbitone acid reactant(TBARS)values for the test indicators were used for screening out the best antioxidants.By measuring antioxidant DPPH radical scavenging rate and reducing power,the results showed that tannic acid showed the highest DPPH scavenging activity and provided the maximum reducing power.The results of the four indexes showed that the oxidation of the oil samples with the addition of synthetic antioxidants was significantly and steadily improved;while,the addition of polyhydroxy cinnamic acid and flavonoid oil samples showed great differences in different indexes.Caffeic acid could effectively inhibit the oxidation of pecan oil,sesamol and catechins showed slightly improved oxidation stability,and ferulic acid,sinapic acid and rutin no effect.Compared with synthetic antioxidants(TBHQ,BHT,BHA),the antioxidant effect of caffeic acid was observed to be stronger than that of BHT and BHA,and close to that of TBHQ.Taken together,the results of the descending order of the antioxidant effects of different antioxidants on the antioxidant activity of pecan oil were: TBHQ> caffeic acid> BHA = BHT = sesaminol> catechin> quercetin> rutin> tannin = Ferulic acid = sinapic acid.The levels of TC,TG,LDL-C,HDL-C and TC,TG in the serum of the C57 BL / 6J mice were determined.Compared with the high-fat group,consumption of pecan oil TC was decreased by 28%,TG decreased by 15%,HDL increased by 46%,LDL decreased by 44%,plasma leptin increased by 27% and insulin decreased by 20%,adiponectin increased by 73%,GSH increased by 62%,SOD increased by 9%,MDA decreased by 42%.The results showed that the consumption of pecan oil to a certain extent could improve the antioxidant metabolism in mice,and could reduce the generation of lipid peroxidation of the final product to avoid the rise in blood lipids in mice.