Study On Preparation Of Xanthoceras Sorbifolia Oil And Protein,and Oxidative Stability Of Oil

Xanthoceras Sorbifolia Bunge is a Chinese new woody oil plant,which contains 55% oil and 28% protein in the kernel.However,more attention has been paid on the ecological value than its edibleness.In this paper,preparation,physicochemical property,active ingredients and oxidative stability of Xanthoceras Sorbifolia oil were studied: simultaneous extraction of xanthoceras sorbifolia oil and protein by aqueous enzymatic method were studied;a comparative research on the properties and oxidative stability of four different extraction methods of xanthoceras sorbifolia oil was designed,in order to determine the proper way to prepare xanthoceras sorbifolia oil;physical-chemical changes in xanthoceras sorbifolia oil during heating at frying temperature for estimating whether xanthoceras sorbifolia oil is considerable to be good frying/cooking oil.The main research results were as follows:(1)The content of nutlet was 46%,the fat content and protein content of which was 58.16% and 29.53%,respectively.Content of oil in the whole seed was 26.75%,which is much higher than other oil crops.Orthogonal experiment was applied to optimize the extraction conditions of xanthoceras sorbifolia oil and protein.Results showed that optimum conditions were the ratio of cellulose and pectinase 1:2,pH 5,temperature 50?,the ratio of solid to liquid 1:5,time 3.0 h and enzyme dosage 1500 u/g.The yield of xanthoceras sorbifolia oil reached 35.5%,and the yield of xanthoceras sorbifolia protein reached 14.56%.A comparison between the protein prepared by Aqueous Enzymatic Method(AEP)and alkali extraction and acid precipitation(AAP)showed that,the microstructure was quite different for the purity of the protein.SDS-PAGE results indicated that Xanthoceras sorbifolia protein showed five main bands,the relative molecular mass of which was 37.9kDa and 25.2kDa.Both of Amino acid composition were similar.(2)Four extraction methods are Soxhlet extraction method(SEM),Screw press method(SPM),Aqueous enzymatic process(AEP),Supercritical carbon dioxide extraction(SF-CO2).The color of SEM was lightest,water and volatile matter of AEP with 1.81 was highest,the acid value in SPM oil was the lowest,and the peroxide value in AEP was lowest.The main unsaturated in xanthoceras sorbifolia oil was linoleic acid,than followed oleic,and the content of nervonic was 2.73% at least.The total saturated acid and total monounsaturated acid was highest in AEP.The total polyunsaturated acid was highest in SEM.And the tocopherols,sterols content was highest in SEM.During the 62? storage,acid value didn't change much,but the peroxide value showed exponent,by the way the total tocopherols content reduced.The higher concentration of the sample was,the higher of DPPH radicals scavenging ratio was.In generally speaking,considering the quality of xanthoceras sorbifolia oil,AEP was suggested,than refine.(3)Due to the different duration storage at heating temperature,the langer the duration was,the lighter the color was.And the acid value and the peroxide value showed upward trend,so as carbonyl value and TBARS value.And the DPPH radicals scavenging ratio decreased,so as the aging time.For the analyze of content of fat acid,the total saturated acid increased,the monounsaturated acid and polyunsaturated acid both showed downward trend.The total tocopherols content reduced,especially for ?-tocopherol.