Research On The Multi-component Integrated Detection Method Of Fat Accompaniments In Three Woody Plant Oil

Edible vegetable oils provide essential energy and fatty acids for human life activities and organismal metabolism.In addition,vegetable oils contain 2%-5% of secondary metabolites,also called fat concomitants,including vitamin E,polyphenols,squalene,phytosterols and other fat-related substances,and these compounds exhibit important health-promoting effects.The fat concomitants of different types of vegetable oils show large differences in type and content,which determine the specific nutritional value and health functions of different types of vegetable oils.Therefore,analyzing the composition and content of fat concomitants in oils is important for conducting quality research on edible vegetable oils and developing and standardizing industry standards.As the most important wood-based oils,camellia seed oil,olive oil and walnut oil have solved the problem of insufficient supply of edible oil in China to a certain extent.There are few studies on the detection and analysis methods of multi-component integration of fat concomitant in woody oil.In this paper,GC-MS and LC-PDA were used to establish a multi-component integrated detection method for fat concomitant in three woody oils,and the established methods were used to qualitatively and quantitatively analyze 10 common vegetable oil fat concomitants.1.A high-sensitivity synchronous detection technology of GC-MS for 14 trace functional nutrients,including squalene,vitamin E,and phytosterols has been established.The fat concomitants in vegetable oil were extracted by the method of solid phase extraction combined with saponification,and the form of sterol can be separated while protecting vitamin E.On the basis of single-factor experiments,a central combinatorial design was used to optimize the extraction condition of squalene,campesterol,brassicasterol,stigmasterol,β-sitosterol,lanosterol,β-amyrin,lupeol,cycloartenol and 24-methylene cycloartenol.The optimal extraction conditions are:saponification temperature 70 ℃,saponification time 40 min,concentration of saponification solution is 2mol/L.The limit of detections were range from 0.01 μg/m L to 0.05 μg/m L,the limit of quantifications were 0.033 μg/m L～0.167 μg/m L,and the recovery rates of the sample spiked were between 91.29% and 111.93%,the relative standard deviation of the inter-day and intra-day precision were 4.83%～6.11%.Validation experiments showed that the method can further separate different forms of sterols while protecting vitamin E,with high sensitivity and good stability,which was suitable for simultaneous quantitative analysis the three types of functional nutrients in vegetable oils.2.The HPLC-PDA simultaneous detection technology of 20 kinds of polyphenols was established.This method covers 20 polyphenolic compounds that are abundant in three kinds of wood oils,including gallic acid,gallocatechin,hydroxytyrosol,tyrosol,catechin,chlorogenic acid,vanillic acid,ferulic acid,Epicatechin,epicatechin gallate,phydroxycinnamic acid,luteolin,benzoic acid,ellagic acid,oleuropein,cinnamic acid,quercetin,naringenin,kaempferol,apigenin.The limit of detection was 0.01-0.08μg/m L,and the limit of quantification was 0.033 μg/m L～0.266 μg/m L.The pretreatment and extraction conditions of polyphenols were as follows: ultrasonic temperature 60 ℃,ultrasonic time 90 min,ultrasonic power 100%.The established simultaneous quantitative analysis and detection method of 20 polyphenol compounds is suitable for the analysis of edible vegetable oil.3.The types and contents of 3 kinds of woody oils and 10 kinds of main edible vegetable oils were analyzed by the method established in this study.Vegetable oil samples are: 3 types of extra virgin olive oils,3 types of camellia seed oils,walnut oil,2kinds of sunflower oil,2 types of flaxseed oils,flax oil,2 kinds of rice oils,safflower oil,2 types of sesame oil,small ground sesame oil,3 types of tertiary rapeseed oil,secondary rapeseed oil and 2 types of soybean oil,total of 24 samples.The results showed that there were significant differences in the content and types of fat concomitants in the tested vegetable oils.The content of squalene in olive oil was the highest and the lowest in sesame oil,Sesame oil has the highest total phenolic content,and camellia oil has the lowest content.Sunflower oil has the highest total tocopherol content,most vegetable oils are mainly in the form of alpha-tocopherol,while flaxseed oil,flax oil,soybean oil,sesame oil,and sesame oil,tertiary rapeseed oil and secondary rapeseed oil is mainly in the form of γ-tocopherol.Except Camellia oleifera seed oil,the common phytosterols in other vegetable oils are campesterol,stigmasterol and β-sitosterol.Rapeseed oil,rice bran oil,and sunflower oil mainly exist in the form of bound state(>50%),of which the bound sterol in rice bran oil reaches10256.15 mg/kg,while olive oil,linseed oil,flax oil,safflower seed oil,sesame oil and sesame oil exist in the form of free state(>50%),and the proportion of free and bound states in soybean oil and walnut oil is equal.