Determination And Evaluation On Benzopyrenes Contaminant In Flaxseed Oil By ELISA And HPLC

Flaxseed oil rich in poly unsaturated fatty acids that dominated by ?-linolenic acid,vulnerable to oxidation,and very easily to produce toxic or carcinogenic polycyclic aromatic hydrocarbons(PAHs)such as benzopyrenes during hotpress extracting processes.There are lacking systematic survey and reported data on the amount and range of Benzopyrene contamination in flaxseed oil in China.High-performance liquid chromatography(HPLC)and gas chromatography-mass spectrometry(GC-MS)detection of benzopyrene are extremely costly and inefficient.Enzyme-linked immunosorbent assay(ELISA)is a relatively simple and inexpensive method,however nowadays ELISA kits determines benzopyrenes rather than benzo(a)pyrene,and its accuracy needs to be evaluated with International method.A total of 154 flaxseed oil samples were collected from supermarkets,open farm product markets and online shops,covering all brands and major geographical origin.Benzopyrenes of all 154 flaxseed oil samples were detected by a ELISA method,and benzo(a)pyrene of 46 samples were determined by HPLC as well.The benzopyrenes and benzo(a)pyrene results of ELISA and HPLC parallel determination on 39 samples were 22.32±15.04 and 5.63±4.69(X ±1SD,?g/L,Kg)respectively,the difference was 4 times.according to a research report and the former study of the project,we propose the ELISA result should be divided by 4 time to adjust the value to meet with HPLC values.After correction,the average benzopyrene of ELISA was 5.79±3.75.The difference between paired T test and HPLC was not significant.ELISA data dispersion(SD)was less than HPLC;But there is a lack of correlation.If the ELISA method is used to directly measure the benzo(a)pyrene permissible limit of 10?g/Kg,according to the national edible oil benzo(a)pyrene standard,the benzo(a)pyrene level exceeds 2.2 times.exceeded the sample by 82.1%,exceeded rate of hot-press procedure is 92.6%.If correction by 4 times,The exceeded rate is 20.5% and 23.2%,the exceeded rate of the HPLC method was 12.8%.ELISA is very sensitive to benzopyrenes.The recovery rate of the standard substance [B(?)P] by ELISA was 96.97%,and RSD was 8%.For the ELISA produces higher/overestimated benzopyrene value than HPLC,Benzopyrenes level of all 154 samples were evaluated by the ELISA kit.Benzopyrenes of cold-pressed oil was significantly lower than hot-pressed oil(16.52±7.76,21.34±10.98)(X ±1SD,?g/L),extremely significant(P=0.004),the difference in benzopyrene content between the product and the graded product,the secondary product and the product was extremely significant(P=0.000).Benzopyrenes levels of the oil collected from Inner Mongolia,Shan Xi,Ning Xia and Gan Su were 20.68±11.33,17.76±3.53,17.21±5.53 and 16.57±8.68 respectively,no significantly differences were shown.Contaminants of the oils obtained farm market were significantly higher than that of supermarket and online shop samples.Benzopyrenes of colza,peanut and corn oil are significantly lower.