| Grape seed oil,a new resource of oil derived from grape seed,contains abundant active substances such as vitamin E,squalene,polyphenols,sterols and pigments.Few study was focused on the systematic basic research of grape seed oil.A rapid HPLC-UV-ELSD method for the simultaneous determination of vitamin E,sterol and squalene in grape seed oil was established.The fatty acids,volatile components,polyphenols and unsaponifiable compounds(vitamin E,sterol,squalene)of grape seed oil from different varieties and regions were studied.The multivariate fingerprint was established and the principal component analysis was used to find the characteristic components to preliminary realize the differentiation of variety and origin of grape seed oil.The free radical scavenging ability of grape seed oil was evaluated,and the main antioxidant components in grape seed oil were found by multiple regression analysis.The main contents of the study are as follows:A rapid method for simultaneous determination of tocopherol,tocotrienols,stigmasterol,campesterol,β-sitosterol,sitostanol,squalene in grape seed oil by HPLC tandem Ultraviolet Detector and Evaporative Light-Scattering Detector was established.Through single factor experiment,saponification extraction conditions were optimized.The optimal extraction method was: 3 mol/L alkaline solution,1:15 material to liquid ratio,the addition ratio of TBHQ solution 1:15 and the added concentration 0.5%(w/v).The saponification was operated at 80°C,for 45 min.The linear regression coefficients of the optimized rapid determining method were all greater than 0.999.The detection limit of vitamin E,sterol and squalene was 0.10~5.00 μg/m L,and the quantitative limit of LOQ was 0.17~6.25 μg/m L.The intra-RSD of retention time was 0.33%~5.08%,the extra-RSD of retention time was 0.32%~7.57%.The intra-RSD of peak area was 0.61%~7.96%,and the extra-RSD of peak area was 0.57%~8.52%.The recovery rate was 83.30%~106.80%.The method has good linearity,wide range and high sensitivity.It is suitable for quantitative analysis of 11 trace components in grape seed oil.The content differences of fatty acids,polyphenols,unsaponifiable compounds and volatile components in grape seed oil were studied.The results showed that the main fatty acid composition of grape seed oil was linoleic acid(53.06%~71.46%),oleic acid(10.02%~18.39%),palmitic acid(4.87%~7.00%),stearic acid(1.67%~4.27%),α-linolenic acid(0.12%~0.44%).Grape seed oil contains a variety of active substances.The total polyphenols content was 26.41~185.62 mg/kg.The content of total vitamin E was 267.22~682.44 mg/kg.The total sterol content was 621.18~3590.10 mg/kg.The content of squalene was 6.81~114.38 mg/kg.Qualitative analysis of polyphenols were detected by mass spectrometry.The main polyphenols in grape seed oil were quercetin,vanillic acid,ferulic acid,p-coumaric acid,protocatechualdehyde,protocatechuic acid,catechin and epicatechin gallate.The common peaks of 23 volatile flavor substances were detected in the grape seed oil.It was found that there was a great difference in the variety and content of grape seed oil from different regions.The free radical scavenging ability of the polar part of grape seed oil and the whole oil solution were evaluated.The free radical scavenging ability of grape seed oil was found to be 97.98~144.26 μmol TE/100 g oil.The correlation of vitamin E,sterol,squalene and total polyphenol in grape seed oil with scavenging free radical ability was studied.The multivariate stepwise regression analysis with SPSS software showed that α-tocotrienol,β-sitosterol and total polyphenol were the main antioxidative components in grape seed oil.The multivariate fingerprint with dual wavelength fusion was constructed,and the similarity analysis showed that the constructed multivariate fingerprint was in accordance with the requirements of quality specification.By principal component analysis,grape seed oil from different varieties from Xinjiang and different regions of Cabernet Sauvignon can be easily distinguished. |
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