HS-SPME-GC-MS分析水蛭不同炮制品的腥臭气物质及去腥矫臭机制

HS⁃SPME⁃GC⁃MS Analyses Odor Substances in Different Processed Leech Products and the Mechanism of Removing Stench and Correcting Stink

目的 对水蛭生品、清炒品、滑石粉烫品、酒炙品、醋炙品、酒醋炙品中挥发性成分进行分析比较,探索炮制“去腥矫味矫臭”机制及关键性指标成分。方法 采用顶空-固相微萃取法(HS-SPME)结合气相色谱-质谱技术(GC-MS)对样品进行分析与鉴定,利用峰面积归一化法计算各组分的相对百分含量,结合相对气味活度值(ROAV)分析出关键臭气成分,并利用多元统计方法分析生品与炮制品挥发性成分的差异。结果 从水蛭生品与5种炮制品中分别鉴定出127,122,125,126,129,128种化合物,共有成分121种。确定4-甲基苯酚、2-甲氧基-3-异丁基吡嗪、正己醛、异戊酸等14种成分为水蛭关键性腥臭物质(ROAV≥1);主成分分析(PCA)将生品与不同炮制品显著区分;正交偏最小二乘法(OPLS-DA)显示生品与清炒品、滑石粉烫品、酒炙品、醋炙品、酒醋炙品之间分别存在15,15,12,12,12种差异成分。结论 水蛭经不同的炮制方法进行炮制后,均有“去腥矫味矫臭”效果,其机制复杂,总体概括主要包含3点:与水蛭炮制前后挥发性组分和含量的变化有关;炮制加热过程中发生美拉德反应,产生香味物质;黄酒、米醋等炮制辅料能引入醇类、酯类、氨基酸类等香味物质而掩臭。

OBJECTIVE To analyze and compare the volatile components in raw leeches,fried leeches,scalded talcum powder,roasted leeches with wine,roasted leeches with vinegar,roasted leeches with wine and vinegar,and explore the mechanism and key index components of processing“removing fishy smell and correcting odor”.METHODS HS⁃SPME combined with gas chromatogra⁃phy⁃mass spectrometry(GC⁃MS)was used to analyze and identify the samples,the peak area normalization method was used to calculate the relative percentage of each component,and the key odor components were analyzed by combining the relative odor activity value(ROAV),and the difference of volatile components between raw and processed products was analyzed by multivariate statistical meth⁃od.RESULTS The 127,122,125,126,129 and 128 compounds were identified from the raw leeches and 5 processed leeches,with a total of 121 components.Fourteen components,such as 4⁃methylphenol,2⁃methoxy⁃3⁃isobutyl pyrazine,hexanal and isovaleric acid,were identified as the key odorous substances of leeches(ROAV≥1).Principal component analysis(PCA)distinguished raw products from different processed products.Orthogonal partial least squares⁃discriminant analysis(OPLS⁃DA)showed that there were 15,15,12,12 and 12 different components between raw products and fried products,talcum powder hot products,wine⁃baked prod⁃ucts,vinegar⁃roasted products,wine and vinegar roasted products,respectively.CONCLUSION After different processing methods,leeches all have the effect of“removing fishy smell and correcting odor”,and its mechanism is complex.The general summary mainly includes three points:It is related to the changes of volatile components and contents of leeches before and after processing.Maillard reaction occurs in the process of processing and heating,and aroma substances are produced.Processing auxiliary materials such as yellow rice wine and rice vinegar can introduce aromatic substances such as alcohols,esters and amino acids to mask odor.