基于化学分析和智能感官方法对不同产地川醋特征风味物质的比较分析(英文)

Evaluation of the Flavor Characteristics of Vinegar from Different Sichuan Regions Based on Chemical Analysis and Intelligent Sensory

研究通过化学分子分析和智能感官等方法对四川不同产地晒醋品质进行比较分析。采用氨基酸自动分析仪、高效液相色谱(HPLC)、固相微萃取气相色谱与质谱联用(SPME-GC-MS)等化学分析方法对样品氨基酸、有机酸、挥发性有机物(VOCs)的种类和含量进行测定分析。通过感官评价,利用电子鼻、电子舌等智能感官结合主成分分析(PCA)和聚类分析(CA)进行表征。结果表明,四种川醋pH3.08~3.29,总酸度16.40%~18.07%,色泽中a*和b*有显著差异(P<0.05);共检出17种氨基酸,其中,丙氨酸和谷氨酸含量最高;测定乙酸、酒石酸等9种有机酸,总含量在22.44~70.06 mg/mL,其中,乙酸和乳酸占总有机酸的50%以上,自贡醋样品的有机酸含量最高(70.06 mg/mL);共检出150多种挥发性有机化合物,其中,酸类(21.56%~44.34%)含量最丰富,眉山醋样中酯类和苯二氮类化合物等种类和相对含量较高;电子鼻、电子舌PCA的前两个主成分之和超过累计方差的98%,电子鼻CA分析显示自贡和眉山醋样差异较大,可能与其感官评价中的涩味及挥发性有机物中酮类、杂环类等的数量有关,电子舌CA分析显示自贡与眉山和南充醋样差异较大,则可能是由pH、总氨基酸、必需氨基酸、有机酸和总酸的差异引起的。通过化学分析、感官分析、智能感官评价结合化学计量法,可以用来表征样品因原料、工艺、配方等因素引起差异的相关性。本研究为建立可靠的中国食醋风味表征提供实用参考,为食醋质量和真实性评价提供了有效依据。

The objective of this study was to compare and analyze the quality of four kinds of traditional vinegar from Sichuan Province.Through chemical analysis methods such as automatic amino acid analyzer,high-phase liquid chromatography(HPLC) and solid-phase microextraction gas-phase-mass-spectrometry(SPME-GC-MS) technologies were used to determine and analyze the types and contents of amino acids,organic acids,and volatile organic compounds(VOCs).Finally,in addition to sensory analysis,intelligent sensory such as electronic nose and electronic tongue combined with principal component analysis(PCA) and cluster analysis(CA) were used for characterization.The results showed that:The pH and total acid ranges of the Sichuan vinegar samples were from 3.08 to 3.29,and 16.40% to 18.07%,respectively.The color parameter a* and b* values were tested to be significantly different(P<0.05).A total of 17 kinds of amino acids were detected,of which alanine and glutamic acid had the highest content.Among 9 organic acids tested,including acetic acid and tartaric acid,the total organic acid content was 22.44~70.06 mg/mL,of which acetic acid and lactic acid accounted for more than 50% of the total organic acids,and Zigong vinegar had the highest organic acid content(70.06 mg/mL).More than 150 volatile organic compounds were detected in the experiment,of which acids(21.56%~44.34%) were the most abundant.It was found that the types and relative contents of unique flavor substances in traditional Chinese vinegar,such as esters and benzodiazepines,were found in Meishan vinegar,and it was significantly higher than Zigong and Nanchong vinegar samples.The sum of the first two principal components of PCA of electronic nose and electronic tongue was more than 98% of the cumulative variance.The difference of CA analysis between Zigong vinegar and Meishan vinegar was mainly due to the degree of astringency in sensory evaluation and the number of ketones and heterocycles in volatile organic compounds.The difference of CA of electronic tongue was mainly caused by the difference of pH,total amino acid,essential amino acid,organic acid and total acid between Zigong,Meishan and Nanchong vinegar.Chemical analysis,sensory evaluation and intelligent sensory combined with chemometric method can be used to characterize the correlation of four Sichuan vinegar samples due to differences in raw materials,processes,formulas,etc.This article can provide a practical reference for establishing a reliable characterization of Chinese vinegar,provide an effective tool for the evaluation of vinegar quality and authenticity,and help to understand the relationship between the internal and external quality characteristics of vinegar.