Study On Intelligent Sensory Characterization Method Of Zhenjiang Aromatic Vinegar Flavor

Zhenjiang aromatic vinegar is one of the four famous vinegars in China.It is well-known at home and abroad for its characteristics of "color,fragrance,acid,alcohol and concentration".How to establish an objective,accurate and complete flavor characterization system to comprehensively determine the flavor of aromatic vinegar not only helps consumers to make better choices,but also helps us to deepen our understanding of the comprehensive characteristics of Zhenjiang aromatic vinegar flavor.In this study,electronic nose and electronic tongue technology were used to detect aromatic vinegar of different ages and characterize its aroma and taste information,so as to establish an intelligent sensory characterization system for the flavor of aromatic vinegar.The main contents of this study are:1.Detection of physical and chemical indicators and artificial sensory evaluation of vinegar(1)Gas chromatography-mass spectrometer(GC-MS)was used to analyze the aroma of each vinegar-aged vinegar,the content of aroma components of fruit and nut scent was determined,provide a comparison for the electronic nose to predict the main aromas of aromatic vinegar.The national standard method was used to determine the content of four characteristic taste substances such as total acid,reducing sugar,salt and amino acid nitrogen of each vinegar-aged vinegar,which provided a comparison for predicting the characteristic taste of aromatic vinegar by electronic tongue.(2)Artificial sensory evaluation of aromatic vinegar of different ages was carried out by quantitative description analysis,the scores obtained are used to provide a comparison and establish correlations in the later use of the intelligent sensory evaluation system.2.Quantitative detection of the main aromas of Zhenjiang aromatic vinegar based on electronic nose(1)According to the results of GC-MS analysis of each vinegar-age aromatic vinegar,twelve electronic nose sensors were screened out.Finally,nine sensors were used to form an electronic nose sensor array for the detection of vinegar aroma information.(2)A quantitative prediction model for the main aromas of aromatic vinegar based on aroma information was established.The electronic nose signals of each vinegar-aged vinegar were collected to establish a quantitative prediction models of the two main aromas of the fruity and nutty scents of aromatic vinegar.Among them,the Partial least square(PLS)prediction model of fruity scent predicts that the Rp is 0.6949 and the RMSEP is 0.5659.The PLS prediction model of nutty scent predicts that the Rp is 0.9427 and the RMSEP is 10.3939.The support vector machine(SVM)predictive model of fruity scent predicts that the Rp is 0.5766 and the RMSEP is 5.0790.The SVM prediction model of nutty scent predicts that the Rp is 0.7557 and the RMSEP is 44.9680.The results showed that the electronic nose technology was feasible to be used to quantitatively predict the main aroma content of Zhenjiang aromatic vinegar.The effect of the established PLS models were better than that of the SVM models.3.Quantitative detection of the characteristic taste substances of Zhenjiang aromatic vinegar based on electronic tongueThe electronic tongue signal of each vinegar-aged vinegar was collected to establish quantitative prediction models of the four characteristic taste substances of the vinegar.Among them,in the constructed PLS prediction model,the total acid had an Rp of 0.9623 and an RMSEP of 0.1197.The reducing sugar had an Rp of 0.9152 and an RMSEP of 0.0975.The salt had an Rp of 0.6420 and an RMSEP of 0.1952.The amino acid nitrogen had an Rp of 0.9611 and an RMSEP of 0.0559.In the constructed SVM prediction model,the Rp of the total acid was 0.9781 and the RMSEP was 6.2818.The reducing sugar had an Rp of 0.9844 and an RMSEP of 2.6434.The Rp of the salt was 0.8792 and the RMSEP was 2.0252.The amino acid nitrogen has an Rp of 0.9614 and an RMSEP of 0.5994.The results show that it is feasible to quantitatively predict the characteristic taste of aromatic vinegar by the electronic tongue,the SVM model has higher correlation but less stability than the PLS model when predicting total acid,reducing sugar and amino nitrogen.When predicting salt,the SVM model correlation is much higher than that of the PLS model.4.Research on intelligent sensory evaluation system of Zhenjiang aromatic vinegar based on electronic nose and electronic tongueEstablish an intelligent sensory evaluation system for aromatic vinegar based on electronic nose and electronic tongue technology.The evaluation indicators include fruitty scent,nutty scent,sourness,sweetness,saltiness and umami.According to the prediction,the corresponding flavor content should be scored.Methods were evaluated to verify the accuracy of the intelligent sensory evaluation system against the results of artificial sensory scores.The results show that the established system has high consistency with artificial sensory evaluation results,which can be applied to actual sensory evaluation.In this study,the physical and chemical indicators of the aroma and taste of aromatic vinegar were used as a control.The electronic nose and electronic tongue technology were used to quantitatively predict the flavor comtent,and good results were obtained.This study demonstrates the application feasibility of intelligent sensory evaluation system based on electronic nose and electronic tongue technology in aromatic vinegar flavor characterization.The research results can provide theoretical support and experimental basis for the application of intelligent sensory evaluation system to actual production.