| Fingerprinting technology with the characteristics of“integrity”and“fuzziness”has been gradually applied to the traceability identification of wine geographical origin and vintage,and the selection of multiple instrumental analysis methods combined with chemometrics methods can obtain more comprehensive"fingerprint"data information of wine to provide scientific and reasonable technical selection and data support for the research of traceability protection of Chinese wine.This paper aims to obtain the characteristics of Cabernet Sauvignon wines from different origins and vintages by fingerprinting techniques including HS-SPME-GC-MS,Electronic nose?E-nose?,Electronic tongue?E-tongue?and Infrared spectroscopy?IR?to construct corresponding odors,tastes and infrared fingerprints,and clarify the correlation between chemical composition and traceability identification to realize the discrimination and traceability of China Cabernet Sauvignon wines from micro and macro,respectively.The major research contents and results are as follows:?1?Cabernet Sauvignon wines from different producing areas?HBSC,HBCL,YT,NX?and different years?1992,1994,1995,1996 and 1999?are selected as the research objective.Headspace solid Phase-extraction-gas chromatography-mass spectrometry?HS-SPME-GC-MS?was used to screen the characteristic fingerprint information of volatile aroma components as reference such as the main physical and chemical indicators?alcohol,total sugar,total acid and total phenol?.To initially explore the analysis of the geographical origin and vintage recognition mechanism of the Chinese Cabernet Sauvignon wine,the microscopic difference of typical volatility in the composition and relative content of the fragrant substances are obtained.A total of 59volatile aroma compounds,including alcohols?11 species?,acids?3 types?,esters?26types?,aldehyde ketone phenol compounds?10 types?,and other types of compounds?9 types?,were identified in the sample wine at the producing area.Among them,there were 19 volatile aroma components in the producing areas,accounting for 86.44%?HBSC??91.46%?HBCL??95.15%?YT??80.26%?NX?of the total volatile aroma components in each producing area.Simultaneously,the specific volatile aroma components were determined in each producing area.It can be seen that whether the aroma contribution is higher or lower volatile components,the four production areas have certain differences in their types and relative contents.In the samples with different vintages,49 volatile aroma components were identified,of which the main volatile alcohols were phenylethanol,ethanol,isoamyl alcohol and 2-methyl-1-Butanol,and the main volatile esters were ethyl octanoate,diethyl succinate,isoamyl acetate and ethyl acetate.With the increase of aging time,the total content of main alcohol compounds shows a downward trend which the 61.41%in 1999 decreased to 57.42%in 1992.While the total content of major esters increased substantially from 29.33%to32.83%.?2?The macroscopic odor and taste fingerprint of Cabernet Sauvignon wines from different producing areas and years were constructed by E-nose and E-tongue technology.Furthermore,the PCA,DFA and SIMCA traceability models were established by combining chemometric methods.In the traceability of origin,the sum of PC1,PC2 and PC3 in the principal component analysis based on E-nose and E-tongue is 99.9%and 92.774%,which can generally reflect the total difference of wine samples in the production area.Furthermore,established SIMCA models in each production area show that the rejection rates of HBCL and YT are all?98.In the vintage identification,the PCA models show that the sum of PC1 and PC2 based on E-nose and E-tongue are 96.834%and 94.67%,respectively,which can represent most of the information of the selected wine samples.In the SIMCA classification models,the rejection rate of the five vintage samples was?91.Through the comparison of the origins and vintages traceability results by E-nose and E-tongue,it can be seen that the electronic nose analysis effect is better than the electronic tongue in the production area or the vintage traceability analysis,that is,the difference of the volatile odor of the wine sample is greater than the difference in taste.This result verifies the difference analysis of volatile odor based on GC-MS technology in the second chapter.?3?Macro feature"fingerprint"information of Cabernet Sauvignon wines from different geographical origins and vintages by Fourier transform infrared spectroscopy?FT-IR?,second derivative infrared spectroscopy?SD-IR?and two-dimensional synchronous correlation infrared spectroscopy?2DOS-IR?were extracted.As the increasing resolution of Tri-step infrared spectroscopy,clear distinctions among the four origins samples have been thoroughly visualized due to the fingerprint information,and the correlation between the chemical composition and the traceability of the origin and vintage is further explored according to the infrared spectral peak position identification information.Through the identification system of Tri-step infrared spectroscopy technology,the macroscopic characteristic fingerprint bands of geographical origins were extracted at 1716-1500 cm-1,1275-1200 cm-1 and 940-650cm-1.It can be seen that the four types of production areas show significant differences in the types and contents of amino acids?including their derivatives?,phenolic compounds and their derivatives?including esters?.In the vintage discrimination,the"personality"chemical fingerprint not only contains the above characteristic fingerprint bands,but also contains the differences at 1618 and 1409 cm-1?organic carboxylic acid absorption peak?,1558 cm-1?amino acids and derivatives absorption peak?,1285 and1159 cm-1?aromatic compounds?phenol??,1033 and 1060 cm-1?sugar absorption peak?,etc.Therefore,based on the above extracted characteristic peak and fingerprint band information,the correlation between infrared"fingerprint"and the chemical components of wine samples was further revealed,and the geographical origin and vintage traceability was realized in a comprehensive and holistic manner,could provide scientific basis and reference for the establishment of Chinese cabernet sauvignon wine traceability model and discrimination system. |
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