The Study On The Identification Technology Of Wine Origin And Variety Authenticity

The authenticity identification of the geographical origins and grape varieties of Chinese wines is an urgent technical problem for the wine industry,which need to be solved.Counterfeiting not only seriously disrupts the normal market economy,infringes the rights and interests of consumers,but also poses a potential threat to the health of consumers,causing consumers'trust crisis to the wine industry and the government.Therefore the authentication technology of Chinese wine authenticity is of great importance for Chinese wine industrial conventional quality control and regulatory enforcement.Non-targeted ¹H NMR technology is a fast,convenient,simple and non-destructive detection method,which has been successfully applied to the authenticity identification of wines,fruit juices and honey products abroad.The purpose of this paper is to develop the method for the determination of Chinese wines by ¹H NMR,to build a non-targeted¹H NMR fingerprinting recognition technology models of Chinese wine authenticity combined with multivariate stastical technology,to solve the problem of lack of technical means to identify the labeled geographical origins and grape varieties of Chinese wines,and to provide technical support for the construction of the technical standards and supervision system of Chinese wine authenticity.Through a series of technical studies,the following main results are obtained:?1?In order to screen whether the wine sample is spoiled?GB15037-2006stipulates that the volatile acid content of wine is not more than 1.2 g/L?.A novel method for the rapid determination of volatile acid in wine was developed.By optimizing the distillation program of the wine,the method is shortened from 30minutes to 5 minutes;the recovery rate of this method was 94.87%and the inter-day and intra-day precision of this method were 1.01%and 1.32%,respectively.Good reproducibility was achieved.Volatile acid content in dry,semi dry,semi sweet and sweet wine was measured using this novel method.The results showed no significant difference compared with the national standard method?p>0.05?.This novel method is simple,accurate and fast?The detection time of a single sample was shortened by 20minutes?,and provide the rapid screening for the sour wine samples.?2?A fingerprinting method for the rapid determination of wine by using ¹H NMR was developed.Pulse sequence?NOESYGPPS1D.COMP 1?was used for the multiple suppression of the water signal?4.8 ppm?and the ethanol signals?1.2 ppm and 3.6 ppm?.The parameters of Pulse sequence was optimized to effectively reduce the interference of water and ethanol on the detection of wine samples.¹H NMR fingerprinting technology combined with pulse-length-based concentration?PULCON?was used to quantify the content of acetic acid in wine samples.?3?Identification models were built to verify the authenticity of Chinese wine varieties and geographical origins.Wine samples from three distinctive geographical origins?Shacheng,Changli and Changji?including three grape varieties of red wines?Cabernet Sauvignon,Rose Honey,Cabernet Gernischt?and white wines?Ugni Blanc,Long Yan,Chardonnay?were measured by non-targeted ¹H NMR spectroscopy fingerprinting technology.A segment-wise peak alignment was employed to handle peak misalignments of recorded ¹H NMR spectra.Binning of the aligned ¹H NMR spectra was performed for data reduction.The resulting bins were employed as input variables for the subsequent multivariate statistical analysis.Principal component analysis?PCA?combined with linear discriminant analysis?LDA?using internal leave one-out cross validation were employed to establish the identification model of the three geographical origins and six grape varieties.Accurate classification rates for the wine samples of Shacheng,Changli and Changji were 92%,73%,68%,respectively.The average correct classification rates of Shacheng,Changli and Changji wine samples were determined to 78%.The correct classification rates of Cabernet Sauvignon,Rose Honey and Cabernet Gernischt?red wine varieties?were 68%,100%and 81%.The correct classification rates of Ugni Blanc,Long Yan and Chardonnay?white wine varieties?were 93%,95%and 94%.The average correct classification rates of red and white wine varieties were determined to 82%and 94%.Principal component analysis?PCA?combined with random forest?RF?using internal leave one-out cross validation were employed to establish the discrimination model of the six grape varieties.The correct classification rates of Cabernet Sauvignon,Rose Honey and Cabernet Gernischt?red wine varieties?were 75%,100%and 82%.The correct classification rates of Ugni Blanc,Long Yan and Chardonnay?white wine varieties?were 93%,81%and 89%.The average correct classification rates of red and white wine varieties were determined to85%and 89%.In order to avoid the overfitting,repeated double random cross validation methods was used to verify the validity of the PCA/LDA and PCA/RF models.This results demonstrated that non-targeted ¹H NMR spectroscopy combined with multivariate analysis is an effective tool to verify the authenticity of Chinese wine.ICP-MS,ICP-OES and IRMS are used to detect a variety of inorganic elements and oxygen isotope ratio(?¹⁸O)in wine,respectively.Combined with multivariate analysis,the feasibility of verifying the authenticity of geographical origins of Chinese wine was investigated using targeted fingerprinting technology.?1?The elemental profile and oxygen isotope ratio(?¹⁸O)of wine samples collected from the Changji,Mile,and Changli regions in China were analysed by inductively coupled plasma mass spectrometry?ICP-MS?,inductively coupled plasma optical emission spectroscopy?ICP-OES?and isotope ratio mass spectrometry?IRMS?,respectively.By combining the data of?¹⁸O and the concentration data of 52 elements,the analysis of variance?ANOVA?technique was firstly applied to obtain the important descriptors for the discrimination of the three geographical origins.Ca,Al,Mg,B,Fe,K,Rb,Mn,Na,P,Co,Ga,As,Sr,and?¹⁸O were identified as the key explanatory factors.In the second step,the key elements were employed as input variables for the subsequent partial least squares discrimination analysis?PLS-DA?and support vector machine?SVM?analyses.The average correct classification rates of the wine samples of Shacheng,Changli and Changji by using the PLS-DA and SVM models were determined to 96%,97%,respectively.In order to avoid the overfitting,repeated double random cross validation methods was used to verify the validity of the PLS-DA and SVM models.Thus,it was suggested that the combination of oxygen isotope ratio(?¹⁸O)and elemental profile with multi-step multivariate analysis is a promising approach for the verification of the considered three geographical origins of Chinese wines.Comparison of the average correct classification rates for verifying the geographical origins of wine samples by using the non-targeted ¹H NMR and targeted fingerprinting technology,the results showed that the average correct classification rates for verifying the geographical origins of wine samples by targeted fingerprinting technology was 96%,obviously much higher than 78%by using the non-targeted ¹H NMR fingerprinting technique.However,the non-targeted ¹H NMR fingerprinting technique can be used to identify the grape varieties of wines,but the fingerprinting technique can not do it based on the current research results of this study.In conclusion,wine matrix and counterfeiters are sophisticated,only by combining targeted and non-targeted fingerprinting technology,can we provide different levels of technical support for wine authenticity identification,and establish reliable wine authenticity identification models.