Classification of Brazilian vinegars according to their 1H NMR spectra by pattern recognition analysis

Abstract

1 H NMR SIMCA KNN PLS-DA a b s t r a c tThis work describes using 1 H NMR data and pattern recognition analysis to classify vinegars. Vinegar authenticity is linked to raw ingredient source and manufacturing conditions. Application of PCA and HCA methods resulted in the natural clustering of the samples according to the raw material used. Wine vinegars were characterized by a high concentration of ethyl acetate, glycerol, methanol and tartaric acid, while glycerol and ethyl acetate signals were not visible in alcohol/agrin vinegars. Apple vinegars showed to be richer in alanine. The KNN, SIMCA and PLS-DA methods were used to build predictive models for classification of vinegar type wine, apple and alcohol/agrin (27 samples -22 as training set). The models were tested using an independent set (5 samples), no samples were wrongly classified. Validated models were used to predict the class of 21 commercial samples, which, as expected, were correctly classified. Eight commercial vinegars (honey, orange, pineapple and rice) were discriminated from these samples using PCA method. Honey vinegars did not present ethanol signals and pineapple vinegars presented the largest amount of tartaric acid. Rice and orange vinegars are richer in lactic acid and did not present the methanol signal. Alanine signals were not visible in orange vinegars.

NMR spectroscopy evaluation of direct relationship between soils and molecular composition of red wines from Aglianico grapes

“…3-5). Signals identification was further supported by molecular attribution reported in literature for wine 1 H NMR spectra [13,14,16,21,24]. Most of the above compounds are mainly of microbial origin: lactic acid is the metabolic product of malo-lactic fermentation performed by malo-lactic bacteria (MLB) [25]; succinic acid is the major organic acid produced by yeast metabolism [26]; glycerol is the final product of glyceropiruvic fermentation by yeast and its formation accompanies ethanol production in sugar fermentation [27].…”

“…In fact, it was observed that application of a 3 s delay between initial 180 • and second 90 • hard pulse, efficiently suppressed the ethanol multiplets and acetic acid singlet at 2.09 ppm [13,21], while it allowed recovering all other signals without significant intensity loss. In addition, this pulse sequence included a water signal pre-saturation, that resulted in a concomitant removal of both undesired water and ethanol signals ( Supplementary Fig.…”

A Review of Technologies for Detection and Measurement of Adulterants in Cereals and Cereal Products

“…This electromagnetic technique requires sensors with highly sophisticated mathematical models and computer software algorithms that can be harnessed to relate physical or chemical properties and quality attributes of the product in consideration. The combination of PLS-DA and NMR has been successfully used to detect adulterants in several foodstuffs including cereals and cereal products (Boffo et al, 2009;Marcone et al, 2013). PLS-DA is a widely used multivariate technique that uses few latent variables, takes into account the correlation between the variables, filters the noise, and leads to good predictive performance of the model.…”

Determining method, conditional factors, traits and applications of nonlinear chemical fingerprint by using dissipative components in samples

“…At present, the fingerprint technique has become one of people's research hotspots, and there have been some very good research reports. The reports include organic mass spectrum [6][7][8][9], inorganic element [10][11][12][13], biochemistry [14][15][16], HPLC [17,18], GC [18][19][20], CE [21], NMR [7,22], UV [7,23] and IR fingerprints [23][24][25][26][27][28][29], etc. Among the techniques, the application research of chromatographic fingerprint are the most prevalent and in-depth due to its traits of qualitative, quantitative and multidimensional information, and has been used in the fingerprint analyses of extraction solution and volatile components of samples.…”