Combination of visible and mid-infrared spectra for the prediction of chemical parameters of wines

Abstract

a b s t r a c tRapid and environmentally friendly methods for the prediction of chemical compositions have been an interest in the wine industry. The objective of the study was to show the potentials of combined use of visible and mid-infrared (MIR) spectroscopies to improve the prediction of various chemical compounds of wine as opposed to using mid-infrared range only. Wine samples of twelve grape varieties from two harvest years were analyzed. The chemical composition of wine samples was related to MIR and visible spectra using orthogonal partial least square (OPLS) regression technique. The prediction abilities were tested with crossvalidation and independent validation sets. The coefficient of determination of validation (R 2 val ) for anthocyanin compounds of red wines were between 0.76 and 0.90, and that for total phenol content was 0.90. Range of R 2 val for glycerol, glycerol/ethanol ratio, malic acid, o-coumaric acid and°B rix were between 0.77 and 0.96. The spectral ranges that played significant roles in the predictions were also determined. The validations with independent data sets showed that the combination of visible and MIR ranges with multivariate methods improved the prediction of anthocyanin compounds and total phenols; produced comparable results for the rest of the parameters as MIR. This is the first study in the literature that shows the practical use of visible spectra along MIR. The combined use of these spectral ranges with multivariate models can be applied for the rapid, on-line determination of quality parameters and chemical profiles of wines.

Hyperspectral Imaging to Characterize Table Grapes

“…RC methods were already reported to be relevant to predict sugar content in the case of lychee fruit [55] and the total polyphenols concentration in cocoa beans [60,63]. Sen and co-workers [64] have also applied VIP selection to build OPLS models for the prediction of chemical parameters of wine by combined use of visible and mid-infrared (MIR) spectroscopies. These authors have built models able to predict anthocyanin compounds, total phenol content, and TSS of red wine with R 2 val ranging between 0.77 and 0.96.…”

“…These authors have built models able to predict anthocyanin compounds, total phenol content, and TSS of red wine with R 2 val ranging between 0.77 and 0.96. The use of VIP in a PLR model (specific windows) was applied by Sen and coworkers [64] to build OPLS models for the prediction of chemical parameters of wine by combined use of visible and mid-infrared (MIR) spectroscopies. These authors have built models able to predict anthocyanin compounds, total phenol content, and TSS of red wine with R 2 val ranging between 0.77 and 0.96.…”

The Application of State-of-the-Art Analytic Tools (Biosensors and Spectroscopy) in Beverage and Food Fermentation Process Monitoring

“…Currently, there are a number of dedicated NIR-based alcohol analysers, and this technique has become a routine analytical method for the determination of alcohol content in wine and other alcoholic beverages [84][85][86][87][88]. The use of NIR spectroscopy has also been reported for the measurement of several chemical parameters in wine and other alcoholic beverages, such as volatile acidity [89,90], organic acids [91][92][93], glycerol [94,95], reducing sugars [96,97], sulphur dioxide [98], and minerals [99,100]. With more recent developments in instrument design and sample presentation modes such as short path-length transmission cells and attenuated total reflectance modules (ATR), the use of both Fourier transformed mid-infrared (FT-MIR or FTIR) and NIR spectroscopy have been reported by several authors and implemented for the routine analysis of a large number of beer and wine parameters such as alcohol content [101,102], volatile acidity [103], dry extract [104], sugars and acids [105], glycerol [106], anthocyanins [107], polyphenols [108], and amino-nitrogen [109], among others.…”

Uso da Espectroscopia de Infravermelho Médio com Transformada de Fourier (IV-TF) aliada à quimiometria para classificação de vinhos e suco de uva

“…Segundo Sen et al (2016) as técnicas de espectroscopia no visível e infravermelho médio (MIR) associadas a técnicas de PLS, permitem acompanhar a variação no teor de compostos fenólicos durante as fases de produção, incluindo o processo de envelhecimento. Silva et al (2014) usando dados da FTIR-ATR aliada a técnicas quimiométricas desenvolveram um método de calibração para diferentes tipos de vinhos que permite estimar o teor de compostos fenólicos, flavonoides e atividade antioxidante.…”