PLS-R Calibration Models for Wine Spirit Volatile Phenols Prediction by Near-Infrared Spectroscopy

Abstract

Near-infrared spectroscopic (NIR) technique was used, for the first time, to predict volatile phenols content, namely guaiacol, 4-methyl-guaiacol, eugenol, syringol, 4-methyl-syringol and 4-allyl-syringol, of aged wine spirits (AWS). This study aimed to develop calibration models for the volatile phenol’s quantification in AWS, by NIR, faster and without sample preparation. Partial least square regression (PLS-R) models were developed with NIR spectra in the near-IR region (12,500–4000 cm−1) and those obtained from GC-FID quantification after liquid-liquid extraction. In the PLS-R developed method, cross-validation with 50% of the samples along a validation test set with 50% of the remaining samples. The final calibration was performed with 100% of the data. PLS-R models with a good accuracy were obtained for guaiacol (r2 = 96.34; RPD = 5.23), 4-methyl-guaiacol (r2 = 96.1; RPD = 5.07), eugenol (r2 = 96.06; RPD = 5.04), syringol (r2 = 97.32; RPD = 6.11), 4-methyl-syringol (r2 = 95.79; RPD = 4.88) and 4-allyl-syringol (r2 = 95.97; RPD = 4.98). These results reveal that NIR is a valuable technique for the quality control of wine spirits and to predict the volatile phenols content, which contributes to the sensory quality of the spirit beverages.

Using Vis-NIR Spectroscopy for Predicting Quality Compounds in Foods

“…For the first time, this research shows the applicability of NIR spectroscopy to assess volatile phenol contents (guaiacol, 4-methyl-guaiacol, eugenol, syringol 4-methyl-syringol and 4-allyl-syringol) and confirms the ability of this technique to quantify compounds that contribute to the sensory quality of aged wine spirits [11].…”

“…This Special Issue has had a resoundingly enthusiastic response, with several submissions from academics and professional spectroscopists, resulting in a collection of 13 papers, including one exhaustive review paper [8][9][10][11][12][13][14][15][16][17][18][19][20]. The articles submitted represent the variety of the discussed field well, covering a wide range of topics related to NIR spectroscopy.…”

Investigating partial least squares discriminant analysis and hierarchical modelling of short wave infrared hyperspectral imaging data to distinguish production area and quality of rooibos (Aspalathus linearis)

“…11 Regardless of very low concentrations of volatiles in plant products, examples which demonstrate the successful application of NIR spectroscopy and data analytical tools to differentiate between samples of the same product such as wines, whiskey, barley malt and coffee can be found. [16][17][18][19][20] These studies suggest the potential application of these techniques not only to distinguishing between rooibos from different production areas, but also between different quality grades.…”

Theoretical insight of reactive oxygen species scavenging mechanism in lignin waste depolymerization products

“…12,13 Some are known to be used in liquor and perfumery due to unique and pleasant aroma characteristics. [14][15][16][17] In addition, many of them have been proven to possess many biological activities such as antifungal, antibacterial, and antioxidant. 18,19 The versatile antioxidant nature of these compounds enables their potential application in the pharmaceutical industry and other sectors.…”