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- PLS-R calibration models for wine spirit volatile phenols prediction by Near-Infrared SpectroscopyPublication . Anjos, O.; Caldeira, Ilda; Fernandes, Tiago A.; Pedro, Soraia; Vitória, Cláudia; Alves, Sheila Oliveira; Catarino, Sofia; Canas, SaraNear-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-methylsyringol (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.
- PLS-R calibration models for wine spirit volatile phenols prediction by Near-Infrared SpectroscopyPublication . Anjos, O.; Caldeira, Ilda; Fernandes, Tiago A.; Pedro, Soraia; Vitória, Cláudia; Alves, Sheila Oliveira; Catarino, Sofia; Canas, SaraNear-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 cm1) 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-methylsyringol (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.
- Influence of the storage in bottle on the antioxidant activities and related chemical characteristics of wine spirits aged with chestnut staves and micro-oxygenationPublication . Alves, Sheila Oliveira; Lourenço, Sílvia; Anjos, O.; Fernandes, Tiago A.; Caldeira, Ilda; Catarino, Sofia; Canas, SaraDifferent ageing technology of wine spirits (WSs) has been investigated, but little has been published on the chemical evolution of aged WS during storage in bottle. The purpose of this study was to examine how 12 months of storage in bottle affected the evolution of antioxidant activity (DPPH, FRAP and ABTS assays), total phenolic index (TPI) and low molecular weight (LMW) compounds content of the WSs aged through alternative technology using three micro-oxygenation levels (MOX) and nitrogen control (N). Results revealed the ability of phenolic compounds from aged WSs to scavenge free radicals during storage in bottle. Among the in vitro antioxidant-activity methods, FRAP assay was the more effective to differentiate WSs according to the ageing technology. Concerning the overall influence of storage in bottle on antioxidant activity, and TPI and LMW compounds content, the higher results were obtained for the MOX modalities (O15, O30 and O60), which showed a similar evolution. In summary, this study provides innovative information, demonstrating that the differences between the aged WSs imparted throughout the ageing process (resulting from different MOX levels) were mostly retained, and only slight modifications during storage in bottle were found.
- The effect of transition metals on coniferaldehyde oxidation in wine spirits model solutionsPublication . Alves, Sheila Oliveira; Lourenço, Sílvia; Fernandes, Tiago A.; Anjos, O.; Caldeira, Ilda; Catarino, Sofia; Canas, SaraWood is known to be a complex biological system composed mainly of cellulose, hemicelluloses and lignin. Cellulose is commonly degraded by the thermal treatment of wood during coopering giving rise to HMF and 5- methylfurfural, while hemicellulose can generate pentose by hydrolysis, and posteriorly, furfural and its derivatives. Lignin transformations during ageing process of distillates are among the most important factors that may influence the quality of aged wine spirit (WS).
- Application of near-infrared spectroscopy to characterize volatile phenols and sensory profile of aged wine spiritsPublication . Anjos, O.; Caldeira, Ilda; Fernandes, Tiago A.; Pedro, Soraia; Vitória, Cláudia; Alves, Sheila Oliveira; Catarino, Sofia; Canas, SaraVolatile phenols are low molecular weight aromatic alcohols, with particular importance in wine spirits aged with wood due to their strong influence on sensory profile.
- Antioxidant ativities of wine spirits aged by a sustainable technology using chestnut wood staves and micro-oxygenationPublication . Alves, Sheila Oliveira; Lourenço, Sílvia; Anjos, O.; Caldeira, Ilda; Fernandes, Tiago A.; Catarino, Sofia; Canas, SaraAntioxidant ativities of wine spirits aged by a sustainable technology using chestnut wood staves and micro-oxygenation.
- Influence of the storage in bottle on the antioxidant activities and related chemical characteristics of wine spirits aged with chestnut staves and micro-oxygenationPublication . Alves, Sheila Oliveira; Lourenço, Sílvia; Anjos, O.; Fernandes, Tiago A.; Caldeira, Ilda; Catarino, Sofia; Canas, SaraDifferent ageing technology of wine spirits (WSs) has been investigated, but little has been published on the chemical evolution of aged WS during storage in bottle. The purpose of this study was to examine how 12 months of storage in bottle affected the evolution of antioxidantactivity (DPPH, FRAP and ABTS assays), total phenolic index (TPI) and low molecular weight (LMW)compounds content of the WSs aged through alternative technology using three micro-oxygenationlevels (MOX) and nitrogen control (N). Results revealed the ability of phenolic compounds fromaged WSs to scavenge free radicals during storage in bottle. Among the in vitro antioxidant-activity methods, FRAP assay was the more effective to differentiate WSs according to the ageing technology.Concerning the overall influence of storage in bottle on antioxidant activity, and TPI and LMW compoundscontent, the higher results were obtained for the MOX modalities (O15, O30 and O60), whichshowed a similar evolution. In summary, this study provides innovative information, demonstratingthat the differences between the aged WSs imparted throughout the ageing process (resulting from different MOX levels) were mostly retained, and only slight modifications during storage in bottle were found.
- Influence of the storage in bottle on the antioxidant activity of wine spirit aged by sustainable technology of micro-oxygenation with Limousin oak stavesPublication . Alves, Sheila Oliveira; Lourenço, Sílvia; Fernandes, Tiago A.; Anjos, Ofélia; Caldeira, Ilda; Catarino, Sofia; Canas, SaraThe traditional ageing technology (TAT) has always been associated with oak barrels ageing and involves staging the wine distillate (WD) in wooden barrels with a continuous innate diffusion of oxygen through the wood and space between staves, under which the beverage spirit undergoes positive changes that contribute to the enhancement of its chemical composition and sensory properties.
- Application of Near-Infrared Spectroscopy to characterize volatile phenols and sensory profile of aged wine spiritsPublication . Anjos, O.; Caldeira, Ilda; Fernandes, Tiago A.; Pedro, Soraia; Vitória, Cláudia; Alves, Sheila Oliveira; Catarino, Sofia; Canas, SaraApplication of Near-Infrared Spectroscopy to characterize volatile phenols and sensory profile of aged wine spirits.
- Hydrolysable tannins in aged wine spirits: a fresh perspective using alternative ageing technology and high-resolution mass spectrometryPublication . Fernandes, Tiago A.; Antunes, Alexandra M.M.; Alves, Sheila Oliveira; Caldeira, Ilda; Anjos, O.; Catarino, Sofia; Canas, SaraWine spirits (WSs) are usually aged in wooden barrels, but using wood pieces instead of barrels, with or without micro-oxygenation, is a technological alternative that has been investigated by our team.