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Alves, Sheila Cristina Oliveira

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  • Influence of the storage in bottle on the antioxidant activities and related chemical characteristics of wine spirits aged with chestnut staves and micro-oxygenation
    Publication . Alves, Sheila Cristina Oliveira; Lourenço, Sílvia; Anjos, Ofélia; Fernandes, Tiago; Caldeira, Ilda; Catarino, Sofia; Canas, Sara
    Different 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.
  • PLS-R calibration models for wine spirit volatile phenols prediction by near-infrared spectroscopy
    Publication . Anjos, Ofélia; Caldeira, Ilda; Fernandes, Tiago; Pedro, Soraia; Vitória, Cláudia; Alves, Sheila Cristina Oliveira; Catarino, Sofia; Canas, Sara
    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.
  • Uma abordagem sustentável: uso da micro-oxigenação conjugada com aduelas de madeira no envelhecimento de aguardente vínica
    Publication . Alves, Sheila Cristina Oliveira; Lourenço, Sílvia; Fernandes, Tiago; Anjos, Ofélia; Caldeira, Ilda; Canas, Sara; Catarino, Sofia
  • Coumarins in spirit beverages: sources, quantification, and their involvement in quality, quthenticity and food safety
    Publication . Alves, Sheila Cristina Oliveira; Lourenço, Sílvia; Fernandes, Tiago; Canas, Sara
    This comprehensive review is devoted to an under-exploited family of phenolic compounds, the coumarins, and the most relevant strands in which they are involved in some spirit beverages—wine spirit, brandy, whiskey, sugar-cane spirits (rum and cachaça) and grape marc spirit—with great importance worldwide in terms of production, trade and consumption. It gathers the key discoveries on the topic, considering the production process of each spirit beverage, and the related sources of coumarins (different kinds of wood used in the ageing stage), along with the factors that govern them and can influence the sensory properties of the aged beverages. An overview of the analytical methods available for their identification/quantification is also included, as well as the corresponding trends for the advancement of knowledge in this field. Moreover, the remarkable role of coumarins as nutraceuticals, their importance as chemical markers for authenticity purposes, and their relationship with the food safety of these spirit beverages are also addressed, highlighting the current gaps and issues, and providing clues for future research.