Simultaneous Determination of Ethanol and Methanol in Wines Using FTIR and PLS Regression.

Accurate quantification of ethanol and methanol is essential for regulatory compliance and product quality assurance. Fourier Transform Infrared Spectroscopy (FTIR) offers rapid, non-destructive analysis with minimal sample preparation, making it a promising tool for wine analysis. In this exploratory study, the use of FTIR and PLS regression for the simultaneous quantification of ethanol and methanol in wine samples of 11 different Portuguese mono-varietal wines and different vintages deriving from the same winery in Lisbon was investigated.

First Approach to the Aroma Characterization of Monovarietal Red Wines Produced from Varieties Better Adapted to Abiotic Stresses.

Adaptation strategies in the wine sector consist of the use of cultural techniques to limit damages caused by climate change, using, among other resources, varieties better adapted to the scenarios of abiotic stress exacerbation, namely water and thermal stress, as well as those more tolerant to heatwaves. With the intention to determine the aromatic characterization of ten monovarietal wines produced from cultivars with high productive performance in a global warming scenario ('Petit Verdot', 'Marselan', 'Merlot', 'Touriga Franca', 'Syrah', 'Vinhão', 'Bobal', 'Preto Martinho', 'Trincadeira', and 'Alicante Bouschet'), grown in Esporão vineyard (Alentejo, Portugal) and submitted to deficit irrigation (Ks ± 0.5), their aromatic character has been analyzed.

Shedding Light on Metals Release from Chestnut Wood to Wine Spirit Using ICP-MS.

Possible effects caused by mineral elements during wine spirit ageing are diverse. In this study, the evolution of the mineral composition of wine spirit during ageing with chestnut ( Mill.) wood was investigated.

Diversity in L. Fermentations in Association with the Volatile and Sensory Similarities of the Distillates.

The fermentation of L. fruit is traditionally carried out in the production of spirits. The present study followed the spontaneous fermentation of fruit harvested in October and December 2019 by two producers from the central region of Portugal.

Identification of gallotannins and ellagitannins in aged wine spirits: A new perspective using alternative ageing technology and high-resolution mass spectrometry.

This research was focused on identifying gallotannins and ellagitannins degradation pathways to better understand their behavior in complex media such as wine spirits (WS). A WS was aged with chestnut wood staves with three levels of micro-oxygenation, nitrogen, and using wooden barrels. Gallotannins and ellagitannins were identified by LC-ESI-HRMS/MS using a Q-TOF in samples collected at 8, 21, 60, 180, 270, and 365 days of ageing, allowed comparing their relative abundances according to the ageing technology.

Influence of the Storage in Bottle on the Antioxidant Activities and Related Chemical Characteristics of Wine Spirits Aged with Chestnut Staves and Micro-Oxygenation.

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.

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

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) and those obtained from GC-FID quantification after liquid-liquid extraction.

Chemical composition and sensory properties of Albariño wine: Fertigation effects.

Interannual climate variability and management practices, including fertigation, can alter volatile compound concentrations in wines from a given grapevine cultivar. These compounds are highly relevant for wine aroma. The current study aimed to assess the effect of two levels of fertigation on the volatile composition and sensory properties of wines from Albariño grown in two vineyards in NW Spain over three years.

Behaviour of Low Molecular Weight Compounds, Iron and Copper of Wine Spirit Aged with Chestnut Staves under Different Levels of Micro-Oxygenation.

Alternative technologies for a more sustainable wine spirits' ageing have been studied but a lack of knowledge on the effect of oxygenation level remains. This work examined the behaviour of low molecular weight compounds, iron and copper of a wine spirit aged in 50 L demijohns with chestnut wood staves combined with three levels of micro-oxygenation or nitrogen. Compounds and mineral elements were quantified by HPLC and FAAS, respectively, in samples collected at 8, 21, 60, 180, 270 and 365 days of ageing.

Effect of innovative technology using staves and micro-oxygenation on the odorant and sensory profile of aged wine spirit.

The aged wine spirit is a beverage with great aromatic complexity. Their volatile compounds with odorant power coming from the distillate and from the wood used in its ageing, and the interactions that take place in the process, enhanced by oxygen, all contribute to this complexity. Due to time and cost inherent of ageing wine spirits in wooden barrels, research has sought to develop more sustainable alternatives to do it.

FT-RAMAN methodology for the monitoring of honeys' spirit distillation process.

Honey spirit is an alcoholic beverage produced by fermentation followed by distillation of the honey must, which has distinct organoleptic characteristics derived mostly from the raw material used. In order to accurately monitor the quality of the product throughout the distillation process (head, heart and tail stages), FT-RAMAN spectroscopy was applied. Dark honey, light honey and honey obtained following waxes' wash was used to produce honey spirit.

Physicochemical and Sensorial Characterization of Honey Spirits.

Distilled spirits are usually made from fermented sugar-based materials, such as wines or fermented fruits, but other products can be used, namely berries or honey. In this work, an evaluation of honey spirits is done based on its physicochemical and sensory characteristics. Fourteen honey spirit samples of different brands of honey spirit were purchased at the market and from artisan Portuguese producers.

Development of blueberry liquor: influence of distillate, sweetener and fruit quantity.

Background: In this work different formulations of blueberry liquor were tested and characterised based on their physico-chemical and sensory characteristics.

Results: Three factors were evaluated: the distillate used to produce the liquor (wine spirit or grape marc spirit); the sweetener (white sugar or honey) and the fruit quantity (two doses). For each liquor, pH, total acidity, dry soluble solids content, dry extract, alcoholic strength, reducing sugars, colour intensity, methanol content, acetaldehyde and fusel alcohols were determined.

Kinetics of odorant compounds in wine brandies aged in different systems.

The odorants compounds of aged wine brandies comprise compounds deriving from the wood, from the distillate and from the reactions that occur inside the barrel. The aim of this work was to study the kinetics of the odorant compounds of a wine brandy during two years of ageing in two ageing systems. The odorant compounds in the analysed brandies changed significantly over the time, but with different evolution patterns.

FTIR-ATR spectroscopy applied to quality control of grape-derived spirits.

The Fourier transform infrared (FTIR) spectroscopic method with attenuated total reflectance (ATR) was used for predicting the alcoholic strength, the methanol, acetaldehyde and fusel alcohols content of grape-derived spirits. FTIR-ATR spectrum in the mid-IR region (4000-400 cm(-1)) was used for the quantitative estimation by applying partial least square (PLS) regression models and the results were correlated with those obtained from reference methods. In the developed method, a cross-validation with 50% of the samples was used for PLS analysis along with a validation test set with 50% of the remaining samples.

Extraction/oxidation kinetics of low molecular weight compounds in wine brandy resulting from different ageing technologies.

This study provides innovative information on the influence of new technologies of ageing (stainless steel tanks with wood staves or wood tablets of chestnut or Limousin oak), in comparison with traditional technology (oak wooden barrels), on the extraction/oxidation kinetics of low molecular weight compounds of wine brandy. The brandy was sampled and analysed by HPLC during the first year of ageing. The results show that most of the compounds tend to increase over the time, but their extraction/oxidation kinetics depend on the ageing technology.

Reactivity of polymeric proanthocyanidins toward salivary proteins and their contribution to young red wine astringency.

Recent studies have indicated the presence of significant amount of highly polymerized and soluble proanthocyanidins in red wine and such compounds interacted readily with proteins, suggesting that they might be particularly astringent. Thus, the objective of this work was to verify the astringency of polymeric proanthocyanidins and their contribution to red wine astringency. The precipitation reactions of the purified oligomeric procyanidins (degree of polymerization ranging from 2 to 12-15) and polymeric procyanidins (degree of polymerization ranging from 12-15 to 32-34) with human salivary proteins were studied; salivary proteins composition changes before and after the reaction was verified by SDS-PAGE and procyanidins composition changes by spectrometric, direct HPLC and thiolysis-HPLC methods.

Sensory and chemical modifications of wine-brandy aged with chestnut and oak wood fragments in comparison to wooden barrels.

Wooden barrels are used in the ageing or maturation of many alcoholic beverages, namely brandies and wines. However, the high costs related to ageing in wooden barrels have led to a search for alternative technologies. In this study we examined the application of wood fragments to the beverage in order to promote an accelerated ageing.