A Metabolomic Approach to the Study of Wine Micro-Oxygenation

Wine micro-oxygenation is a globally used treatment and its effects were studied here by analysing by untargeted LC-MS the wine metabolomic fingerprint. Eight different procedural variations, marked by the addition of oxygen (four levels) and iron (two levels) were applied to Sangiovese wine, before and after malolactic fermentation

Fast Analysis of Total Polyphenol Content and Antioxidant Activity in Wines and Oenological Tannins Using a Flow Injection System with Tandem Diode Array and Electrochemical Detections

An analytical method for simultaneous determination of total polyphenol content (TPC) and antioxidant activity (AA) of wines (white and red wines) and oenological tannins, using a flow injection system with sequential diode array and electrochemical amperometry detectors (DAD-ECD), was proposed. The signal at 280 nm provided aggregate data for TPC. The anodic peak related to wine phenolic oxidation was scanned using pulsed integrated amperometry over the potential of 800 mV vs. Ag/AgCl, to obtain AA. Serial dilutions avoided the poisoning at the glassy carbon (GC) electrode and the linear response obtained with both detectors was compared with spectrophotometric assays commonly used in oenology laboratory. Intraday and interday analytical repetitions showed a good repeatability and reproducibility (relative standard deviation RSD < 6% for both detectors), and the satisfactory relationship between the proposed coupled flow injection/DAD-ECD and the classic UV methods (R2TPC = 0.9967; R2DPPH = 0.9621) confirmed the efficacy of flow injection analysis with a coupled detection system, for the reliable quality control of wine and wine-related products

Fermentative and post-fermentative oxygenation of Corvina red wine: influence on phenolic and volatile composition, colour and wine oxidative response

BACKGROUND During the production of red wine, moderate uptake of oxygen in the post-fermentative phase helps the stabilization of colour and the decrease of astringent tannins. However, the influence of oxygen uptake during the fermentative phase in must has not been completely investigated. In this study we evaluated the effect of controlled oxygen supply during fermentation-maceration of Corvina grapes on colour characteristics, tannins, volatile compounds, acetaldehyde production and oxidative stability of the finished wine.RESULTS Oxygen supply during fermentation improved the formations of stable pigments of Corvina wines due to the higher production of acetaldehyde. However, in wines treated with oxygen a lower production of fruity esters by yeasts was observed. Wines obtained from higher oxygen exposure during fermentation-maceration showed reduced ability to react with oxygen during storage.CONCLUSIONS Fermentative and post-fermentative oxygenation should be considered as a technological approach for modifying colour composition and stability, as well as oxidative behaviour of wine during aging. (c) 2020 Society of Chemical Industr

Extraction, Evolution, and Sensory Impact of Phenolic Compounds During Red Wine Maceration

We review the extraction into wine and evolution of major phenolic classes of sensory relevance. We present a historical background to highlight that previously established aspects of phenolic extraction and retention into red wine are still subjects of much research. We argue that management of the maceration length is one of the most determining factors in defining the proportion and chemical fate of phenolic compounds in wine. The extraction of anthocyanins, flavonols, flavan-3-ols, and oligomeric and polymeric proanthocyanidins (PAs) is discussed in the context of their individual extraction patterns but also with regard to their interaction with other wine components. The same approach is followed to present the sensory implications of phenolic and phenolic-derived compounds in wine. Overall, we conclude that the chemical diversity of phenolic compounds in grapes is further enhanced as soon as vacuolar and pulp components are released upon crushing, adding a variety of new sensory dimensions to the already present chemical diversity. Polymeric pigments formed by the covalent reaction of anthocyanin and PAs are good candidates to explain some of the observed sensory changes in the color, taste, and mouthfeel attributes of red wines during maceration and aging.EEA MendozaFil: Casassa, Luis Federico. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Centro de Estudios de Enología; Argentina. Washington State University. Irrigated Agriculture Research and Extension Center. School of Food Science; Estados UnidosFil: Harbertson, James F. Washington State University. Irrigated Agriculture Research and Extension Center. School of Food Science; Estados Unido