Effect of different pre-fermentation treatments on polyphenols, color, and volatile compounds of three wine varieties

Comprehensive Analysis of Physicochemical Properties and Volatile Compounds in Different Strawberry Wines under Various Pre-Treatments

Pre-fermentation treatment has an important impact on the color, aroma, taste, and other characteristics of fruit wine. To discover suitable pre-treatment techniques and conditions that yield strawberry wine of excellent quality, the influences of juice fermentation, pulp maceration, thermovinification, and enzymatic hydrolysis pre-treatments on the basic chemical composition, color, antioxidant capacity, and volatile organic compounds in strawberry wines were investigated. The results showed that the color, antioxidant properties, and volatile aroma of strawberry wines fermented with juice were different from those with pulp. Strawberry wines fermented from juice after 50 °C maceration had more desirable qualities, such as less methanol content (72.43 ± 2.14 mg/L) compared with pulp-fermented wines (88.16 ± 7.52 mg/L) and enzymatic maceration wines (136.72 ± 11.5 mg/L); higher total phenolic content (21.78%) and total flavonoid content (13.02%); enhanced DPPH (17.36%) and ABTS (27.55%) free radical scavenging activities; richer essential terpenoids and fatty acid ethyl esters, such as linalool (11.28%), ethyl hexanoate (14.41%), ethyl octanoate (17.12%), ethyl decanoate (32.49%), and ethyl 9-decenoate (60.64%); pleasant floral and fruity notes compared with juice-fermented wines macerated at normal temperatures; and a lighter color. Overall, juice thermovinification at 50 °C is a potential pre-treatment technique to enhance the nutrition and aroma of strawberry wine.

White wine phenolics: current methods of analysis

White wine phenolic analyses are less common in the literature than analyses of red wine phenolics. Analytical techniques for white wine phenolic analyses using spectrophotometric, chromatographic, spectroscopic, and electrochemical methods are reported. The interest of research in this area combined with the advances in technology aimed at the winemaking industry are promoting the establishment of novel approaches for identifying, quantifying, and classifying phenolic compounds in white wine. This review article provides an overview of the current research into white wine phenolics through a critical discussion of the analytical methods employed. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Fast and Reliable Multiresidue Analysis of Aromas in Wine by Means of Gas Chromatography Coupled with Triple Quadrupole Mass Spectrometry

The paper would like to show a direct injection into GC-MS/QqQ for the determination of secondary aromas in white wine samples fermented in two different ways. The procedure has been compared with more traditional methods used in this field, i.e., headspace analysis and liquid–liquid extraction. The application of such direct injection, for the first time in the literature, allows us to analyze Volatile Organic Compounds (VOCs) in the range 0.1–100 µg mL−1, with Limits of Detection (LODs) and Limits of Quantification (LOQs) between 0.01–0.05 µg mL−1 and 0.03–0.09 µg mL−1, respectively, intraday and interday below 5.6% and 8.5%, respectively, and recoveries above 92% at two different fortification levels. The procedure has been applied to real wine samples: it evidences how the fermentation in wood (cherry) barrel yields higher VOC levels than ones in wine fermented in steel tank, causing production of different secondary aromas and different relative flavors.

Influence of Different Vinification Techniques on Volatile Compounds and the Aromatic Profile of Palomino Fino Wines

The aim of this study was to evaluate the influence of vinification techniques on volatile compounds and sensory profiles in young Palomino fino white wines. Four winemaking techniques (pellicular maceration, supra-extraction and use of commercial yeast strains and of β-glycosidase enzymes) were implemented to enhance the aromatic quality of wines elaborated from this neutral variety of grape. Volatile compound content, aromatic profile (OAVs) and sensorial analysis were determined. The results showed that all the vinification techniques studied led to an increase in volatile compounds compared to the control wine. Likewise, an influence of the vineyard and must extraction method on these compounds was observed. However, the greatest changes in aroma activity and sensory profile were a result of the pellicular maceration and supra-extraction techniques. The latter was differentiated by the highest content of terpenes and, consequently, the highest odour activity values of floral series. In addition, the supra-extraction was a very selective technique since it extracted terpenes and aromatic precursors, but not the acids responsible for the fatty characteristic, such as octanoic acid. In terms of sensory profile, the supra-extraction technique improved the intensity of the Palomino fino white wine and its aromatic quality with a previously not-determined floral character.

Effects of winemaking on ‘Marselan’ red wines: volatile compounds and sensory aspects

Winemaking processes and volatile compounds perform an important role in contributing to the quality of wines. ‘Marselan’ is a red grape variety grown in several countries such as France, Brazil and China. This variety has gained international interest in recent years. The volatile profile of Brazilian ‘Marselan’ red wines during various winemaking processes was studied. Four processes were applied: thermovinification, integrale vinification, classic winemaking and classic winemaking pretreated with ultrasound. The wines were characterized with conventional physicochemical analyses, volatile composition and sensory analysis. Sixty-three volatile compounds were identified and semi-quantified. The wines presented different sensory characteristics. The thermovinification and classic winemaking with ultrasound application methods showed a large presence of esters contributing to a fruity and overmaturation aroma in the volatile profile and sensory analysis. An increased presence of vegetal and sulfurous aromas was observed in the wines from the classic winemaking and integrale vinification processes. This effect was most likely attributed to the lower influence of esters which generated a greater perception of other compounds and conferred these aromas. The differences can be directly linked to the various extraction rates in the vinification processes, which result in different interactions between the compounds.

Polyphenols: Natural Antioxidants to Be Used as a Quality Tool in Wine Authenticity

Polyphenols are a diverse group of compounds possessing various health-promoting properties that are of utmost importance for many wine sensory attributes. Apart from genetic and environmental parameters, the implementation of specific oenological practices as well as the subsequent storage conditions deeply affect the content and nature of the polyphenols present in wine. However, polyphenols are effectively employed in authenticity studies. Provision of authentic wines to the market has always been a prerequisite meaning that the declarations on the wine label should mirror the composition and provenance of this intriguing product. Nonetheless, multiple cases of intentional or unintentional wine mislabeling have been recorded alarming wine consumers who demand for strict controls safeguarding wine authenticity. The emergence of novel platforms employing instrumentation of exceptional selectivity and sensitivity along with the use of advanced chemometrics such as NMR (nuclear magnetic resonance)- and MS (mass spectrometry)-based metabolomics is considered as a powerful asset towards wine authentication.

Effect of different pre-treatment maceration techniques on the content of phenolic compounds and color of Dornfelder wines elaborated in cold climate

This study present the effects of different pre-treatment maceration techniques (microwave, thermo-maceration, and enzymatic treatment) on the content of phenolic compounds (by UPLC-PDA) and their redox potential by cyclic voltammetry (CV), antioxidant capacity (ABTS radical cation decolorization assay and FRAP as Ferric Reducing Ability of Plasma), and other basic chemical properties of red wine made from cv. Dornfelder. The pre-treatment maceration technique significantly (p < 0.05) affected the content of total phenolics in Dornfelder must (freshly crushed grapes), with particularly high amounts in the must pre-treated by microwaves (4344.0 mg/100 mL), and the lowest in the must pre-treatment by thermo-maceration (2979.8 mg/100 mL). A positive correlation was found between the content of total phenolics and antioxidant activity (R = 0.69 and 0.52 by ABTS and FRAP assay, respectively) and individual groups of polyphenols (for ABTS assay with anthocyanins, flavonols, flavan-3-ols, respectively R = 0.60, 0.64 and 0.66, while for FRAP method only for anthocyanins R = 0.79). The highest antioxidant activity was also determined for the variant with microwave pre-treatment (must 3.31 mM and 3.05 mM Trolox/100 mL for ABTS and FRAP assay, respectively). Following the fermentation and maturation, the amount of polyphenols decreased. No thermal pre-treatment maceration methods gave lighter or redder must. After winemaking process all the samples were characterized by less red and more yellow shade.