Does Fungal Chitosan Leave Noticeable Traces in Treated Wines?

The use of fungal chitosan as an antiseptic in wine appears as a promising alternative to sulfur dioxide for the elimination of sensitive strains. Nevertheless, its utilization raises the question, "how are the treated wines different from the untreated ones?" Chitosan treatment residues were sought in the oligosaccharide and polysaccharide fractions and among 224 low MW ions (<1800 g·mol) in several wines by using liquid chromatography (size exclusion HPLC or LC-MS) and GC-MS. Standard oenological parameters were also examined as well as possible sensory modifications by a panel of tasters composed of experts and non-experts.

Grape-Derived Polysaccharide Extracts Rich in Rhamnogalacturonans-II as Potential Modulators of White Wine Flavor Compounds.

Many authors have investigated the role of mannoproteins on wine quality, but very few have analyzed the use of grape-derived polysaccharides as they are not commercially available. In this study, purified grape-derived polysaccharides from red wine (WPP) and winemaking by-products (DWRP: Distilled Washing Residues Polysaccharides) were used as potential fining agents to modulate white wine flavor. Phenolics and volatile compounds were analyzed in the control and wines treated with WPP, DWRP, and commercial mannoproteins (CMs) after one and twelve months of bottling, and a sensory analysis was conducted.

Exploring the influence of S. cerevisiae mannoproteins on wine astringency and color: Impact of their polysaccharide part.

The impact of the polysaccharide moiety of mannoproteins (MPs) on the color and astringency of red wines was studied respectively through spectrophotometry and their impact on tannin interactions with BSA. To this end, MPs with conserved native structures from four different Saccharomyces cerevisiae strains were used: a Wild-Type strain (BY4742, WT) taken as reference, mutants ΔMnn4 (with no mannosyl-phosphorylation) and ΔMnn2 (linear N-glycosylation backbone), and a commercial enological strain. MPs affected tannin-BSA interactions by delaying aggregation kinetics.

Focus on the relationships between the cell wall composition in the extraction of anthocyanins and tannins from grape berries.

Concentrations of anthocyanins and tannins after extraction from berries in wines and from skin macerations in model solutions have been studied for two grape varieties, two maturation levels and two vintages berries. Characterization of the cell wall polysaccharides has also been performed, the classical method based on the analysis of the neutral sugars after depolymerization being completed by a comprehensive microarray polymer profiling (CoMPP). Extraction was lower in model solutions than in wines, with the same ranking: non acylated anthocyanins> tannins > p-coumaroylated anthocyanins.

The Effects of Grape Polysaccharides Extracted from Grape By-Products on the Chemical Composition and Sensory Characteristics of White Wines.

There is an increasing interest in the valorization of wine waste by-products. Grape pomace/marc can be an important source of polyphenols but also of polysaccharides (PSs). Therefore, the aim of this work was to extract PSs from grape pomace and musts and incorporate them into wines to improve their quality and valorize these residues.

Characterization of polysaccharide extracts recovered from different grape and winemaking products.

One of the most important challenges of the oenological industry is the recovery and valorization of valuable compounds from grapes and grape by-products. Recent studies have focused on the obtention of phenolic compounds, but little attention has been paid to the extraction of grape polysaccharides, which could have a great potential as oenological products but also for their benefits to human health. This study aimed to recover polysaccharides from different grape and winemaking products and provide information about its composition.

Structural characteristics of Saccharomyces cerevisiae mannoproteins: Impact of their polysaccharide part.

While they have many properties of interest in enology, the structure-function relationships of mannoproteins and the part played by their polysaccharide moiety are not yet well understood. Mannoproteins (MP) extracted with β-glucanase from a laboratory yeast strain (WT), two of its mutants (Mnn2 with unbranched N-glycosylated chains and Mnn4 without mannosyl-phosphorylation), and an enological strain (Com) were purified and thoroughly characterized. The protein moiety of the four MPs had the same amino acid composition.

Impact of the variety on the adsorption of anthocyanins and tannins on grape flesh cell walls.

Background: During winemaking, after extraction from the skins, anthocyanins and tannins adsorb onto the pulp flesh cell walls. The present study aimed to quantify the amounts adsorbed and their impact on wine composition, the impact of variety and ethanol on adsorption, and whether the presence of anthocyanins plays a role and impacts tannin adsorption.

Results: Anthocyanin and tannin fractions obtained by mimicking winemaking conditions were mixed with fresh flesh cell walls of two varieties: Carignan and Grenache.

Acacia gums new fractions and sparkling base wines: How their biochemical and structural properties impact foamability?

Foam is the first attribute observed when sparkling wine is served. Bentonite is essentially used to flocculate particles in sparkling base wines but can impair their foamability. Gums from Acacia senegal and Acacia seyal improved the foamability of different bentonite-treated base wines.

Impact of grape variety, berry maturity and size on the extractability of skin polyphenols during model wine-like maceration experiments.

Background: Skin cell walls modulate anthocyanin and tannin extraction from grape skins. However, relationships between the composition of alcohol-insoluble cell wall solids (AIS) and extraction are still unclear. Our objectives were to characterize the impact of variety, berry size and ripeness on skin AIS composition (polysaccharides, proteins) and polyphenol extraction during maceration.

Recent advances in the knowledge of wine oligosaccharides.

Oligosaccharides are carbohydrates with a low polymerization degree containing between three and fifteen monosaccharide residues covalently linked through glycosidic bonds. Oligosaccharides are related to plant defense responses and possess beneficial attributes for human health. Research has focused in wine oligosaccharides only in the last decade.

+ Displays Variable Susceptibility to Chitosan Treatment in Wine.

is the main spoilage microbial agent in red wines. The use of fungal chitosan has been authorized since 2009 as a curative treatment to eliminate this yeast in conventional wines and in 2018 in organic wines. As this species is known to exhibit great genetic and phenotypic diversity, we examined whether all the strains responded the same way to chitosan treatment.

Impact of Contamination on the Characteristics and Foamability of Yeast Macromolecules Released during the Alcoholic Fermentation of a Model Grape Juice.

is a fungal pathogen responsible for the decrease in foamability of sparkling wines. The proteolysis of must proteins originating from botrytized grapes is well known, but far less information is available concerning the effect of grape juice contamination by . The impact from on the biochemical and physico-chemical characteristics of proteins released from during alcoholic fermentation remains elusive.

Improvement of the foamability of sparkling base wines by the addition of Acacia gums.

In sparkling wine, foam characteristics are one of the major attributes. The foam quality depends on wine components. Bentonite is added to the base wine to facilitate the riddling process, but causes a loss of foamability.

Inhibition Mechanisms of Wine Polysaccharides on Salivary Protein Precipitation.

In this work, high-performance liquid chromatography, fluorescence quenching, nephelometry, and sodium dodecyl sulfate polyacrylamide gel electrophoresis were used to study the effect of polysaccharides naturally present in wine [rhamnogalacturonan II (RG II) and arabinogalactan proteins (AGPs)] on the interaction between salivary proteins (SP) together present in saliva and tannins (punicalagin (PNG) and procyanidin B2). In general, the RG II fraction was more efficient to inhibit SP precipitation by tannins, especially for acidic proline-rich proteins (aPRPs) and statherin/P-B peptide, than AGPs. The RG II fraction can act mainly by a competition mechanism in which polysaccharides compete by tannin binding.

The impact of distillation process on the chemical composition and potential prebiotic activity of different oligosaccharidic fractions extracted from grape seeds.

The study was designed to evaluate how the distillation process is able to affect the composition and bioactivity of oligosaccharides contained in the grape seeds. Different oligosaccharidic fractions have been extracted both before and after grape pomace distillation in order to valorize this by-product. A multistep solid-phase extraction approach (C-18 and carbograph cartridges) has been applied to purify and fractionate the oligosaccharidic compounds.

Preharvest Application of Elicitors to Monastrell Grapes: Impact on Wine Polysaccharide and Oligosaccharide Composition.

This work studied the effect of preharvest application in Monastrell grapes of four different elicitors [methyl jasmonate (MeJ), benzothiadiazole (BTH), chitosan from fungi (CHSf), and chitosan from seafood (CHSs)] on wine polysaccharide and oligosaccharide fractions. The polysaccharide and oligosaccharide fractions were isolated and characterized. Neutral monosaccharides were released after hydrolysis of polysaccharides and quantified by gas chromatography (GC).

The role of wine polysaccharides on salivary protein-tannin interaction: A molecular approach.

Polysaccharides are described to inhibit aggregation between food polyphenols and salivary proteins (SP) and may hence lead to astringency modulation. In this work, the effect of two wine polysaccharides (arabinogalactan proteins-AGPs and rhamnogalacturonan II- RGII) on SP-polyphenol interaction was evaluated. In general, both polysaccharides were effective to inhibit or reduce SP-polyphenol interaction and aggregation.

Polysaccharides and Oligosaccharides Produced on Malvar Wines Elaborated with Torulaspora delbrueckii CLI 918 and Saccharomyces cerevisiae CLI 889 Native Yeasts from D.O. "Vinos de Madrid".

Polysaccharides and oligosaccharides released into Malvar white wines elaborated through pure, mixed, and sequential cultures with Torulaspora delbrueckii CLI 918 and Saccharomyces cerevisiae CLI 889 native yeasts from D.O. "Vinos de Madrid" were studied.

Polysaccharides, oligosaccharides and nitrogenous compounds change during the ageing of Tempranillo and Verdejo sparkling wines.

Background: Verdejo and Tempranillo are traditional varieties for producing still wines; however, they could provide an alternative for the manufacturing of sparkling wines. Sparkling wines were elaborated by the traditional method, followed by ageing on lees for 9 months. A study on the changes that take place in polysaccharides, oligosaccharides and nitrogenous compounds during the ageing on lees of Tempranillo and Verdejo sparkling wines has been undertaken.

Effect of grape juice press fractioning on polysaccharide and oligosaccharide compositions of Pinot meunier and Chardonnay Champagne base wines.

Press fractioning is an important step in the production of sparkling base wines to segregate the grape juices with different qualities. Grape juice fractions were collected during the pressing cycle at industrial and laboratory scales. The Pinot meunier and Chardonnay Champagne base wines obtained from the free-run juice and the squeezed juices exhibited strong differences from the beginning to the last step of pressing cycle for numerous enological parameters.

The composition of cell walls from grape skin in Vitis vinifera intraspecific hybrids.

Background: Monastrell is a red grape cultivar adapted to the dry environmental conditions of Murcia, SE Spain. Its berries seem to be characterized by a rigid cell wall structure, which could make difficult the winemaking process. Cabernet Sauvignon cultivar is used to complement Monastrell wines in this region owing to its high phenolic content with high extractability.

Influence of Grape Maturity on Complex Carbohydrate Composition of Red Sparkling Wines.

This paper studied how grape maturity affected complex carbohydrate composition during red sparkling wine making and wine aging. Grape ripening stage (premature and mature grapes) showed a significant impact on the content, composition, and evolution of polysaccharides and oligosaccharides of sparkling wines. Polysaccharides rich in arabinose and galactose, mannoproteins, rhamnogalacturonans II, and oligosaccharides in base wines increased with maturity.

Protein/polysaccharide interactions and their impact on haze formation in white wines.

Proteins in white wines may aggregate and form hazes at room temperature. This was previously shown to be related to pH-induced conformational changes and to occur for pH <3.5.