Improvement of Must Fermentation from Late Harvest cv. Tempranillo Grapes Treated with Pulsed Light.

Pulsed light irradiation is a nonthermal technology currently used for the elimination of pathogens from a diverse range of food products. In the last two decades, the results obtained using PL at laboratory scale are encouraging wine experts to use it in the winemaking industry. PL can reduce native yeast counts significantly, which facilitates the use of starter cultures, reducing SO requirements at the same time.

The Impact of Fermentation and Ageing on Lees on the Terpenic Aromatic Profile of White Wines of the Albillo Variety.

is a non- yeast that has a powerful impact on the sensory profile of wines. Its effect on the aromatic profile of non-aromatic grape varieties, such as Albillo Mayor (, L), during vinification is a useful biotechnology to improve sensory complexity. Fermentation in steel barrels using and sequential inoculation with have been used to study the formation of terpenes and cell lysis in the production of Albillo white wines.

White wine processing by UHPH without SO. Elimination of microbial populations and effect in oxidative enzymes, colloidal stability and sensory quality.

The use of UHPH sterilization in the absence of SO has been used to eliminate wild microorganisms and inactivate oxidative enzymes. A white must of the Muscat of Alexandria grape variety was continuously processed by UHPH at 300 MPa (inlet temperature: 23-25 °C). The initial microbial load of the settled must was 4-log CFU/mL for both yeast and moulds, and slightly lower for bacteria.

Evolution of the Phenolic Fraction and Aromatic Profile of Red Wines Aged in Oak Barrels.

Various changes occur in red wine during aging in oak barrels. Among these, the variation of the polyphenolic fraction and the transfer of aromatic compounds to the wine from oak wood are of great importance. The aim of the present work is to compare the chemical composition of wines aged in different new oak barrels with similar commercial denominations.

Contribution of Non- Yeasts to Wine Freshness. A Review.

Freshness, although it is a concept difficult to define in wines, can be understood as a combination of different circumstances. Organolepticwise, bluish red, floral and fruity, more acidic and full-bodied wines, are perceived as younger and fresher by consumers. In traditional winemaking processes, these attributes are hard to boost if no other technology or biotechnology is involved.

Influence of and non- Yeasts in the Formation of Pyranoanthocyanins and Polymeric Pigments during Red Wine Making.

Yeast are able to modulate many sensory parameters of wines during red must fermentation. The effect on color and on the formation of derived pigments during fermentation has been studied thoroughly since the 90s. Yeast can increase grape anthocyanin's color by acidification by hyperchromic effect (increase of flavylium molecules).

Use of fumaric acid to control pH and inhibit malolactic fermentation in wines.

Fumaric acid is an additive allowed by the Codex Alimentarius and under evaluation by the International Organisation of Vine and Wine (OIV) that can be used for wine acidification but also to inhibit malolactic fermentation (MLF). The use of 300-900 mg/L of fumaric acid can inhibit MLF in red wines decreasing pH by 0.2 units or more depending on the buffer capacity.

Study of the Interaction of Anthocyanins with Phenolic Aldehydes in a Model Wine Solution.

Aldehydes may be present in wines as a result of metabolic processes during wine fermentation or through oxidation and extraction from wood during wine aging in oak barrels. Apart from acetaldehyde, the most abundant aldehyde in wine, other aldehydes such as furfural and more recently vanillin have shown to contribute to the formation of more stable pigments. The copigmentation effect of phenolic molecules, including flavanols and anthocyanins themselves, has been previously evaluated in wine and model solutions, and even the effect of aldehydes related to wine aging has been documented at different pHs and molar ratios.

Sonication of Yeast Biomasses to Improve the Ageing on Lees Technique in Red Wines.

Ageing on Lees (AOL) is a technique to improve the aromatic and gustatory complexity of wine, mainly by improving its body and reducing its astringency. However, the autolytic process is slow, resulting in high production costs. This work evaluated the effect of adding sonicated lees and combining it with oak chips, as a new technique to accelerate the AOL process and improve the aromatic quality of aged red wine.

Effect of on the Formation of Polymeric Pigments during Sequential Fermentation with and .

Anthocyanins in red grape musts may evolve during the winemaking process and wine aging for several different reasons; colour stability and evolution is a complex process that may depend on grape variety, winemaking technology, fermentative yeast selection, co-pigmentation phenomena and polymerization. The condensation of flavanols with anthocyanins may occur either with the flavylium ion or with the hemiacetal formation in order to produce oligomers and polymers. The kinetics of the reaction are enhanced by the presence of metabolic acetaldehyde, promoting the formation of pyranoanthocyanin-type dimers or flavanol-ethyl-anthocyanin structures.

Application of ultrasound to improve lees ageing processes in red wines.

Ageing on lees (AOL) is a technique that increases volatile compounds, promotes colour stability, improves mouthfeel and reduces astringency in red wines. The main drawback is that it is a slow process. Several months are necessary to obtain perceptible effects in wines.

Use of non-Saccharomyces yeasts and oenological tannin in red winemaking: Influence on colour, aroma and sensorial properties of young wines.

Today, many non-Saccharomyces strains have been verified can be positive for the development of wine anthocyanin and aroma in different fermentation scenarios. Moreover, oenological tannins are widely used in wine industry to improve the colour profile and aroma complexity. The aim of this work is to analyze the fermentation characters of non-Saccharomyces strains and investigate the effects of pre-fermentative addition of oenological tannins on the wine components as well as sensory properties.

Formation of polymeric pigments in red wines through sequential fermentation of flavanol-enriched musts with non-Saccharomyces yeasts.

Non-Saccharomyces yeasts may contribute to enrich wine aroma while promoting the formation of stable pigments. Yeast metabolites such as acetaldehyde and pyruvate participate in the formation of stable pigments during fermentation and wine aging. This work evaluated the formation of polymeric pigments in red musts added with (+)-Catechin, ProcyanidinB2 and ProcyanidinC1.

The Effects of Pre-Fermentative Addition of Oenological Tannins on Wine Components and Sensorial Qualities of Red Wine.

Today in the wine industry, oenological tannins are widely used to improve wine quality and prevent oxidation in wine aging. With the development of tannin products, new oenological tannins are developed with many specific functions, such as modifying antioxidant effect, colour stabilization and aroma modifications. The aim of this work is to investigate effects of pre-fermentative addition of oenological tannins on wine colour, anthocyanins, volatile compounds and sensorial properties.

Yeast influence on the formation of stable pigments in red winemaking.

The anthocyanin profile of a wine greatly varies over time depending on many factors. In addition to color modifications due to changes in the chemical composition of wine, there may be some influence of the yeast strain used in fermentation. The main aim of this study is to identify and quantify the different ways in which yeast may influence on wine color and its stability, during red winemaking.

Use of Schizosaccharomyces pombe and Torulaspora delbrueckii strains in mixed and sequential fermentations to improve red wine sensory quality.

One of the main opportunities in the use of non-Saccharomyces yeasts is its great intraspecific variability in relation to the synthesis of secondary products of fermentation. Thus, mixed or sequential fermentation with non-Saccharomyces can increase the synthesis of certain metabolites that are important for colour stability, such as acetaldehyde and pyruvic acid (vitisin precursors) or vinylphenols (vinylphenolic pyranoanthocyanin precursors). Furthermore, the selection and use of non-Saccharomyces yeast strains with good yields in the production of certain volatile compounds (ethyl lactate, 2,3-butanediol, 2-phenylethyl acetate), with limited formation of higher alcohols, is a way to improve the aromatic profile of red wine.

Wood impregnation of yeast lees for winemaking.

This study develops a new method to produce more complex wines by means of an indirect diffusion of wood aromas from yeast cell-walls. An exogenous lyophilized biomass was macerated with an ethanol wood extract solution and subsequently dried. Different times were used for the adsorption of polyphenols and volatile compounds to the yeast cell-walls.

Formation of vinylphenolic pyranoanthocyanins by selected yeasts fermenting red grape musts supplemented with hydroxycinnamic acids.

The aim of this work was to study the formation of vinylphenolic pyroanthocyanin pigments by three strains of Saccharomyces cerevisiae and one strain each of Saccharomyces uvarum and Saccharomyces montuliensis during the fermentation of red grape (Vitis vinifera L. cv. Tempranillo) must containing additional hydroxycinnamic acids (caffeic acid, ferulic acid or p-coumaric acid, 50 mg/l).