Jose Maria Heras

Lallemand Inc. · Research and Development

Sulfur dioxide is the most used additive today for preventing browning in grape musts and wines. However, since wine consumers are increasingly interested in healthier wines, the wine industry is keen to reduce its use. Some promising alternatives to sulfur dioxide have been proposed in recent years, including glutathione, both pure and in the form...

This communication studies some possible strategies to reduce or even to replace sulfur dioxide in winemaking. Specifically, the aim of this work was to study the protective effect against oxidation of a commercial inactivated dry yeast (IDY) with very high level of glutathione, and of a selected non-Saccharomyces yeast, Metschnikowia pulcherrima s...

Sulfur dioxide is the most used additive today for preventing browning in grape musts and wines. However, since wine consumers are increasingly interested in healthier wines, the wine industry is keen to reduce its use. Some promising alternatives to sulfur dioxide have been proposed in recent years, including glutathione, both pure and in the form...

In the current scenario of climatic warming, the over-ripening of grapes increases the sugar content, producing alcoholic wines, with low acidity, high pH and low freshness. Additionally, a high pH makes wines more chemically and microbiologically unstable, requiring a higher sulphite content for preservation. Some strains of L. thermotolerans (Lt)...

The use of non-Saccharomyces yeast in the winemaking industry and even more their co-inoculations to maximize their growth and to express phenotypic characteristic is gaining more and more relevance. This study aimed to shed light on the biocompatibilities between Lachancea thermotolerans and Hanseniaspora spp., using different types of nutrients a...

Non‐wine yeasts could enhance the aroma and organoleptic profile of wines. However, compared to wine strains, they have specific intolerances to winemaking conditions. To solve this problem, we generated intra‐ and interspecific hybrids using a non‐GMO technique (rare‐mating) in which non‐wine strains of S. uvarum, S. kudriavzevii and S. cerevisiae...

Interest in the use of non-conventional yeasts in wine fermentation has been increased in the last years in the wine sector. The main objective of this manuscript was to explore the aromatic diversity produced by wild and non-wine strains of S. cerevisiae, S. eubayanus, S. kudriavzevii, and S. uvarum species in young and bottle-aged Tempranillo win...

Saccharomyces yeasts from different origins and species fermented in a semi-synthetic must containing aroma precursor of cv. Albariño and polyfunctional mercaptans precursors. The resulting wines were subjected to accelerate anoxic aging. Afterward, aroma profiles were analyzed by distinct gas chromatography methodologies. Cryotolerant strains show...

Lachancea thermotolerans is a frequent yeast in the indigenous microbiota of grapes. Its main ability is the metabolization of sugars into lactic acid by using the lactate dehydrogenase enzyme, naturally decreasing wine pH during fermentation and improving wine freshness. The acidity improvement can range between 0.1 and 0.5 pH units in relation to...

This study aimed at determining the changes induced by two S. cerevisiae strains, (IONYS wf™ and Lalvin ICV D254™) on the sensory and chemical aroma profiles of Tempranillo wine, after fermentation and after ageing. The 64 aroma molecules determined were grouped attending to sensory and chemical similarity into 17 aroma vectors. Sensory studies inc...

Climate change is affecting vineyards, resulting in grapes with a low acidity a high pH and sug-ar at harvest time. The most common procedure so far to improve the acidity and reduce the fi-nal pH of wines is to use tartaric acid, but wine can also be acidified microbiologically using Lachancea thermotolerans yeasts, a natural bio-tool that acidifi...

Global warming is causing serious problems, especially, in warm regions, where musts with excess sugars and high pH produce wines with decreased freshness and unstable evolution. This study aimed to determine biocompatibility between yeast species, the capacity for microbiological acidification, and the aromatic profile produced in ternary fermenta...

The aim of the study was to evaluate the oxygen consumption kinetics of some inactivated dry yeasts in comparison with those of sulfur dioxide, ascorbic acid and glutathione. The oxygen consumption rates of three inactivated dry yeasts, sulfur dioxide, ascorbic acid and glutathione at the usual doses in a model wine solution were determined by carr...

Ten different Saccharomyces cerevisiae strains fermented semi-synthetic musts containing a Polyphenolic and Aroma Precursor Fraction (PAF) extracted from Tempranillo grapes. Aroma compounds were studied by Gas Chromatography (GC), GC-Olfactometry and GC-Mass Spectrometry (MS), during fermentation by trapping volatilized aroma, immediately after fer...

A collection of 33 Saccharomyces yeasts were used for wine fermentation with a sole nitrogen source: ammonium and four individual aroma-inducing amino acids. The fermentation performance and chemical wine composition were evaluated. The most valuable nitrogen sources were valine as a fermentation promoter on non-cerevisiae strains, phenylalanine as...

Cocoa pulp fermentation is a consequence of the succession of indigenous yeasts, lactic acid bacteria and acetic acid bacteria that not only produce a diversity of metabolites, but also cause the production of flavour precursors. However, as such spontaneous fermentations are less reproducible and contribute to produce variability, interest in a mi...

Nitrogen requirements by S. cerevisiae during wine fermentation are highly strain-dependent. Different approaches were applied to explore the nitrogen requirements of 28 wine yeast strains. Based on the growth and fermentation behaviour displayed at different nitrogen concentrations, high and low nitrogen-demanding strains were selected and further...

Non-Saccharomyces yeast strains have become increasingly prevalent in the food industry, particularly in winemaking, because of their properties of interest both in biological control and in complexifying flavour profiles in end-products. However, unleashing the full potential of these species would require solid knowledge of their physiology and m...

Open Access at: https://doi.org/10.3390/microorganisms8060830 --------------------------------------------------------------------------------------------------- In the current scenario of climatic warming, the over-ripening of grapes increases the sugar content, producing flat and alcoholic wines with low acidity, high pH and low freshness. Additi...

Malolactic fermentation (MLF) in wine is an important step in the vinification of most red and some white wines, as stands for the biological conversion of l-malic acid into l-lactic acid and carbon dioxide, resulting in a decrease in wine acidity. MLF not only results in a biological deacidification, it can exert a significant impact on the organo...

In European regions of cold climate, S. uvarum can replace S. cerevisiae in wine fermentations performed at low temperatures. S. uvarum is a cryotolerant yeast that produces more glycerol, less acetic acid and exhibits a better aroma profile. However, this species exhibits a poor ethanol tolerance compared with S. cerevisiae. In the present study,...

: This study investigates the effects of simultaneous inoculation of a selected Saccharomyces cerevisiae yeast strain with two different commercial strains of wine bacteria Oenococcus oeni at the beginning of the alcoholic fermentation on the kinetics of malolactic fermentation (MLF), wine chemical composition, and organoleptic characteristics in c...

Wine-related non-Saccharomyces yeasts are becoming more widely used in oenological practice for their ability to confer wine a more complex satisfying aroma, but their metabolism remains unknown. Our study explored the nitrogen utilisation profile of three popular non-Saccharomyces species, Torulaspora delbrueckii, Metschnikowia pulcherrima and Met...

The use of specific inactivated dry yeast preparations is a quick and effective alternative to aging on lees, because they can improve the technological and sensory properties of the wines and eliminate or reduce certain disadvantages that this aging on lees involves. In this work the impact of the application of a specific inactivated dry yeast (P...

Wines from grapes of Cabernet Sauvignon of the AOC Tarragona were elaborated with supplementation or not of two specific inactivated dry yeasts (Optired® and Optimum Red®; Lallemand Inc.) or with an experimental grape-skin extract. All the wines treated were significantly less astringent than the control wine because both inactivated dry yeast and...

Lactobacillus plantarum has been used for deacidifying wines through malolactic fermentation (MLF), and more recently for acidifying them. The species Oenococcus oeni is mainly responsible for MLF in wines at a pH below 3.5. However, the Lactobacillus and Pediococcus species can carry out this reaction in wines at a higher pH. MLF generally begins...

This work studies the influence of two different nitrogen sources added to the must on aromatic series and sensory profile of 'Chardonnay' wines. Volatile compounds were classified into six odorant series and the total intensities for every aromatic series were calculated as sum of the OAV of each one of the compounds assigned to these series. Sens...

In a previous study, we reported that sequential inoculation of Torulaspora delbrueckii (strain TD291) and a specific strain of Saccharomyces cerevisiae during the first fermentation increased the protein concentration and improved the foaming properties of a base wine. Since effervescence and foam of sparkling wines are key quality factors, the in...

Background and Aims Oenococcus oeni is the lactic acid bacteria species that best adapts to harsh wine conditions. This species is currently the main component of the malolactic starter cultures used in winemaking. Other species of lactic acid bacteria, however, such as Lactobacillus, can also conduct the malolactic fermentation, especially in low...

Different sparkling wines were elaborated with a base wine of Macabeo from the AOC Cava using the traditional method with supplementation or not of inactivated dry yeasts of Saccharomyces cerevisiae(OptimumwhiteTM) or Torulaspora delburueckii (TD291). After 9 months, the samples were analyzed and tasted. The supplementation with both IDY (S. cerevi...

Grapes of Tempranillo, Garnacha Tinta and Merlot at very high maturity level were used for red microvinifications using a conventional Saccharomyces cerevisiae strain (Lalvin EC 1118®) and new S. cerevisiae strain generated using adaptive evolution-based strategies (IONYS™ WF). All microvinifications were performed by triplicate and at low (16∘C) a...

Aunque resulte obvio, la efervescencia y la estabilidad de la espuma son los principales factores que condicionan la calidad de los vinos espumosos. Sin duda, otros aspectos como el sabor y el aroma juegan también un papel importante, pero la efervescencia y la persistencia de la espuma son atributos diferenciales en los vinos espumosos y por tanto...

The quality of sparkling wines depends on several factors. Among them, effervescence and foam are probably some of major determinants of the quality of this kind of wines. For that reason, one of the main concerns of sparkling wine industry is find new procedures to improve the foamability and the foam persistence. The foaming properties of sparkli...

Foam stability of sparkling wines is significantly favored by the presence of surface active agents such as proteins and polysaccharides. For that reason, the renowned sparkling wines are aged after the second fermentation in contact with the lees for several months (even years). Thereby wines are enriched in these macromolecules due to yeast autol...

Because of global warming, wines are obtained nowadays with high pH values and low acidity. This results in wines with disturbed flavor and increased susceptibility of microbial spoilage. The aim of this work was the selection of Lactobacillus strains with ability to induce biological acidification in low acidity grape musts to obtain more acidic w...

In a previous study we reported that sequential inoculation of Torulaspora delbrueckii and Saccharomyces cerevisiae during the first fermentation increased the protein concentration and improved the foaming properties of a base wine. Since effervescence and foam of sparkling wines are key quality factors, the interest of this practice for sparkling...

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 w...

The use of mixed inoculation of non-Saccharomyces yeasts and S. cerevisiae in wine fermentations is of increasing interest for quality enhancement and improved complexity of wines. The effect of sequential inoculation of Wickerhamomyces anomalus (formerly Hansenula anomala) with interesting enological properties in terms of secondary metabolite pro...

The behaviour in malolactic fermentation (MLF) of an autochthonous strain of Oenococcus oen4 C22L9, isolated from a winery in Castifia-La Mancha (Spain), and of two other commercial strains of 0. oeni, PN4 and Alpha (Lallemand Inc.), inoculated by direct inoculation (MBR®) and after a short accimatisation phase (1-STEP®), was studied. Strain C22L9...

p style="text-align: justify;"> Aims : Developing, by classical genetic methods, new wine yeast strains showing improved release of mannoproteins during wine fermentation, as well as suitable selection procedures for this purpose. These strains would be useful to improve quality characters associated to wine mannoprotein content. Methods and result...

Ethyl carbamate (EC) is a carcinogenic compound found in fermented food and beverages such as wine. Although its carcinogenic potential in animals is known, information regarding its effects in humans remains insufficient, thus there is increasing interest in its research. EC content is higher in products with high alcohol content and in aged produ...

Los ácidos orgánicos del vino potencian su color, riqueza sensorial y estado higiénico. Una falta de acidez se traduce en falta de brillantez, aromas y estabilidad microbiológica, y da lugar a un aspecto gustativo plano del vino.

Riassunto Un lievito, isolato dal Gruppo di Biotecnologia Enologica all'Università Rovira i Virgili (Tarragona) a partire da mosti provenienti dalla prestigiosa regione del Priorato in Spagna, caratterizzati da elevato tenore di zuccheri e polifenoli e ridotto contenuto d'azoto, è stato testato per alcune vendemmie e si è rivelato capace di mantene...

Introducción Para los enólogos el nitrógeno, que estimula la fermentación llevada a cabo por las levaduras vínicas, es un nutriente esencial para una buena fermentación alcohólica (FA). Durante los últimos 20 años, varios estudios han demostrado que el nitrógeno tiene un efecto positivo sobre el crecimiento y la actividad fermentativa de la levadur...