The use of non-Saccharomyces in wine production has increased steadily since the commercial introduction of the first non-Saccharomyces strains produced as dry active yeasts at the beginning of the ...century by CHR Hansen and Lallemand (2004–2007) ...
Non-Saccharomyces yeast species are currently a biotechnology trend in enology and broadly used to improve the sensory profile of wines because they affect aroma, color, and mouthfeel. They have ...become a powerful biotool to modulate the influence of global warming on grape varieties, helping to maintain the acidity, decrease the alcoholic degree, stabilize wine color, and increase freshness. In cool climates, some non-Saccharomyces can promote demalication or color stability by the formation of stable derived pigments. Additionally, non-Saccharomyces yeasts open new possibilities in biocontrol for removing spoilage yeast and bacteria or molds that can produce and release mycotoxins, and therefore, can help in reducing SO2 levels. The promising species Hanseniaspora vineae is analyzed in depth in this Special Issue in two articles, one concerning the glycolytic and fermentative metabolisms and its positive role and sensory impact by the production of aromatic esters and lysis products during fermentation are also assessed.
Beverage processing is open to new technologies; among them, nonthermal physical technologies such as discontinuous hydrostatic pressure (HHP), ultrahigh-pressure homogenization (UHPH), pulsed ...electric field (PEF), ultrasound (US), atmospheric pressure cold plasma (APCP), or pulsed light (PL) are growing increasingly in the food industry ...
The use of non-Saccharomyces yeasts in enology has increased since the beginning of the current century because of the potential improvements they can produce in wine sensory quality ...
Off-flavors produced by undesirable microbial spoilage are a major concern in wineries, as they affect wine quality. This situation is worse in warm areas affected by global warming because of the ...resulting higher pHs in wines. Natural biotechnologies can aid in effectively controlling these processes, while reducing the use of chemical preservatives such as SO2. Bioacidification reduces the development of spoilage yeasts and bacteria, but also increases the amount of molecular SO2, which allows for lower total levels. The use of non-Saccharomyces yeasts, such as Lachancea thermotolerans, results in effective acidification through the production of lactic acid from sugars. Furthermore, high lactic acid contents (>4 g/L) inhibit lactic acid bacteria and have some effect on Brettanomyces. Additionally, the use of yeasts with hydroxycinnamate decarboxylase (HCDC) activity can be useful to promote the fermentative formation of stable vinylphenolic pyranoanthocyanins, reducing the amount of ethylphenol precursors. This biotechnology increases the amount of stable pigments and simultaneously prevents the formation of high contents of ethylphenols, even when the wine is contaminated by Brettanomyces.
Ultra-high pressure homogenization (UHPH) is a high pressure technique in which a fluid is pressurized by pumping at higher than 200 MPa and instantaneously depressurized at atmospheric pressure ...across a special valve. The full process takes <0.2 s and the in-valve time is <0.02 s. In the valve, extremely intense impacts and shear forces produce the nanofragmentation of biological tissue at a range of 100–300 nm. The antimicrobial effect is highly effective, reaching easily inactivation levels higher than 6-log cycles even at low in-valve temperatures. At in-valve temperatures of 140–150°C (0.02 s) the destruction of thermoresistant spores is possible. Even when the temperature in-valve can be elevated (70–150°C), it can be considered a gentle technology because of the tremendously short processing time. It is easy to get outlet temperatures after valve of 20–25°C by the expansion and assisted by heat exchangers. Thermal markers as hydroxymethylfurfural (HMF) are not formed, nor are deleterious effects observed in sensitive compounds as terpenes or anthocyanins, probably because of the low effect in covalent bonds of small molecules of the high-pressure techniques compared with thermal technologies. Additionally, intense inactivation of oxidative enzymes is observed, therefore protecting the sensory and nutritional quality of fruit juices and avoiding or reducing the use of antioxidants as sulphites. UHPH can be consider a powerful and highly effective continuous and sterilizing technology without thermal repercussions, able to keep fresh juices with most of their initial sensory and nutritional quality and allowing high-quality and natural fermented derivatives as wine.
New Advances in Saccharomyces is a book for yeast researchers that provides a better understanding of yeast metabolism, genetics, and metabolomics applied to the fermentation of alcoholic beverages ...such as wine and beer. The book is structured in three parts and twelve chapters with a significant focus on wine biotechnology. It includes numerous figures and tables with many practical data illustrating the contents and applications. This book is designed to help researchers and scientists develop or improve applications and new processes in fermentation industries for the production of beverages.
In the current situation, wine areas are affected by several problems in a context of global warming: asymmetric maturities, pH increasing, high alcohol degree and flat wines with low freshness and ...poor aroma profile. The use of emerging biotechnologies allows to control or manage such problems. Emerging non-
Saccharomyces
as
Lachancea thermotolerans
are very useful for controlling pH by the formation of stable lactic acid from sugars with a slight concomitant alcohol reduction. Lower pH improves freshness increasing simultaneously microbiological stability. The use of
Hanseniaspora
spp. (specially
H. vineae
and
H. opuntiae
) or
Metschnikowia pulcherrima
promotes a better aroma complexity and improves wine sensory profile by the expression of a more complex metabolic pattern and the release of extracellular enzymes. Some of them are also compatible or synergic with the acidification by
L. thermotolerans
, and
M. pulcherrima
is an interesting biotool for reductive winemaking and bioprotection. The use of bioprotection is a powerful tool in this context, allowing oxidation control by oxygen depletion, the inhibition of some wild microorganisms, improving the implantation of some starters and limiting SO
2
. This can be complemented with the use of reductive yeast derivatives with high contents of reducing peptides and relevant compounds such as glutathione that also are interesting to reduce SO
2
. Finally, the use of emerging non-thermal technologies as Ultra High-Pressure Homogenization (UHPH) and Pulsed Light (PL) increases wine stability by microbial control and inactivation of oxidative enzymes, improving the implantation of emerging non-
Saccharomyces
and lowering SO
2
additions.
•Elimination of vegetative cells of yeast, molds and bacteria by UHPH in must.•Strong inactivation of oxidative enzymes: PPO.•Absence of thermal degradation markers. No detection of HMF.•Higher ...antioxidant activity in UHPH processed must.•UHPH is a powerful tool to reduce SO2 in white wines.
The use of UHPH sterilization in the absence of SO2 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. After UHPH processing, no microorganisms were detected in 1 mL. UHPH musts remain without fermentative activity for more than 60 days. Concentrations of the thermal markers indicated the absence of thermal damage in the UHPH-treated musts, since 5-hydroxymethylfurfural was not detected. In addition, the must treated by UHPH keeps terpene concentrations similar to those of the untreated controls. A strong inactivation of the oxidative enzymes was observed, with no browning at room temperature for more than 3 days. The antioxidant value of the UHPH-treated must was 156% higher than the control.
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 fermentations in which
has been co-inoculated with
,
, or
, and the fermentation process is subsequently completed with sequential inoculation of
. For this purpose, different cell culture media and instruments were used such as infrared spectroscopy, enzymatic autoanalyzer, chromatograph coupled with a flame ionization detector, spectrophotometric analysis, among others. The behavior of these yeasts was evaluated alone and in co-inoculation, always finishing the fermentation with sequential inoculation of
, at a stable temperature of 16°C and with a low level of sulfites (25 mg/L) in white must. Significant results were obtained in terms of biocompatibility using population counts (CFU/ml) in differential plating media that permitted monitoring. Quantification of the five species was studied. Concerning acidification by
in co-inoculations, we showed some metabolic interactions, such as the inhibition of acidification when
/
were used, generating just over 0.13 g/L of lactic acid and, conversely, a synergistic effect when
/
were used, achieving 3.2 g/L of lactic acid and a reduction in pH of up to 0.33. A diminution in alcohol content higher than 0.6% v/v was observed in co-inoculation with the
/
yeasts, with total sugar consumption and very slow completion of fermentation in the inoculations with
and
. The aromatic composition of the wines obtained was analyzed and a sensory evaluation conducted, and it was found that both
and co-inoculations retained more aromatic esters over time and had a lower evolution toward the yellow tones typical of oxidation and that the best sensory evaluation was that of the Lt + Mp co-inoculation.
and co-inoculations produced wines with low levels of volatile acidity (<0.4 g/L). This work shows that good consortia strategies with binary and ternary fermentations of yeast strains can be a powerful bio-tool for producing more complex wines.
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