Iris Loira

• Doctor of Engineering
• Professor (Assistant) at Universidad Politécnica de Madrid

This chapter explores the growing field of emerging nonthermal technologies and biotechnologies focusing on how they can be used in combination with antimicrobial packaging to extend the shelf life of beverages while preserving their nutritional and sensory quality. High pressure processing (HPP), Ultra-high pressure homogenization (UHPH), pulsed e...

Ultra High Pressure Homogenization (UHPH) consists of continuous pumping of must at pressures above 200 MPa, usually 300 MPa, and its subsequent instantaneous depressurization to atmospheric pressure after passing through a special valve. In the valve, the intense impact forces and shear stresses, together with the temperature, lead to the death of...

Yeast selection for the wine industry in Spain started in 1950 for the understanding of the microbial ecology, and for the selection of optimal strains to improve the performance of alcoholic fermentation and the overall wine quality. This process has been strongly developed over the last 30 years, firstly on Saccharomyces cerevisiae, and, lately,...

Hanseniaspora vineae is an apiculate yeast that can be used for the production of interesting commercial wines, due to its contribution of fermentative volatiles. This paper presents a detailed comparative study of the use of H. vineae, compared to pure fermentations of S. cerevisiae in Tempranillo and Albillo rosé wines. Fermentations were carried...

Canopy management practices in vineyards, such as sprawling systems and shoot trimming, can change the accumulation of metabolites in grapes. The use of elicitors of biological origin on grapevines of Vitis vinifera red grape varieties may also modulate the chemical composition of the berries. These modifications are often observed in the accumulat...

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...

Aging on lees (AOL) is a powerful technique to protect varietal aroma and color. Simultaneously, helps to soften tannins and increase and improve wine body and structure. AOL is complementary to barrel aging modulating the wood impact and protecting wine from oxidative conditions. The main drawback is that the yeast autolysis developed during AOL i...

Hanseniaspora vineae is a non-Saccharomyces 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 (Vitis vinifera, L), during vinification is a useful biotechnology to improve sensory complexity. Fermentation in steel barrels using Hanseniaspora vi...

The cover image for the full Vol6 of Fermentation MDPI is the graphical abstract of our article 'Impact of Hanseniaspora Vineae in Alcoholic Fermentation and Ageing on Lees of High-Quality White Wine' July 2020Fermentation 6(3):66 DOI: 10.3390/fermentation6030066

In recent times, nanotechnology is expanding its field of application to very diverse areas. One of the most outstanding uses of nanotechnology in oenology is the incorporation of nanoparticles to sensors of different nature (electrochemical, biological, amperometric or fluorimetric) to improve the analysis of wine components such as polyphenols, o...

Open Access available at https://doi.org/10.3390/beverages6030045 ------------------------------------------------------------- Pulsed light is an emerging non-thermal technology viable for foodstuff sanitation. The sanitation is produced through the use of high energy pulses during ultra-short periods of time (ns to µs). The pulsed light induces i...

Hanseniaspora vineae is an apiculate yeast that plays a significant role at the beginning of fermentation, and it has been studied for its application in the improvement of the aromatic profile of commercial wines. This work evaluates the use of H. vineae in alcoholic fermentation compared to Saccharomyces cerevisiae and in ageing on the lees proce...

http://www.acenologia.com/cienciaytecnologia/fml_fumarico_quitosano_cienc176_0620.htm --------------- La fermentación maloláctica (FML) se desarrolla inoculada o no de forma habitual en vinos tintos; sin embargo, es más infrecuente en vinos blancos y rosados. Aunque en ocasiones sucede, incluso de forma indeseada, restando acidez y por tanto fresc...

Pulsed electric fields (PEFs) are an emerging cold technology capable of reducing wild yeast in either musts or crushed grapes, facilitating the implantation of starters while increasing the extraction of both phenols and aroma compounds. PEFs with an intensity of 20 kV/cm, 150 pulses, and 3 μs were applied continuously to the must of Vitis vinifer...

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. Additionally, a high pH makes wines more chemically and microbiologically unstable, requiring a higher sulphite content for preservation. Some strains of Lachancea ther...

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 300MPa (inlet temperature: 23-25°C). The initial microbial load of the settled must was 4-log CFU/mL for both yeast and moul...

This chapter reviews the main non-thermal technologies with application in enology and their impact in: the extraction of phenolic compounds from grapes, the elimination of indigenous microorganisms, and the subsequent effect in SO2 reduction. The technologies are physical processes with null or low repercussion in temperature and therefore gentle...

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 denomin...

Anthocyanins and volatile aromas may contribute to the identity of a wine varietal. Various parameters such as terroir (including vineyard altitude), viticultural management, vinification techniques and ageing conditions can influence the physiochemical pathways of the compounds. This work evaluated the anthocyanins and volatile compounds of two mo...

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 te...

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). Recent studies w...

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 th...

One of the problems related to the increase in average temperatures in the wine-growing regions is the lower accumulation of organic acids in the berries. Wine freshness depends to a great extent on its acidity. Herein, the effectiveness of fumaric acid to inhibit malolactic fermentation or to stop it once initiated is evaluated in order to preserv...

https://doi.org/10.1016/B978-0-12-816678-9.00015-1 ----------------- Abstract In the last few years, non-Saccharomyces yeasts have been gaining increasing importance in the field of oenology because of its specific contribution to the chemical composition of the wine when they are used alone or in combination with other yeast genera. Moreover, wine...

Available from: https://www.intechopen.com/books/advances-in-grape-and-wine-biotechnology Advances in Grape and Wine Biotechnology is a collection of fifteen chapters that addresses different issues related to the technological and biotechnological management of vineyards and winemaking. It focuses on recent advances in the field of viticulture wit...

Metschnikowia pulcherrima (Mp) is a ubiquitous yeast that frequently appears in spontaneous fermentations. The current interest in Mp is supported by the expression of many extracellular activities, some of which enhance the release of varietal aromatic compounds. The low fermentative power of Mp makes necessary the sequential or mixed use with Sac...

Available from: https://www.intechopen.com/online-first/strategies-to-improve-the-freshness-in-wines-from-warm-areas Abstract Trends in wine consumption are continuously changing. The latest in style is fresh wine with moderate alcohol content, high acidity, and primary aromas reminiscent of grapes, whereas certain fermentative volatiles may also...

The use of non-Saccharomyces yeasts means a great source of biodiversity for the production of differentiated beer products. With this objective, five species of different genera have been selected in order to evaluate their influence on beer quality. Two different experiments were carried out with four non-Saccharomyces strains (Schizosaccharomyce...

The ageing on lees is a technique particularly interesting in the production of red wines due to the possibility of enhancing some of their sensory characteristics. Different authors have researched the ultrasound assistance to accelerate this ageing process in wines. The present work evaluated the modification that both fractions, polyphenolic and...

In warm regions, a typical problem is to reach high pH in must together with excessive sugar concentration, this problem is being increased by climatic change. In most of the wine regions of the south centre of Spain, it is easy to find red musts with pH values in the range 3.8–4.0 that after fermentation frequently exceed pH 4. This low acidity is...

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...

Vermouth is a wine derivative produced from a base wine, usually white, fortified with wine spirit, colored by caramel with residual sugar level frequently about or higher than 100 g/L and aromatized with several dried herbs and extracts to get a typical bitter taste. Probably, it is the wine-derived aperitif most consumed worldwide. The present ch...

Milk represents the archetypal probiotic food, which nature has provided to human beings. With an increase in human life expectancy, and the exponential growth of health-care costs, strategies are being continuously proposed to tackle new challenges through the development of effective, cheap, and accessible remedies such as probiotic and symbiotic...

Ultra-High Pressure Homogenization Sterilization (UHPHS) allows the sterilization of fluid foods at low temperatures or even in refrigeration. UHPHS is a continuous technique that allows to process 10,000 L/h with a single pump working at 300 MPa with an imbalance of 1 MPa (Ypsicon EP2409583). During the process, fluid temperature increases less th...

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 stabl...

The release of high molecular weight polysaccharides during the ageing on lees technique results in the increase of the red wine structure [1]. In addition, this technique provides an improvement in the quality and aromatic intensity of wines [2]. The main objective of this study is to accelerate the ageing on lees technique by the addition of prev...

Ultra-High Pressure Homogenization (UHPH) is a fast and efficient technique that can sterilize fluid foods at low temperatures or even under cooling conditions. A white must (Vitis vinifera L.) was processed at 300 MPa (inlet temperature 20 °C, in-valve temperature 98 °C, outlet temperature 25 °C, and time in valve 0.02 s) and their performance was...

El uso de levaduras no-Saccharomyces cada vez está más extendido en enología por las posibilidades tecnológicas que ofrece y la mejora de la calidad de los vinos. En climas cálidos uno de los principales problemas es el control del pH, dificultando la estabilidad de los vinos y haciéndolos propensos a alteraciones microbiológicas. Lachancea thermot...

There are numerous yeast species related to wine making, particularly non-Saccharomyces, that deserve special attention due to the great potential they have when it comes to making certain changes in the composition of the wine. Among them, Schizosaccharomyces pombe stands out for its particular metabolism that gives it certain abilities such as re...

The genus Zygosaccharomyces is generally associated to wine spoilage in the winemaking industry, since a contamination with strains of this species may produce re-fermentation and CO2 production in sweet wines. At the same time, this capacity might be useful for sparkling wines production, since this species may grow under restrictive conditions, s...

There are numerous yeast species related to wine making, particularly non-Saccharomyces, that deserve special attention due to the great potential they have when it comes to making certain changes in the composition of the wine. Among them, Schizosaccharomyces pombe stands out for its particular metabolism that gives it certain abilities such as re...

Lachancea (kluyveromyces) thermotolerans is a ubiquitous yeast that can be naturally found in grapes but also in other habitats as soil, insects and plants, extensively distributed around the world. In a 3-day culture, it shows spherical to ellipsoidal morphology appearing in single, paired cells or short clusters. It is a teleomorph yeast with 1–4...

The usage of alternative non-Saccharomyces yeasts might provide desirable characteristics to white and red sparkling wines. In this study, second fermentation in the bottle was carried out by Saccharomyces cerevisiae as control and two non-Saccharomyces species: Saccharomycodes ludwigii and Schizosaccharomyces pombe. The second fermentations of whi...

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. Different authors have studied the application of new techniques to accelerate...

The use of non-Saccharomyces yeasts can provide advantages in winemaking such as: a reduction of ethanol content, the synthesis of certain metabolites that are important for color stability or a good yield in the production of certain volatile compounds (ethyl lactate, 2,3-butanediol, 2-phenylethyl acetate). The main objective was general evaluatio...

Yeast - Industrial Applications is a book that covers applications and utilities of yeasts in food, chemical, energy, and environmental industries collected in 12 chapters. The use of yeasts in the production of metabolites, enzymatic applications, fermented foods, microorganism controls, bioethanol production, and bioremediation of contaminated en...

Vitis vinifera (variety Tempranillo) grapes were processed by pulsed light (PL) at several treatment conditions before fermentation. The effect on grape external structure, wild microbial populations, phenol extraction and wine composition was monitored. PL treatments decreased significantly microbial loads in grapes. After treatment, the grapes we...

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, Procyanid...

Background Nowadays emerging technologies for food preservation is a topic of increasing importance because of the high efficiency of these techniques controlling pathogenic or spoilage microorganisms in foods. Most of these technologies also work at low temperature (cold pasteurization processes) improving nutritional or sensory quality. Scope and...

In the past decade, use of nanotechnology has risen significantly in the field of enology. Here, some nanotechnology applications are discussed and their convenience for winemaking is evaluated in order to improve wine quality and safety, as well as to facilitate wine analysis. One of the most studied opportunities for nanoparticles in enology is t...

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 inves...

Vitisins are usually analysed by HPLC‐DAD separation and quantitation, using an external standard of malvidin‐3‐O‐glucoside. Traditional LC separations are done in C18 reverse phase columns and the elution is produced with a gradient of water and methanol or water and acetonitrile. To keep anthocyanins in the cationic form (pyrilium form), the use...

Vitis vinifera (variety Tempranillo) grapes were pressurized at 400 MPa by high hydrostatic pressure for 10 min and the effect on wild microbial populations, phenol extraction and wine composition was monitored. After treatment, the grapes were inoculated and fermented with Saccharomyces cerevisiae and several non-Saccharomyces yeasts: Schizosaccha...

Aims: To assess the influence of non-Saccharomyces yeasts on the pyranoanthocyanins and polymeric pigments formation after the addition of (+)-catechin and procyanidin B2 to fresh red grape must. Methods and results: The fermentation of red grape musts was done with non-Saccharomyces yeasts either alone or in sequential fermentations with the Sa...

Over time, winemaking techniques have evolved to be a perfect blend of science, culture and art. One such practice is the ‘sur lie’ method, which can be literally translated from French as ‘on lees’. Ageing on lees has long been considered to benefit overall wine quality by enhancing body, mouthfeel as well as sensorial complexity and color stabili...

Schizosaccharomyces was initially considered as a spoilage yeast because of the production of undesirable metabolites such as acetic acid, hydrogen sulfide, or acetaldehyde, but it currently seems to be of great value in enology. Nevertheless, Schizosaccharomyces can reduce all of the malic acid in must, leading to malolactic fermentation. Malolact...

Over recent years, ageing on lees has acquired a great distinction in winemaking as an interesting technique for improving wine quality. The aim of the present work was to evaluate the effectiveness of two novel processing techniques, ultrasounds and microwaves (both combined with stirring and abrasion treatments), in order to accelerate the autoly...

Vermouth is an aromatized and fortified wine flavored with botanicals. In red vermouth color is obtained by dyeing with caramel. Color can be improved by using natural grape anthocyanins. Natural anthocyanins give to this product a better color and at the same time increase the contents of flavonoid pigments with positive repercussion on health. Th...

Sonication is an emerging non-thermal technology useful to disrupt cell wall and increase polysaccharides release when applied to red wines aged on lees. At the same time, ultrasound treatment may cause changes in the composition of the wine, both in the phenolic and aromatic compounds. In this work, we evaluated the influence of ultrasounds treatm...

The color, together with the aroma and the body, is one of the most important quality parameters for red wines. Pyranoanthocyanins, stable pigments found in wines, are produced through condensation of anthocyanins like malvidin-3-O-glucoside with yeast metabolites such as pyruvate and acetaldehyde; with vinyl phenolic compounds from hydroxycinnamic...

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...

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...

Two novel techniques: use of non-Saccharomyces strains coupled with ultrasound treatment were tested to see their efficiency for accelerating ageing on lees. The combined effects of the techniques were tested to see their impacts on the polysaccharide release and on the organoleptic properties of red wine. Release of polysaccharides was analysed by...

Vitis vinifera L. (variety Tempranillo) grapes were subjected to electron beam irradiation at nominal doses of 0.5, 1 and 10 kGy, and the effect on microbial populations, phenol extraction and wine quality was examined. No external modifications of fruit shape or colour were observed with any of the doses tested. The 1 kGy dose reduced initial must...

Vitis vinifera (variety Tempranillo) grapes were subjected to high hydrostatic pressure (HHP) treatments of 200, 400 and 550 MPa for 10 min, and its effect on microbial populations, phenol extraction and wine quality was examined. At ≥400 MPa, the wild yeast population was strongly reduced from 104 to Anthocyanin extraction was also increased, prod...

Torulaspora delbrueckii is a non-Saccharomyces yeast with interesting metabolic and physiological properties of potential use in oenology. This work examines the fermentative behaviour of five strains of T. delbrueckii in sequential fermentations with Saccharomyces cerevisiae, analysing the formation of aromatic compounds, polyalcohols and pigments...

Bacterial cellulose (BC) as a never-dried biopolymer synthesized in abundance by Gluconacetobacter xylinus is in a pure form which requires no intensive processing to remove unwanted impurities and contaminants such as lignin, pectin and hemicellulose. In contrast to plant cellulose, BC, with several remarkable physical properties, can be grown to...

The present review describes a number of metabolic inhibitors capable of redirecting the glycolytic pathway in winemaking yeasts of the species Saccharomyces cerevisiae, leading to an increase in yeast biomass production and the excretion of secondary metabolites alongside a desired reduction in wine alcohol content. The main application of these i...

Ageing on lees involves ageing the wine in contact with yeast cells after fermentation. If combined with the addition of oak chips, it can soften the wood flavour and increase the aromatic complexity of wine. The aim of the present work is to optimise both ageing techniques through selection of an adequate Saccharomyces cerevisiae strain. The study...

The selection of glycolytically inefficient yeasts is of interest for producing wines with less ethanol, especially when they can also improve their sensorial properties. The selection criteria used in the present study included low fermentative power and high production of secondary metabolites with a positive sensorial impact on red wine. Yeast s...

Schizosaccharomyces pombe is a non-Saccharomyces yeast strain that can ferment grape musts with high sugar contents - but it also has other metabolic and physiological properties that render it of great interest to wine biotechnologists. This work compares the production of pyranoanthocyanins by S. pombe, Saccharomyces cerevisiae and Saccharomyces...