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A cryo-macerated must of V. vinifera L. cabernet sauvignon was processed by ultra-high-pressure homogenisation (UHPH) sterilisation without the use of SO2. The UHPH treatment of the must was carried out continuously at a pressure of 300 MPa and reaching a maximum temperature of 77 °C for less than 0.2 s. The colloidal structure of the UHPH must was evaluated by atomic force microscopy (AFM) measuring an average particle size of 457 nm. The initial microbial load was 4-log CFU/mL (yeast), 3-log CFU/mL (bacteria). No yeast and non-sporulating bacteria were detected in 1 mL and 10 mL of the UHPH-treated must, respectively. Furthermore, no fermentative activity was detected in the non-inoculated UHPH-treated musts for more than 50 days. A strong inactivation of the oxidative enzymes was observed, with lower oxidation (≈ × 3) than controls. The antioxidant activity of the UHPH-treated must was much higher (106%) than that of the control must. UHPH had a protective effect in total anthocyanins, and especially in acylated anthocyanins (+ 9.3%); furthermore, the fermentation produces fewer higher alcohol (-44,3%) and more 2-phenylethyl acetate (+ 63%).

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 vinifera L. cv Garnacha, reducing the initial population by 1-log CFU/mL and, in most cases, maintaining a high viable population at the end of fermentation of the inoculated non-Saccharomyces. Several specific yeast metabolites produced by the inoculated non-Saccharomyces yeasts were found at higher levels in the PEF-processed musts, thus indicating a better implantation of these yeasts. The main differences have been found not only in some esters such as ethyl lactate, 2-phenyl ethyl acetate, and ethyl acetate but also in the lactic acid concentration for Lachancea thermotolerans inocula.

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, organic acids, biogenic amines or sulphur dioxide. An improvement in the performance of the electrodes, increasing their sensitivity, accuracy and selectivity, together with shorter response times and less pre-treatment of the sample are some of the main advantages of using nanoparticles in detection devices. There are many nanomaterials (e.g. carbon nanodots or nanotubes, gold, silver, zinc oxide, iron oxide nanoparticles or nanocomposites) with interesting and varied properties that allow making specific detections and measurements of compounds while developing simpler analysis methodologies. In addition, other utilities of nanotechnology such as the development of electronic tongues, the nano-liquid chromatography, the antimicrobial power of certain nanoparticles and nanocomposites, the removal of yeast lees in sparkling wines through the attachment of magnetic nanoparticles, the usefulness of mesoporous silica nanomaterials as clarifying agents and the possibility of creating molecularly imprinted templates for the selective extraction of specific compounds from wine have been studied.

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. During 8 months, the total polyphenol index (TPI), color parameters, anthocyanins and pyranoanthocyanins, and wood aromatic compounds were periodically evaluated. The measurement of the TPI and color parameters was similar in all wines, but significant differences were found in total anthocyanin and vitisin content and in certain aromatic compounds belonging to volatile phenols, furanic compounds, and phenolic aldehydes. The results obtained indicate the need for the winemaker to carry out preliminary tests in order to be able to choose the wood that best suits the sensorial profile of the wine.

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 lactic acid productions of 1–7 g/L. Additionally, the sugar metabolization into lactic acid instead of ethanol results in a slight reduction of the alcoholic degree (0.2%–0.5% vol). Most of the strains have a medium fermentative power, which generally reaches up to 10% vol; however, some strains can exceed this value. The resistance to SO2 is quite good, with many strains able to ferment at concentrations of 40–60 mg/L. The production of volatile acidity is low and frequently lower than 0.4 g/L. Some effects on wine aroma can be observed by the production of fermentative esters. L. thermotolerans is a powerful biotool to improve wine acidity and freshness, which is currently a hot topic in the enology of wine areas affected by global warming.

Currently, one of the major concerns in the wine industry is the high use of sulfur dioxide (SO2) during white winemaking as an antimicrobial and antioxidant agent. Ultra high pressure homogenization (UHPH) is an emerging nonthermal technique for continuous processing of liquid foods that could partially or totally replace the use of this enological additive. Among the main advantages provided by the application of UHPH in white vinification are the sterilization of the must, oxidation control, nutritional enrichment of the must, absence of sensory degradation, better implementation of the different fermentation biotechnologies, and deseasonalization of production. Despite causing strong reductions in particle size to reach 100–300 nm, which generates a greater initial clouding of both the must and the wine, it does not pose any additional problems when it comes to clarification and filtration. The result at the microbiological level is similar to that obtained by conventional thermal sterilization but without the disadvantages of nutritional and sensory degradation associated with the increase in temperature. It is therefore a technique with great versatility and potential for application in the enological industry.

Pulsed light is an emerging technology used to limit the proliferation of microorganisms in food matrices. The treatment consists on the emission of ultra-short high intensity white light pulses. The light is composed by ultraviolet, visible and near infrared spectra. Its use in enology allows the winemaker to carry on ternary (simultaneous) and sequential fermentations. The PL working conditions were determined through this investigation at the same time that the implantation feasibility of yeast and bacteria for the acidification of red wine was assed. The experimental set up evaluated different doses (number of pulses and energy density) on destemmed grapes. The grapes were placed inside a laboratory-scale cabinet inside a tray and the grapes were mixed randomly three times within the treatment. The microorganisms (both native and inoculated) were followed up with selective and differential growing media. The yeast population decreased 1.2 log10 UFC/mL, although the reduction is less sensitive when the initial population is already low (e.g. 1 × 102 UFC/mL). The use of PL favored the accumulation of lactic acid, produced by either yeast or bacteria, in treated musts. The concentration of lactic acid was higher when using L. thermotolerans against the use of O. oenni in coinoculation or sequential MLF.

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 accumulation of phenolic compounds, including pigments. Both technical approaches are alternatives involved in minimizing the effects of global climate change in warm areas. The increase of temperature related to climate change accelerates the accumulation of sugars, but produces unbalanced grapes. This work establishes the use of button sensors to monitor the climate changes occurring at grape cluster level. Together with climate monitoring, conventional instrumental analytical techniques are used to follow up the chemical composition and the phenolic fraction of grapes in four different production areas in Spain. The effect of either treatment seems variable and to be affected by external factors besides the treatment itself and the climate conditions. While there is a fine effect that correlates with the use of elicitors in varieties like Merlot and Tempranillo, there is minimal improvement observed in Tintilla de Rota. The total phenolic index increases were between 2.3% and 11.8% in the first two parcels. The same happened with the vineyard’s canopy management systems, with increased pigment accumulation and the total phenolic index rising (37.7% to 68.7%) after applying intense shoot trimming, or a variation in sugar concentrations when using sprawl conduction. This study aims to provide viticulturists and oenologists in particular, and farmers in general, with data on the field regarding the use of alternative sustainable practices in the cultivation of grapes. The techniques used involved 100% natural products without adjuvants. The benefits obtained from applying some of these practices would be to produce technically mature grapes despite climate changes, and the elaboration of more balanced 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. When MLF was running with populations of either 7 or 8 log CFU/mL strain alpha (Oenococcus oeni) the application of 600 mg/L of fumaric acid stopped the process for more than 50 days and cells were undetected in specific media. In triangular tastings, fumaric acid was not detected at 300–600 mg/L (p < .05). In subsequent preference tests, some tasters perceived more acidity and body. Fumaric acid is a useful technological additive to improve wine microbiological stability and freshness, also allowing reduction of SO2 levels. Trujillo San Isidro

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 aromatic, of red wines suffer during the ageing on lees process assisted with ultrasounds and with the addition of oak chips. The results obtained during the experimental design indicate that the ultrasound treatment decreased the concentration of proanthocyanidins (between 20.3% and 32.8% with and without oak chips, respectively) and the total pigment content (with the highest reduction in the control sonicated wine 55.9% without chips and lees and from 47.8% to 48.9% when having oak chips/lees and lees, respectively). In addition, it has been observed that the ultrasound treatment did not affect the amount of fermentative volatile compounds present in the wine but, it increased the concentration of phenolic aldehydes coming from oak wood chips (10.8% in control wine and from 35.92% with oak chips/lees to 55.8% with lees).

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 accompanied by alcoholic degrees that are often higher than 14% vol. By yeast selection, we have obtained one strain of Lachancea (formerly Kluyveromyces) thermotolerans that reduces pH value approximately in 0.5 units making unnecessary the use of chemical acidification. The production of lactic acid by this strain is done using sugars as precursors, thus affecting the final alcoholic degree. Some collateral reduction of ethanol can be achieved, up to 0.5% v/v. The efficiency of this strain is higher than that of others commercially available today. The use of L. thermotolerans sequentially with Saccharomyces cerevisiae is a powerful tool to modulate acidity and ethanol in warm areas. In this work, the effectivity to reduce pH of a specific strain of L. thermotolerans has been verified in low and high pH musts in lab trials but also in semi-industrial fermentations with crushed grapes.

Ultra-High Pressure Homogenization (UHPH) is a fast and efficient technique that can sterilizefluid foods at lowtemperatures or even under cooling conditions. A white must (Vitis viniferaL.) was processed at 300 MPa (inlettemperature 20 °C, in-valve temperature 98 °C, outlet temperature 25 °C, and time in valve 0.02 s) and theirperformance was compared with two untreated controls, a must that underwent a spontaneous fermentation(without SO2addition) and another must that was sulfited with 35 mg/L of total SO2and inoculated with thesameSaccharomyces cerevisiaeyeast as the UHPH-treated must. UHPH treatment led to the total elimination ofgrape microorganisms considering an initial population of 1 × 106CFU/mL in average of wild yeasts and fungiin must, and approximately 7 × 103CFU/mL of background bacteria. In a parallel assay, UHPH-processed mustwithout yeast inoculation showed absence of fermentation for eight days at 18 °C. The musts treated with UHPHshowed a lighter appearance (10%) before fermentation compared to the control. The triangular test verified theexistence of sensory differences between the wines obtained and the preference tests showed that the judgesfound the wine obtained from the UHPH-treated must more fruity (3.5/5 compared with 1.5–2 in controls) andwith better aroma.Industrial relevance:UHPH is an interesting way to process the must before fermentation allowing the reductionof sulfite addition while controlling wild and spoilage microorganisms. info:eu-repo/semantics/acceptedVersion

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 SO2 requirements at the same time. In this experimental set up, Tempranillo grapes were subjected to pulsed light treatment, and the fermentative performance of non-Saccharomyces yeasts belonging to the species Schizosaccharomyces pombe, Lachancea thermotolerans, Torulaspora delbrueckii, Metschnikowia pulcherrima and Hanseniaspora vineae was monitored in sequential fermentations against spontaneous fermentation and pure culture fermentation with the species Saccharomyces cerevisiae. The experimental analyses comprised the determination of anthocyanin (High performance liquid chromatography with photodiode array detector—HPLC-DAD), polyphenol index and colour (Ultraviolet-visible spectroscopy—UV-Vis spectrophotometer), fermentation-derived volatiles (Gas chromatography with flame ionization detector—GC-FID), oenological parameters (Fourier transform Infrared spectroscopy—FT-IR) and structural damage of the skin (atomic force microscopy—AFM). The results showed a decrease of 1.2 log CFU/mL yeast counts after pulsed light treatment and more rapid and controlled fermentation kinetics in musts from treated grapes than in untreated samples. The fermentations done with treated grapes allowed starter cultures to better implant in the must, although a larger anthocyanin loss (up to 93%) and an increase in hue values (1 unit) towards more yellow hues were observed for treated grapes. The development of biomass was larger in musts from treated grapes. The profile of volatile compounds and oenological parameters reveals that fermentations carried out with untreated grapes are prone to deviations from native microbiota (e.g., production of lactic acid). Finally, no severe damage on the skin was observed with the AFM on treated grapes.

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 with sensory quality of grapes. High hydrostatic pressure (HHP), ultra high pressure homogenization (UHPH), pulsed electric fields (PEFs), electron-beam irradiation (eBeam), ultrasound (US), and pulsed light (PL) have interesting advantages and some drawbacks that are extensively reviewed highlighting the potential applications in current technology.

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 vineae and sequential inoculation with Saccharomyces cerevisiae have been used to study the formation of terpenes and cell lysis in the production of Albillo white wines. The GC-MS analysis profile shows a significant effect of H. vineae fermentation on the contents of terpenes (≈×3), mainly in linalool (&gt, ×3), β-citronellol (&gt, ×4), geraniol (&gt, ×2) and α-terpineol (≈×2). The contents of several polyoxygenated terpenes and some volatile phenols with a spicy aroma were increased during fermentation. In summary, Hanseniaspora vineae releases a large number of cell wall polysaccharides during fermentation that affect wine palatability and structure. Hanseniaspora vineae is a powerful bio-tool to enhance the fruitiness, floral notes and freshness in non-aromatic white varieties.

The use of UHPH sterilization in the absence of SO

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.

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. In this regard, the right selection of yeast strains plays an important role in meeting these parameters and obtaining wines with fresher profiles. Another approach in getting fresh wines is through the use of novel non-thermal technologies during winemaking. Herein, the contributions of non-Saccharomyces yeasts and emerging technologies to these parameters are reviewed and discussed.

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 with non-Saccharomyces species, as Lachancea thermotolerans, described the intense effect of some strains on anthocyanin’s color, and subsequent, stability, by strongly reducing wine’s pH during fermentation. Moreover, selected yeast strains of Saccharomyces have been shown to release metabolites such as pyruvic acid or acetaldehyde that promote the formation of vitisin A and B pyranoanthocyanins during must fermentation. Schizosaccharomyces pombe, because of its specific metabolism, can produce higher concentrations of pyruvate, which enhances the formation of vitisin A-type derivatives. The hydroxycinnamate decarboxylase activity that some Saccharomyces strains express during fermentation also promotes the formation of vinylphenolic derivatives. Some non-Saccharomyces species, such as S. pombe or P. guilliermondii can also improve the production of these derivatives compared to selected strains of Saccharomyces cerevisiae. Lastly, some yeasts are also able to modulate the formations of polymeric pigments between grape anthocyanins and flavonoids, such as catechins and procyanidins.

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 white base wine made from Vitis Vinifera cv. Airen grapes and red base wine made from Vitis Vinifera cv. Tempranillo grapes, in the bottle were followed by aging on lees during 4 months at 12 °C. Finally, physicochemical properties were analyzed and a sensory evaluation was held. Significant differences were detected among sparkling wines produced with the studied yeasts in acidity parameters and non-volatile compounds. The pyranoanthocyanin content and color intensity was higher with the use of Schizosaccharomyces pombe in red sparkling wines. The total amount of volatile compounds was similar among treatments, but in certain compounds, individual variations in concentration were seen. Total amount of biogenic amines decreased in all the samples after the treatment. Differences were also detected in sensory evaluation; the sparkling wines produced with Saccharomyces cerevisiae showed different aromatic profile in comparison to sparkling wines produced with Schizosaccharomyces pombe, considering the parameters of limpidity, aroma intensity, aroma quality, flowery, fruity, buttery and reduction aromas in white samples; color intensity, limpidity, aroma intensity, herbal, buttery, yeasty, and oxidation aromas in red samples. Usage of non-Saccharomyces yeasts for sparkling wine production with traditional method can be furtherly studied to change specific characteristics of sparkling wines without decreasing their overall quality and obtain differentiation.

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 approach Grapes normally show a typical wild microorganism population of log 2–4 cfu/mL in yeasts and fungus, log 2 in bacteria, mainly LAB. The use of emerging technologies such as high hydrostatic pressure, ultrasounds, pulsed electric fields, pulsed light, UV irradiation, e-beam irradiation, ozone and electrolyzed water destroy or strongly minimize the initial wild microbiota allowing more hygienic winemaking processes. Frequently, these technologies increase the extraction of phenolic compounds and aromatic molecules improving sensory quality. Also facilitate dose reduction of some chemical additives widely used in oenology and with allergenic properties like sulphur dioxide. Moreover, new winemaking biotechnologies like the use of non- Saccharomyces yeasts or yeast-bacteria co-inoculations can be facilitated in either grape or must fermentations with low microbial loads. Key findings and conclusions This review highlights some useful novel strategies to improve the phenolic extraction during maceration-fermentation processes and to reduce natural microflora present in grape must allowing the better implantation and performance of selected yeast strains.

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 evaluation of wines made by non-Saccharomyces yeast under different fermentation trials compared to wines made by Saccharomyces cerevisiae. Single pure fermentations were performed by two strains of S. cerevisiae (used as controls) and two strains of Schizosaccharomyces pombe. The yeasts Lachancea thermotolerans and Torulaspora delbrueckii were tested in sequential fermentations with S. cerevisiae strains. The effect on acidity due to the interaction between L. thermotolerans and S. pombe in a mixed fermentation was studied. Sequential fermentations with L. thermotolerans and S. cerevisiae can reduce the ethanol content and increase the content of glycerol and pyruvic acid; in addition, the use of L. thermotolerans can increase the lactic acid content, while the mixed fermentations of S. pombe and L. thermotolerans may increase the acetaldehyde content and may also reduce the ethanol content. However, these samples require more time to complete the fermentation. Single pure fermentations by S. pombe can increase the amounts of vitisins, acetaldehyde and glycerol and the amounts of acetic acid. The use of L. thermotolerans in a sequential fermentation allowed an increase in fruitiness and body character of red wine.

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 were inoculated and fermented with Saccharomyces cerevisiae following fermentation during 2 weeks with skins and seeds. Temperature was set at 22 °C. PL treatments control wild microorganisms, especially yeasts, facilitating the growth and development of the yeast starter affecting wine quality. PL treatments of grapes can help to increase the shelf-life in postharvest technology but also improve fermentative purity and wine quality. PL is cheaper and easier to scale-up at winery than high hydrostatic pressure, pulsed electric fields or e-beam irradiation.

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. Cell disruption due to sonication was verified by optical microscopy. Volatile acidity, total polyphenol index, color intensity, tonality, dissolved oxygen, anthocyanins, and fermentative volatiles were monitored throughout the ageing of the wines. Sensory analysis was performed at the end of the ageing process. Polysaccharides released from the cell walls and the oxygen consumption, was quantified using a hydroalcoholic solution. The results indicated a 20% increase of the polysaccharide content and suggested an increase in the antioxidant capacity of the lees. No significant changes were observed in the fermentative volatile compounds and the total polyphenol index (TPI), except for those wines in contact with wood. The sonication of lees had some protective effect on the total anthocyanins content, however, color intensity was significantly lower in the sonicated treatments. The sonication of the lees did not cause any defect at the sensory level. Therefore, sonication could allow a reduction in the SO2 addition to wine, as well as a shortening of the ageing times. Keywords: ultrasound (US); sonicated lees; ageing on lees (AOL); polysaccharides; dissolved oxygen; phenolics; volatiles; oak wood chips; sensory profile

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. This chapter reviews the technology and processes used in vermouth making highlighting the repercussion on the sensory quality. The effect of traditional herbs and spices on its sensory profile is also studied. Moreover, the effect of base wine in the aromatic complexity and stability is analyzed. The use of the caramel as colorant is compared with natural alternative products as grape anthocyanins in terms of stability, sensory quality, and consumer preferences. Finally, the use of barrel aging or the use of alternative biological processes as aging on lees is also considered.

Red grape fermentation is a complex process in which the fermentation of sugars occurs at the same time as skin maceration together with seeds and eventually stems. Fermentation is a biological process produced by yeast, and maceration is a physicochemical process which requires the extraction of anthocyanins and tannins to obtain the color and structure typical of red wine. Control parameters of both processes are different, so it is necessary to optimize the compatible conditions to manage each of them. Temperature, mechanical operations, and aeration are useful to increase extraction and improve the final balance of phenolic compounds. The main drawback of conventional red wine making processes is the requirement to work with solids (skins and seeds). Emerging technologies not only facilitate the separation of solids with suitable extraction techniques, but at the same time reduce wild microorganisms. This allows an easier management of fermentation as well as the implementation of new biotechnologies such as non-Saccharomyces fermentations and yeast–bacteria coinoculations.

Aging on lees (AOL) involves the use of yeast lees that have fermented the wine, or have been exogenously produced to improve the sensory profile of wines. AOL improves astringency by softening tannins; it also increases structure because of yeast polysaccharides release. The production and addition of selected yeast lees allow for a reduction in microbiological alterations, speeding up the process and enabling the use of more convenient Saccharomyces and non-Saccharomyces yeasts. AOL is a slow process that can be accelerated with the use of emerging physical technologies such as high hydrostatic pressures and ultrasounds. Moreover, lees can be used as a vehicle to homogeneously and gently distribute aromatic wood compounds in wines.

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 foods. Recent studies confirm the beneficial effects of food with added live microbes (probiotics) in the modulation of various physiological functions to prevent chronical diseases. The mechanisms of action are variable, mainly by improving the microintestinal balance of the indigenous microflora and production of metabolic by-products at intestinal level. Alternative carriers of probiotics in beverages are proposed to meet the needs of health-conscious consumers. Nondairy-based probiotic, prebiotic, and symbiotic products are designed to overcome disadvantages of dairy products. Complementary approaches to thrive probiotics are concepts related to prebiotics and symbiotics, as a means to promote the proper environment for the survival and growth of both already established intestinal microbiota and externally administered ones. Special attention is paid on nondigestible food fraction that allows specific changes, both in probiotic composition and/or activity in the gut microbiome. These approaches are mainly targeted on promoting selectively the growth and/or activity of one or a limited number of beneficial bacteria in the colon. Biological roles of components of functional beverages relied on the metabolites generated by the interaction between phytochemicals and gut microbiota via esterase, glucosidase, demethylation, dihydroxylation, and decarboxylation activities thus exerting their noteworthy healthy effect through different mechanisms. Symbiotic functional beverages include those with combined probiotic and prebiotic food matrices that can act synergistically to modulate the intestinal microbiota positively.

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 Saccharomyces cerevisiae species. The characterization of both pyranoanthocyanin and polymeric pigments has been carried out with liquid chromatography coupled to mass spectroscopy (HPLC-DAD-ESI/MS). Red wines were also characterized by infrared spectroscopy (FTIR), gas chromatography (GC-FID) and spectrophotometry (UV-Vis). It has been observed that fermentation with the species Schizosaccharomyces pombe led to higher concentrations of pigments of all types: anthocyanins, polymeric pigments and pyranoanthocyanins, particularly vitisin A. Conclusions The use of non-Saccharomyces yeasts improve the formation of stable pigments in red wines thanks to the differences in the microbial metabolism from among the yeasts studied. Significance and Impact of Study Colour stability as one of the main organoleptic properties in red wines, may be improved by the controlled use of selected non-Saccharomyces yeasts during red must fermentation. This article is protected by copyright. All rights reserved.

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 HPLC-RI. Anthocyanins and aroma compounds were analysed by using HPLC-PDAD/ESI-MS and GC-FID respectively. Also colour and total phenolic index were recorded periodically along the experiment. The non-Saccharomyces strains of Schizosaccharomyces pombe, Saccharomycodes ludwigii and Dekkera bruxellensis showed better results with regards to the amount of polysaccharide release compared to the control Saccharomyces strains. Results showed that ultrasound treatment along with abrasive addition is a reliable technique for shortening the ageing on lees process by strongly increasing the concentration of polysaccharides released into the wine after only two weeks treatment and without adversely affecting the sensorial quality of the wine.

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 monovarietal wines from indigenous varieties, Yiannoudi and Maratheftiko, grown in the island of Cyprus from the vintages 2014, 2015 and 2016. The experimental analysis comprised the determination of anthocyanin&rsquo, s profile (high-performance liquid chromatography-diode array detection chromatography-electrospray ionization tandem mass spectrometry, HPLC-DAD-ESI/MS) and fermentation derived volatiles (gas chromatography-flame ionization detector, GC-FID) and a blind wine testing sensory evaluation. Both the analytical results and the blind wine tasting showed that wines, at their early stage, were easily differentiated by variety, especially in terms of anthocyanins composition, while, in aged wines, the differences among samples were influenced in time by the winemaking procedures and it was not possible to differentiate varieties in such conditions.

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. In this regard, the right selection of yeast strains plays an important role in meeting these parameters and obtaining wines with fresher profiles. Another approach in getting fresh wines is through the use of novel non-thermal technologies during winemaking. Herein, the contributions of non-Saccharomyces yeasts and emerging technologies to these parameters are reviewed and discussed.

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, such as high ethanol, low oxygen, and harsh osmotic conditions. The spoilage activity of this genus is also found in fruit juices, soft drinks, salad dressings, and other food products, producing besides package expansion due to gas production, non-desired compounds such as ethanol and esters. Despite these drawbacks, Zygosaccharomyces spp. produces high ethanol and acetoin content in wines and may play an important role as non-Saccharomyces yeasts in differentiated wine products. Control strategies, such as the use of antimicrobial peptides like Lactoferricin B (Lfcin B), the use of dimethyl dicarbonate (DMDC) or non-thermal sterilization techniques may control this spoilage genus in the food industry.

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 regulating the acidity of wine through maloalcoholic fermentation. In addition, this species is characterized by favouring the formation of stable pigments in the wine and releasing large quantities of polysaccharides during ageing on lees. Moreover, its urease activity and its competition for malic acid with lactic acid bacteria make it a safety tool by limiting the formation of ethyl carbamate and biogenic amines in wine. However, it also has certain disadvantages such as its low fermentation speed or the development of undesirable flavours and aromas. In this chapter, the main oenological uses of Schizosaccharomyces pombe that have been proposed in the last years will be reviewed and discussed.

Ice wines are widely distributed in cold regions. Austria, Germany, Switzerland, Canada, and China are producers of these wines. These wines are included in top international level quality premium wines because of their peculiar and delicate sensory features. These wines are enological jewels, fetching high prices in international markets, and the production regions and the climatic conditions in which they are produced can be included in extreme and heroic viticulture. Moreover, the highly concentrated must that is extracted from the frozen berries under pressure makes the fermentation biotechnology very difficult. The yeasts have great problems with the growth and development of their metabolism, which is a critical point of the ice wine making process. Management of extreme osmophilia in the must is one of the critical goals in the biotechnology of ice wines. In the end, the sensory quality and longevity of these sweet wines make them really special.

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. The experimental design carried out using white must corrected with the addition of malvidin-3-O-glucoside and flavanols, suggests that non-Saccharomyces yeasts are able to provide increased levels of colour intensity and larger polymeric pigment ratios and polymerization indexes. The selection of non-Saccharomyces genera, in particular Lachancea thermotolerans and Schizosaccharomyces pombe in sequential fermentation, have provided experimental wines with increased fruity esters, as well as producing wines with potential pigment compositions, even though there is an important reduction of total anthocyanins.

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 autolytic process in wine yeast. Furthermore, the effects of ultrasonic treatment on the organoleptic properties of a red wine aged on lees were also studied. The content of polysaccharides (HPLC–RI), anthocyanins (HPLC–PDAD/ESI–MS), volatile compounds (GC–FID), colour parameters (spectrophotometry) and sensory analysis was periodically evaluated. Results showed that ultrasound treatment is a reliable technique for shortening the ageing on lees process by strongly increasing the concentration of polysaccharides released into the wine after only 2 weeks of treatment and without adversely affecting the sensory quality of the wine. Furthermore, the addition of glass beads stood out as a good abrasive agent increasing the polysaccharides release up to 10 times the control when coupled with ultrasound treatment. Nevertheless, both stirring and microwave treatments were less effective, possibly due to the short period of application used. The impact of the alcoholic degree on the yeast autolysis was also evaluated, and, moreover, it was confirmed that moderate heating promotes a higher release of polysaccharides into the wine.

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. The main aim of this work was to evaluate the influence of sequential and mixed fermentations with Schizosaccharomyces pombe and Torulaspora delbrueckii strains on red wine's sensory quality. Anthocyanins and aromatic profiles, as well as glycerol and organic acid content, were analysed in the red wines obtained. Results show that, in general, mixed fermentations can promote an increment in polyols synthesis, while sequential fermentations can enhance the herbaceous aroma. Moreover, the use of T. delbrueckii in mixed fermentations allowed an increase to the fruity character of red wine. The use of S. pombe in sequential fermentations increased the stability of the colouring matter by favouring vitisins and vinylphenolic pyranoanthocyanin formation.

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 bacterial and yeast counts by 1 log cycle, while the 10 kGy dose left only a residual population of

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 AOL process. Ultrasound (US) has been used to improve different food industry processes; it could be interesting to accelerate the yeast autolysis during AOL. This work evaluates the use of the US technique together with AOL and oak chips for this purpose studying the effects of different oenological parameters of red wines. The results obtained indicate an increase of polysaccharides content when US is applied in wine AOL. In addition, total polyphenol index (TPI) and volatile acidity were not affected. However, this treatment increases the dissolved oxygen affecting the volatile compounds and total anthocyanins.