Prefermentative Cold Maceration Research Articles

Influence of Cryoextraction and Cold Pre-Fermentative Maceration on the Yeast Microbiota and the Volatile Compounds Profile of Sangiovese Wine

Low-temperature treatments can be applied to grapes or must before alcoholic fermentation to enhance the wine’s sensory characteristics. Several studies have shown that such practices have a positive effect on the polyphenol profile of the wine, but only a few surveys have examined the effect of these treatments on the yeast microbiota of grapes and wine. Therefore, this study aimed to evaluate how cryoextraction (freezing the grape with liquid nitrogen) and cold pre-fermentative maceration (at 5 °C for 48 h) affect the Saccharomyces and non-Saccharomyces populations during the winemaking process of red grapes, cv Sangiovese, conducted at two temperatures (20 and 30 °C). This research analyzed the concentration of various yeast species, their fermentation abilities, and the resulting wine’s aromatic profile. The Principal Component Analysis performed on yeast concentrations during the fermentations of various wines did not group the experimental wines based on treatment. However, the same groupings were highlighted when the concentrations of the volatile compounds, quantified in the experimental wines, were processed using the same statistical approach. Therefore, cryoextraction and cold pre-fermentative maceration seem to contribute less to the aromatic profile than the yeasts involved in the fermentation process.

Influence of Cold Pre-Fermentation Maceration on the Volatilomic Pattern and Aroma of White Wines.

Aroma compounds play a key role in wine quality due to their importance in wine aroma. The aim of the present study is to investigate the influence of cold pre-fermentative maceration (CPM) treatment on aromatic and sensory properties of white wines from four grape varieties (Tempranillo Blanco, Maturana Blanca, Viura and Garnacha Blanca) during two consecutive years (2019 and 2020). A total of 62 aroma compounds belonging to different chemical families were identified using headspace solid-phase microextraction combined with gas chromatography mass spectrometry (HS-SPME/GC-MS). CPM treatment enhanced the total relative concentration of alcohols, esters and acids compared to control wines. Regarding sensorial properties, esters made the greatest contribution to the studied white wines, mainly through the development of floral and fruity notes. On the other hand, CPM treatment did not significantly influence the total relative concentration of terpenoids, and different trends were observed according to grape variety and vintage. The obtained results showed differences in the wine's aromatic complexity according to the grape variety, the vintage and the treatment applied and suggested that CPM treatment could represent a suitable approach to manipulate the aromatic profile and enhance the aromatic quality and complexity of wine.

Influence of Prefermentative Cold Maceration on the Chemical and Sensory Properties of Red Wines Produced in Warm Climates

Red wines produced in warm climates generally possess a lower content of phenolic compounds and color structure than those produced in colder climates, which hinders bottle evolution. To improve these properties, cold maceration could be a useful procedure. To study the effect of this technique, Tempranillo, Merlot and Syrah grape varieties cultivated in the Jerez area (Southwest Spain) were cold macerated at 4 °C for ten days before alcoholic fermentation. Their composition and characteristics compared to the directly fermented control grapes were analyzed for phenolic content, color, volatile compounds, and sensory properties. It has been verified that phenolic content increased by around 10% during the treatment, which was maintained after the alcohol fermentation, along with an increase in color intensity and aromatic profile. This modification on the composition provided better scores for appearance, aroma intensity, and aroma quality in sensory analysis. The evolution of all studied parameters during 12 months of aging in the bottle is also studied, confirming the advantages of this technique in preserving the compositional and sensory characteristics throughout the period studied.

Impact of rutin and buckwheat (Fagopyrum esculentum) extract applications on the volatile and phenolic composition of wine

The aim of this research is to study the possibility of increasing the quality of red wins made with the Monastrell grape variety. A methodology was established to improve the concentration levels of polyphenol and aroma in these wines. Among flavonoids, the copigmenting effect of rutin stands out, and was tested in both winery and field applications. Buckwheat extract (Fagopyrum esculentum), in which rutin is the main flavonoid, may be of interest for viticulture given its biological activity.This paper focuses on researching the effect of applying the prefermentative vegetable extract of buckwheat (Fagopyrum esculentum) on the concentration of polyphenols and aroma compounds in vineyards. Simultaneously, a study was carried out to compare the effect of pure copigment (rutin) when applied in vineyards and cellars. Traditional vinification was done, plus prefermentative cold maceration.The application of buckwheat extract, and rutin extract to a lesser extent, to Monastrell grapes increased the concentration of malvidin and other anthocyanins, and total anthocyanins. After 12-month storage, no differences were observed in the percentage of copigmented, polymerised and free anthocyanin, the total polyphenol concentration, and the tannin quality parameters like DMACH (aldehyde p-dimethylaminoacimaldehyde) and the Gelatin Index. The concentrations of diethyl succinate, 2 phenylethyl acetate, vanillin and ethyl octanoate increased, while other compounds decreased when the copigment was added. The maceration technique followed during the vinification process had very little effect on polyphenolic compounds. The prefermentative maceration slightly increasing the concentration of total polyphenols, but had no effect on the parameters related to colour, anthocyanin concentration, nature of anthocyanins, their binding state or tannin quality parameters. The results showed that cold prefermentation maceration increased the concentration of some volatile compounds, including alcohols and esters, which should be considered important contributors to Monastrell wine aroma.The combination of the applying buckwheat extract and pure rutin together, and prefermentative cold maceration, positively affects the polyphenolic concentration and increases the concentration of quality volatile compounds.

Application of green tea extract and catechin on the polyphenolic and volatile composition of Monastrell red wines

SummaryThe present work studies the effect of adding catechin and plant extract rich in catechin, Camellia sinensis (green tea) extract, on the volatile and polyphenolic composition of red wines made from Monastrell grapes. The aim of this research is to study the way to increase the red wine quality made with Monastrell variety of grapes. In one of them, the green tea extract was applied to grapes in vineyards 10 days before harvest. In another, catechin was applied to vineyards in the same way, and finally, catechin was applied during grape processing. Each trial was fermented by traditional vinification and prefermentative maceration for 5 days prior to alcoholic fermentation. A simple ANOVA analysis was used to evaluate if the application of copigments and winemaking techniques influenced wine composition. In addition, a multifactorial ANOVA was used to study the copigment treatment effect x winemaking technique interaction. Wine polyphenolic and volatile composition were analysed 12 months after fermentation. The application of green tea extract and catechin to vineyards increased (13%–16%) the concentration of anthocyanins in relation to the control to a greater extent when the initial polyphenolic concentration of grapes was lower. The volatile concentration rose when copigments (green tea extract and pure catechin) were applied to vineyards, in particular, hexyl acetate, ethyl octanoate and vanillin. The application of techniques like prefermentative maceration enhances the effects of copigments added to vineyards. The combination of the application of green extract or pure catechin with prefermentative cold maceration, had positive effects increasing polyphenols and volatile compounds concentration.

Effect of the cold pre-fermentative maceration and aging on lees times on the phenolic compound profile, antioxidant capacity and color of red sparkling wines.

This was the first study evaluating the impact of cold pre-fermentative maceration using refrigeration on the nutraceutical quality and color of red sparkling wines elaborated with the cultivar Syrah, and the evolution of these variables with different autolysis times. The sparkling wines were elaborated using the traditional method with different maceration times (NM, 24 and 72 h) and aging on lees (3 and 18 months of autolysis). In the sequence, it was conducted the characterization of the phenolic compound profile by HPLC–DAD (n = 21), the antioxidant capacity (ABTS, DPPH, and FRAP assays), and the color (CIELab and CIEL*C*h systems). The total phenolic content (TPC) and antioxidant capacity (AOX) were higher with longer maceration (M72) and autolysis (18 months) times, reaching 453.54 mg L−1 of TPC, and AOX above 2.11 mmol TEAC L−1 by the three in vitro assays conducted. Cis-resveratrol, kaempferol-3-O-glucoside, quercetin-3-β-d-glucoside, isorhamnetin-3-O-glucoside, and petunidin-3-O-glucoside showed a good correlation (r > 0.8; P < 0.05) with the antioxidant capacity and were found in higher concentrations in the sparkling wines elaborated with maceration. In addition, maceration promoted a more intense red (a*) and saturated (C*) color. Thus, the results indicated that cold pre-fermentative maceration and autolysis positively influenced the bioactive potential and the color of the red sparkling wines. This practice should be better explored through the elaboration of this product.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13197-022-05531-z.

Different approaches to supplement polysaccharide-degrading enzymes in vinification: Effects on color extraction, phenolic composition, antioxidant activity and sensory profiles of Malbec wines

Enzymes play an essential role in the winemaking process. Besides an improvement in the color of the wine it also enhances the quality, which makes it well worth to develop new strategies of application. The present study examined two approaches to apply microbial enzymes during different winemaking techniques using Malbec grapes from the San Rafael wine region, Mendoza, Argentina. i) Torulaspora delbrueckii was used in sequential inoculation with an autochthonous Saccharomyces cerevisiae strain. The former strain was first inoculated to produce in situ an enzyme complex during winemaking for four days, and subsequently the latter strain was added. The process was carried out under traditional winemaking conditions at 22 °C (Td-Sc). ii) A second approach was through inoculation of a multi-enzyme extract produced by Aureobasidium pullulans m11-2 during pre-fermentative cold maceration (PCM) for four days at 8 °C (PCM-E), and S. cerevisiae was inoculated at the end of the PCM. Controls were carried out without enzymatic treatments (Sc and PMC, respectively). T. delbrueckii started the fermentation and remained viable throughout the process. The fermentation kinetics were not affected in the mixed culture compared with a pure culture of S. cerevisiae. Monitoring of the pectinolytic activity of Td-Sc showed maximum activity (14.2 U mg−1) on day one of the inoculation, while in PCM-E the must activity increased during the PCM until day one of fermentation, reaching a maximum of 16.85 U mg−1. Both enzyme-treated wines maintained their red hue, regardless of the duration of the macerations, while the control wines were characterized by a faster rate of color loss and more yellow tones. In the sensory evaluation, enzymatically treated wines presented greater color intensity, redder and more violet tones, floral and fruit aromas, which are also the distinctive features of the Malbec variety. Anthocyanin values obtained in PCM and in PCM-E were higher than in vinifications without cold maceration (Td-Sc and Sc), which could be attributed to the effectiveness of the maceration technique. Similarly, the composition of stilbenes, especially trans-resveratrol, showed an increase in PCM techniques with or without enzymatic treatment, and both techniques were comparable to one other and statistically superior to traditional winemaking.

PHYSICOCHEMICAL AND SENSORY CHARACTERISTICS OF ROSÉ SPARKLING WINE PRODUCED WITH MERLOT GRAPES IN “CAMPANHA GAÚCHA”

This work evaluated the potential of the Merlot grape produced in Campanha Gaúcha region for the production of sparkling wines. The base wines were made through direct pressing (T1) and cold pre-fermentative maceration (CPM) with 6 (T2), 24 (T3) and 48 (T4) hours of duration. Afterwards, the second fermentation of treatments was conducted by the Champenoise method. The results obtained in the physicochemical analysis demonstrate the potential of elaborating sparkling wines with higher alcohol content from this cultivar in the region. In the sensory analysis, all sparkling wines received excellent scores for overall quality and the best results, in general, were observed in the sparkling wine made with 24 hours of CPM (T3). From the results obtained, we can suggest the Merlot grape as an alternative for the production of sparkling wines in the region, requiring more in-depth studies on maturation time and typology of the product to be prepared.

Pre-Fermentative Cold Maceration and Native Non-Saccharomyces Yeasts as a Tool to Enhance Aroma and Sensory Attributes of Chardonnay Wine

The oenological potential of native strains of Metschnikowia pulcherrima B-5 and Candida famata WB-1, isolated from blackberries, was investigated in pure and sequential fermentation of Chardonnay grape with commercial Saccharomyces cerevisiae QA23. The effect of pre-fermentative cold maceration was also analysed. The fermentations were performed in the pilot-scale trials and the profile of volatile compounds and their sensory characteristics were determined. The application of C. famata WB-1 and M. pulcherrima B-5 reduced the volatile acidity and increased total polyphenols of the wines, compared to the control samples. Higher alcohols and esters were dominant, while fatty acids and aldehydes and ketones were also detected. Esters had the greatest contribution to sensory characteristics, especially the development of floral and fruity aromas. Most esters were present in lower concentrations in sequential fermentations compared to the pure fermentations with M. pulcherrima B-5 or C. famata WB-1. Pre-fermentative maceration positively affected both the aroma and the sensory profile. The best sensory score was determined for wines produced using C. famata WB-1 in the fermentations without pre-fermentative maceration, and the sequential fermentation of M. pulcherrima B-5 with maceration. Native strains of M. pulcherrima B-5 and C. famata WB-1 have shown great potential for the enhancement of the aromatic and sensory profile of Chardonnay wine.

Comparison of different maceration and non-maceration treatments for enhancement of phenolic composition, colour intensity, and taste attributes of Malvazija istarska (Vitis vinifera L.) white wines

To investigate the effect of several vinification techniques aimed to enhance wine phenolic profile and sensory quality, maceration treatments of different duration and temperature (pre-fermentative cold one day maceration at 10 °C, seven days maceration at 16 °C, and prolonged post-fermentative 21 day maceration at 16 °C) and non-maceration treatments including tannin addition and late harvest grapes vinification were performed and compared to a standard white grape processing treatment. Produced wines were subjected to the analysis of phenols by high-performance liquid chromatography, colour intensity, and quantitative descriptive and hedonic sensory analysis. The increase in individual phenolic compound concentrations was mostly pronounced in maceration treatment wines, for both phenolic acids and flavan-3-ols, as well as for the sum of phenolic compound concentrations determined by high-performance liquid chromatography that tripled in relation to that determined in control treatment wine. Pre-fermentative cold maceration led to a moderate increase in phenolic compounds content without accentuating bitterness and astringency sensations. Wine phenolic composition and colour intensity were mostly affected by the prolonged post-fermentative 21 day maceration. Vinification of late harvest grapes produced a wine graded with the highest positive score for taste. The obtained distinct wine styles resulting from the application of the investigated practices may lead to a further diversification of white wine market.

Application of a grape surface majority pectinolytic species, Aureobasidium pullulans, to low-temperature red winemaking: development and stability of wine colour

ABSTRACT Low-temperature red winemaking is mainly used for enhancing the wine aroma; however, colour and phenolic extraction is reduced under this condition. This work evaluated the effects of the pectinolytic strain Aureobasidium pullulans GM-R-22, belonging to the most abundant species in grape surface and the greatest pectinase producer, applied to pre-fermentative cold maceration and low-temperature fermentation, on anthocyanin extraction, chromatic and technological properties, also on sensory attributes of Malbec wines. A. pullulans demonstrated to survive in grape juice and first days of fermentation, and high levels of pectinase activity were detected in GM-R-22 vinifications. GM-R-22 wines exhibited higher total anthocyanins, total polyphenolic index and colour intensity (CI), as well as filtration times 30% lower. GM-R-22 wines showed an increase in monomeric anthocyanins during fermentation and higher polymeric pigments at 9 months of bottle storage, suggesting a greater stability in wine colour. From a sensory standpoint, GM-R-22 wines obtained higher scores for CI and violet hue than their respective controls, improving aroma and equilibrium. This study proved that it is feasible to use this unconventional microorganism in oenology to produce pectinases during the low-temperature winemaking process to attain wines with similar or better chromatic properties to those of traditional wines.

Pinot Blanc: Impact of the Winemaking Variables on the Evolution of the Phenolic, Volatile and Sensory Profiles.

The impact of two different winemaking practices on the chemical and sensory complexity of Pinot Blanc wines from South Tyrol (Italy), from grape pressing to the bottled wine stored for nine months, was studied. New chemical markers of Pinot blanc were identified: astilbin and trans-caftaric acid differentiated the wines according to the vinification; S-glutathionylcaftaric acid correlated with the temporal trends. Fluorescence analysis displayed strong time-evolution and differentiation of the two wines for gallocatechin and epigallocatechin, respectively. After nine months of storage in bottle, the control wine showed higher amounts of most ethyl esters, acetate esters and octanoic acid, whereas higher alcohols characterized instead the wine obtained with prefermentative cold maceration. The sensory panel found notes of apple and tropical fruit in the control wine and attributed a higher overall quality judgement to it, whereas the cold-macerated wine was described by olfactory intensity, spicy and pear attributes.

Evolution of Phenolic Content, Antioxidant Capacity and Phenolic Profile during Cold Pre-fermentative Maceration and Subsequent Fermentation of Cabernet Sauvignon Red Wine

The phenolic compound profile and content of red wines are modified during the maceration-fermentation process by several factors that alter the extractability of the compounds and by reactions that phenolic compounds undergo, and can be directly related to the quality of the final wine and its beneficial effects on the consumer. The aim of this study was to determine the change in phenolic content and profile during cold pre-fermentative maceration and fermentation without the removal of grape pomace. Total phenolics, flavonoids, anthocyanins, tannins and antioxidant capacity were determined by spectrophotometric methods, and the phenolic profile was determined by HPLC-MS on each day of the maceration-fermentation process. The results showed a variation in the content of phenolic compounds and antioxidant activity over time, but the final phenolic content showed no significative difference compared with the initial content (1 268 mg GAE/L and 1 115 mg GAE/L respectively). The phenolic profile showed that flavonoids were the principal compounds in wine and that they increased at the end of the winemaking. Condensed tannins also increased during fermentation, while anthocyanins and some phenolic acids decreased at the end of the process. The final content of phenolic compounds was similar to the initial one, but there was a change in the different fractions of phenolic compounds at the end of fermentation.

Elicitors and Pre-Fermentative Cold Maceration: Effects on Polyphenol Concentration in Monastrell Grapes and Wines.

Vitis vinifera L cv Monastrell is the main red grape variety grown for vinification in the Denomination of Origin Jumilla (southeast Spain). Different strategies are still being tested to optimize available resources both in terms of the environment and to achieve wines with better organoleptic and functional characteristics. The objective of this work was to combine two strategies: the application of methyl jasmonate (MeJ), benzothiadiazole (BTH), and methyl jasmonate + benzothiadiazole (MeJ + BTH) elicitors to Monastrell leaves, and pre-fermentative cold maceration. During two seasons, the experiment was carried out to improve the extraction of the phenolic compounds, whose levels may have increased following the application of elicitors in the field, and to assess the effect of both strategies on the wine quality. Discriminant analysis revealed that independently of the meteorological conditions during both years, the pre-harvest response to the application of elicitors MeJ, BTH, and MeJ + BTH, induced increases in total anthocyanin concentration of the treated grapes, allowing the distinction of the treatments. This analysis also allowed the distinction between the types of maceration used, showing greater extraction of phenolic compounds by the application of low temperature, giving wines with a higher index of total phenols, a greater intensity of color, and a lower luminosity.

Comparative study of aromatic and polyphenolic profiles of Croatian white wines produced by cold maceration

Aroma profiles and phenolic components of white wines made from ’Pošip’ and ’Škrlet’ (Vitis vinifera L.) both native Croatian, non-aromatic grape varieties enhances the knowledge about these varieties, prepared without maceration (control) and subjected to the pre-fermentative cold maceration (CM). Individual phenolic compounds in wines were determined by high-performance liquid chromatography (HPLC) system, while total phenolics and flavan-3-ols in wines were determined by spectrophotometric methods. CM had the significant impact on the total phenolic and flavan-3-ols composition of ’Škrlet’ wine. The significant increase of some individual phenolic compounds was observed in ’Pošip’ wine. Volatile aroma compounds in wines were determined by gas chromatography (GC) with the previous extraction on the solid phase micro extraction (SPME). The primary aroma compounds, i.e. terpenes were under the significant influence of CM process in ’Škrlet’ wine. Aroma profiles, based on the content of 24 specific compounds, grouped in eight aroma series that contribute to wine odor were developed. CM significantly increased five aroma series in ’Škrlet’ wine and only three in ’Pošip’ wine.

Volatile composition, foam characteristics and sensory properties of Tempranillo red sparkling wines elaborated using different techniques to obtain the base wines

The aim of this work was to study oenological techniques to obtain adequate base wine for red sparkling wine elaboration. Four winemaking techniques were carried out: pre-fermentative cold maceration with dry ice and delestage with premature grapes; and sugar reduction in must and partial dealcoholisation of wine with mature grapes. Their effect on oenological parameters, volatile composition, foam and sensory characteristics was valuated. Reduction of sugar content and partial dealcoholisation allow obtaining base wines with more adequate alcohol content. No differences were found between the oenological parameters during the ageing time. Pre-fermentative cold maceration and partial dealcoholisation had a greater influence on the volatile composition of the base and red sparkling wines. Oenological technique did not affect the foam instrumental parameters. Red sparkling wines from premature grapes showed higher vegetal aromas, and pre-fermentative cold maceration the best foam sensory descriptors.

Kluyveromyces marxianus Secretes a Pectinase in Shiraz Grape Must That Impacts Technological Properties and Aroma Profile of Wine.

Since Saccharomyces cerevisiae strains display no to weak pectinase activity, the utilization of external pectinase is a common practice in winemaking to enhance the extraction of compounds located in the grape berry skins during maceration. In this study, the activity of the native endopolygalacturonase of a Kluyveromyces marxianus strain, isolated from grape juice, was characterized in Shiraz grape must during alcoholic fermentation with or without prefermentative cold maceration. The wines made with K. marxianus had a higher methanol concentration, more free-run wine, an altered volatile compound profile, and displayed pectinase activity in cell-free wine samples. Moreover, the results strongly suggest that K. marxianus' pectinase released polygalacturonic acid soluble fragments, unlike fungal pectinases, which mostly release monomers. Overall, this study shows that K. marxianus is an effective pectinase producer in wine with potential benefits for wine properties.

Kinetic and metabolic behaviour of the pectinolytic strain Aureobasidium pullulans GM-R-22 during pre-fermentative cold maceration and its effect on red wine quality

Pectinolytic yeasts can be applied to winemaking with the purpose of improving sensory and technological properties of wine because of their enzymes secreted during vinification. In this work, the autochthonous yeast-like pectinolytic strain from D.O. San Rafael viticulture region, Aureobasidium pullulans GM-R-22, was used in co-culture with Saccharomyces cerevisiae IOC 18-2007 in microvinification trials with Malbec must applying pre-fermentative cold maceration (PCM). A. pullulans remained viable during PCM and S. cerevisiae growth and fermentative kinetics were not affected in mixed culture with respect to pure S. cerevisiae culture. High pectinolytic activity (9.13 U/mg) was detected in mixed A. pullulans vinification during PCM, in which conditions of low temperature (8 °C), low pH (3.8) and high sugar concentration (250.6 g/L) governed. Mixed A. pullulans wine showed enhanced colour compared with pure S. cerevisiae wine, characterised by higher colour index and percentage of red colour, lower tonality and percentage of yellow colour, and negative values of b* and h* indicating more bluish and purplish tonalities. Moreover, filtration time and turbidity diminished by a 40% in mixed A. pullulans wine. The presence of GM-R-22 strain improved the production of desirable volatile compounds, such as esters and norisoprenoids, which displayed the maximum odour activity values (OAVs), whereas this strain reduced the total content of higher alcohols when compared to pure S. cerevisiae fermentation. Sensory analysis indicated that A. pullulans impacted on wine highlighting the violet hue, plum jam aroma, body and equilibrium that are distinctive features of Malbec variety. A. pullulans GM-R-22 seems to be promising for applying to low-temperature red winemaking as an adjunct culture to S. cerevisiae to improve the wine quality and vinification process.

Pre-fermentative cold maceration in presence of non-Saccharomyces strains: Evolution of chromatic characteristics of Sangiovese red wine elaborated by sequential inoculation

Two different Metschnikowia strains (M. pulcherrima MP 346 or M. fructicola MF 98-3) were applied for the first time, during pre-fermentative cold maceration (PCM) in order to enhance the properties and stability of Sangiovese wine color. During the 2014 and 2015 vintages a total of eight wines were produced with 24 h of cold maceration (PCM 24 h) or 72 h (PCM 72 h), respectively. PCM was carried out in presence of MP 346 or MF 98-3 or pectic enzyme (Cuvée Rouge). The sequential inoculation of S. cerevisiae strain was carried out at the end of PCM. After 12 months in the bottle, the MP 346 and MF 98-3 wines contained much higher levels of total flavonoids than the Control sample for both vintages and regardless PCM duration. Moreover, in both vintages only MF 98-3 showed a higher color intensity than the Control sample after 12 months in the bottle. However, neither PCM duration nor the microbial/enzymatic treatment increased the level of anthocyanins at draining off. Both wines produced by the pre-fermentative inoculum with Metschnikowia strains (MP 346 and MF 98-3) retained their red hue, regardless the duration of pre-fermentative and fermentative macerations, while the Control wines were characterized by faster rates of color loss.

Pre-fermentative cold maceration in the presence of non-Saccharomyces strains: effect on fermentation behaviour and volatile composition of a red wine

Background and Aims This study evaluated the impact of pre-fermentative cold maceration (PCM), in the presence of two non-Saccharomyces yeasts, Metschnikowia pulcherrima MP 346 and Metschnikowia fructicola MF 98-3, and of a commercial pectic enzyme, on fermentation kinetics and on the volatile composition of a Sangiovese red wine. Methods and Results Sangiovese grape must was inoculated with MP 346 or MF 98-3 or treated with a pectic enzyme preparation during PCM, at 5°C for 24 or 72 h. A Control wine was produced by a pure culture of Saccharomyces cerevisiae. Both non-Saccharomyces strains affected the initial yeast population dynamics and the persistence of S. cerevisiae at the end of malolactic fermentation. Irrespective of the duration of PCM, the inoculum of Metschnikowia strains did not influence the rate of sugar consumption or the kinetics of malolactic fermentation. The volatile composition of the final wines was evaluated with solid-phase extraction, followed by GC/MS. The concentration of some terpenes and C13-norisoprenoids, nerol, geraniol, 8-hydroxy-linalool (cis) and 3-oxo-α-ionol, and of some esters, isoamyl lactate and ethyl isoamyl succinate, was higher in wines inoculated with Metschnikowia strains than in the Control and wine treated with pectic enzyme. Conclusions Metschnikowia yeast strains MP 346 and MF 98-3 affect wine volatile composition. Significance of the Study This study shows for the first time that an inoculum of Metschnikowia strains MP 346 and MF 98-3 during PCM is effective in modulating the volatile composition of a Sangiovese red wine.