Chemical and volatile composition of lychee wines fermented with four commercial Saccharomyces cerevisiae yeast strains

This study evaluated the chemical and volatile composition of lychee wines fermented with four commercial yeast strains of Saccharomyces cerevisiae: EC‐1118, R2, 71B and MERIT.ferm. Yeast cell population, pH, malic acid, ammonia and some amino acids had significant differences between strain 71B and other strains. There were strain variations with regard to degradation and retention of some juice volatiles as well as formation of new volatile compounds such as most esters and certain terpene compounds. Ethyl octanoate had the highest odour activity value (OAV of 500–1100), followed by ethyl hexanoate (about 50–85), among the common odorants in all lychee wines. Ethyl octanoate reached its highest OAV (1077) in the lychee wine fermented with strain EC1118, whereas ethyl hexanoate had the highest OAV (85) in the wine fermented with strain MERIT.ferm. Cis‐rose oxide, the character‐impact volatile in lychee juice with highest OAV (161), was dramatically reduced to trace levels after fermentation.     

Fermentative behavior of Saccharomyces strains during microvinification of raspberry juice (Rubus idaeus L.)

Sixteen different strains of Saccharomyces cerevisiae and Saccharomyces bayanus were evaluated in the production of raspberry fruit wine. Raspberry juice sugar concentrations were adjusted to 16°Brix with a sucrose solution, and batch fermentations were performed at 22 °C. Various kinetic parameters, such as the conversion factors of the substrates into ethanol (Y_p/s), biomass (Y_x/s), glycerol (Y_g/s) and acetic acid (Y_ac/s), the volumetric productivity of ethanol (Q_p), the biomass productivity (P_x), and the fermentation efficiency (E_f) were calculated. Volatile compounds (alcohols, ethyl esters, acetates of higher alcohols and volatile fatty acids) were determined by gas chromatography (GC-FID). The highest values for the E_f, Y_p/s, Y_g/s, and Y_x/s parameters were obtained when strains commonly used in the fuel ethanol industry (S. cerevisiae PE-2, BG, SA, CAT-1, and VR-1) were used to ferment raspberry juice. S. cerevisiae strain UFLA FW 15, isolated from fruit, displayed similar results. Twenty-one volatile compounds were identified in raspberry wines. The highest concentrations of total volatile compounds were found in wines produced with S. cerevisiae strains UFLA FW 15 (87,435 μg/L), CAT-1 (80,317.01 μg/L), VR-1 (67,573.99 μg/L) and S. bayanus CBS 1505 (71,660.32 μg/L). The highest concentrations of ethyl esters were 454.33 μg/L, 440.33 μg/L and 438 μg/L for S. cerevisiae strains UFLA FW 15, VR-1 and BG, respectively. Similar to concentrations of ethyl esters, the highest concentrations of acetates (1927.67 μg/L) and higher alcohols (83,996.33 μg/L) were produced in raspberry wine from S. cerevisiae UFLA FW 15. The maximum concentration of volatile fatty acids was found in raspberry wine produced by S. cerevisiae strain VR-1. We conclude that S. cerevisiae strain UFLA FW 15 fermented raspberry juice and produced a fruit wine with low concentrations of acids and high concentrations of acetates, higher alcohols and ethyl esters.     

Fermentation Characteristics and Aromatic Profile of Plum Wines Produced with Indigenous Microbiota and Pure Cultures of Selected Yeast

The aim of this study was to assess and compare fermentation characteristics and aromatic profile of plum wines produced with indigenous microbiota and pure cultures of different selected yeast. Experiments were carried out with plum (Prunus domestica L.) varieties of different fruit ripening times (?a?anska rana, ?a?anska lepotica, and Po?ega?a). Wine fermentations were conducted by the activity of indigenous microbiota, commercially available Saccharomyces cerevisiae and Saccharomyces bayanus yeast strains and joint activity of Schizosaccharomyces pombe and S. cerevisiae (sequential inoculation). Statistically significant differences in fermentative characteristics and the content of certain volatile compounds were observed as a result of metabolic activity of various indigenous and/or selected yeasts during fermentation of plum pomace. Minimal duration of fermentation (4 to 5 d) and fastest ethanol production rate (from 12.3 to 15.5 g/L/d) were the characteristics of the studied S. cerevisiae strains. Isobutanol, 3‐methyl‐1‐butanol, 1‐heptanol, and 1‐octanol were the most prevalent higher alcohols in the tested plum wine samples. The predominant ester in plum wines was ethyl acetate, ethyl lactate, amyl acetate, isoamyl acetate, and ethyl palmitate, esters responsible for the floral and fruity olfactory tones, were also present in large amounts. Also, the use of S. cerevisiae strains resulted in the production of plum wines with better sensory characteristics than ones produced with other investigated yeasts. Obtained results are significant since there is limited data on the compounds responsible for the unique flavor of plum wine, as well as on the impact of different yeast starter cultures application on the overall quality of fruit wines.     

Sweet Wine Production by Two Osmotolerant Saccharomyces cerevisiae Strains

The use of Saccharomyces cerevisiae to produce sweet wine is difficult because yeast is affected by a hyperosmotic stress due to the high sugar concentrations in the fermenting must. One possible alternative could be the coimmobilization of the osmotolerant yeast strains S. cerevisiae X4 and X5 on Penicillium chrysogenum strain H3 (GRAS) for the partial fermentation of raisin musts. This immobilized has been, namely, as yeast biocapsules. Traditional sweet wine (that is, without fermentation of the must) and must partially fermented by free yeast cells were also used for comparison. Partially fermented sweet wines showed higher concentration of the volatile compounds than traditionally produced wines. The wines obtained by immobilized yeast cells reached minor concentrations of major alcohols than wines by free cells. The consumption of specific nitrogen compounds was dependent on yeast strain and the cellular immobilization. A principal component analysis shows that the compounds related to the response to osmotic stress (glycerol, acetaldehyde, acetoin, and butanediol) clearly differentiate the wines obtained with free yeasts but not the wines obtained with immobilized yeasts.     

Chemical,physical, and sensory attributes of Sauvignon blanc wine fermented in different kinds of vessels

The use of vessels that are alternative to conventional cylindrical stainless steel tanks and traditional oak barrels during winemaking has increased in recent years. Examples of these alternative vessels include fashionable, oval-shaped vessels or classic clay jars. A Sauvignon blanc grape juice was fermented (by using a commercial starter made of two different commercial strains from Oenobrands/Anchor Oenology) in four different vessels in triplicate: 150 L cylindrical stainless steel tanks (as a control), 980 L polyethylene oval-shaped tanks, 450 L concrete oval-shaped tanks, and 225 L clay jars. Afterwards, the finished wines were chemically, physically, and sensorially characterized. The wine fermented in the concrete vessels had a slightly higher pH (about 0.05 pH units) and lower titratable acidity (about 0.20 g/L of tartaric acid equivalents) value than those of the control wine. The wine fermented in the clay jars showed the lowest amounts of C₁₀, C₁₂, and C₁₄ volatile compounds (containing about 69% of those compounds when compared with the control wine). The wine fermented in the polyethylene oval-shaped tanks was described as the most bitter, while the wine fermented in the concrete oval-shaped tanks was described as the least fruity when wines were sensory analyzed by a panel of 11 wine experts. The wines fermented in the oval-shaped vessels showed lower volatile acidity (about 25% reduction of volatile acidity when compared with wines fermented in non-oval-shaped vessels), higher residual sugars (wines fermented in the oval-shaped vessels contained about 1.7 g/L of residual sugars, while wines fermented in the non-oval-shaped vessels contained about 1.4 g/L of residual sugars), higher phosphorous content (with an increase of about 12%), and required a lower dose of bentonite to achieve protein stability (about 64 g/hL of bentonite) than those of the other wines (about 75 g/hL of bentonite). Even though some statistical differences were found among wines fermented in the different vessels, it should be noted that the differences were very small. Thus, it seems that the impact of the fermentation vessel type on final wine features is lower than expected.     

3 种酵母发酵生产红树莓酒香气成分的GC-MS分析

以D254、71B、D15 3 种果酒酵母进行发酵制备红树莓酒,并分析其香气化学成分。采用顶空-固相微萃取法提取3 种酵母酿造的红树莓酒香气成分;利用气相色谱-质谱进行香气成分的分离测定,结合计算机检索技术对分离化合物进行鉴定,利用峰面积归一法测定各香气化学成分的相对含量,共鉴定出105 种香气成分,其中D254、71B、D15酵母发酵的红树莓酒中分别检测出35、48、57 种香气成分,共有8 种成分相同。D254酵母发酵的红树莓酒的主要香气成分为3-甲基-1-丁醇（54.39%）;71B酵母发酵的红树莓酒的主要香气成分为丙烯酸异辛酯（12.41%）、脱羰秋水仙碱（12.06%）、癸酸乙酯（8.21%）;D15酵母发酵的红树莓酒的主要香气成分为三辛酸甘油酯（11.06%）和安非拉酮（8.81%）。综合气相色谱-质谱分析与感官评价结果表明,71B酵母发酵生产的红树莓酒香气较好,适宜大众口味,从而得出71B酵母为生产红树莓酒的最优菌株。     

Effects of seven yeast strains on the volatile composition of Palomino wines

The must obtained from Palomino grapes was inoculated with seven different commercial yeast strains (three Saccharomyces cerevisiae cerevisiae– MO5, CEG and IOC BR 8000 and four Saccharomyces cerevisiae bayanus– ALB, KD, REIMS and IOC 2007) and fermented under identical conditions. Standard chemical analyses were done on the final industrial wines and the major volatile compounds extracted and analysed by gas chromatography coupled to mass spectrometry. No differences were found in gross chemical composition, but the wines had significantly different volatile characteristics and the results demonstrated that large sensory differences were generated by the different yeast strain that had been used in the vinification. The major constituents that contributed to the volatile composition in this wine were the higher alcohols, ethyl esters, acetates, fatty acids and volatile phenols. In terms of floral and fruity odours, the best results were obtained for the wines inoculated with IOC 2007, ALB and REIMS S. cer. bayanus strain.     

Study of the content in volatile compounds during the aging of sweet Sherry wines obtained from grapes cv. Muscat and fermented under different conditions

Several experiments of aging in oak wood and stainless steel of sweet Sherry wines obtained from grapes cv. Muscat fermented under different enological conditions have been carried out. These wines were periodically sampled and their volatile content was analyzed using SBSE–GC–MS. A sensory study was also carried out. Data were submitted to different statistical techniques. An important influence of the three factors considered, fermentation type, aging type, and aging time, have been observed. In cluster analysis, the grouping obtained demonstrated that the volatile compounds considered possess sufficient explanatory power to detect the type of aging process and differentiate the two yeast strains studied. In the case of the linear discriminant analysis, high percentages of correct classification were obtained for the three factors considered. Taking into account the global volatile profile, the factor “aging type” (oak cask or stainless steel) has demonstrated the highest influence on the volatile content of the wines, with those wines from Experiments D4 and D5 (fermented with S. bayanus) and aged in oak wood clearly differentiated from those ones fermented with S. cerevisiae and aged in wood or stainless steel. From a sensorial point of view, the wines fermented with S. Cerevisiae and aged in wood (D1C and D2C) were the most valued ones.     

Effects of cofermentation and sequential inoculation of Saccharomyces bayanus and Torulaspora delbruckii on durian wine composition

This work investigated the effects of cofermentation and sequential inoculation of Torulaspora delbrueckiiBiodiva and Saccharomyces bayanusEC‐1118 on chemical and volatile components of durian wines. Cofermentation and sequential inoculation resulted in higher production of ethanol (6.2% and 7.7% v/v, respectively) relative to the control (5.3% for S. bayanus and 5.8% for T. delbrueckii). Further, cofermentation and sequential inoculation produced higher amounts of acetyl esters and higher alcohols especially isoamyl alcohol and 2‐phenylethyl alcohol than monoculture fermentation. Most endogenous sulphur volatiles, especially disulphides that impart a character‐impact durian odour, declined to trace levels, but new ones such as thioesters were formed. Sulphur volatiles in the durian wines fermented by cofermentation and sequential inoculation accounted for 0.03% and 0.05% of total peak area. The study suggests that the use of S. bayanus in conjunction with non‐Saccharomyces such as T. delbrueckii may improve the aromatic intensity and complexity of durian wine.     

Impact of malolactic fermentation on the volatile composition of Turkish Kalecik karası red wines

The effects of spontaneous malolactic fermentation (MLF) and a malolactic starter culture (Oenococcus oeni) on the volatile compounds of Kalecik karas? red wines were investigated. The volatile compounds were extracted using liquid–liquid extraction and quantified by GC–MS–flame ionisation detection. Starter cultures of O. oeni had a positive effect in shortening MLF and producing lower volatile acidity. After MLF, the total volatile compounds increased in both the inoculated wines and the spontaneously fermented wine. Ethyl lactate, diethyl succinate and γ‐butyrolactone increased upon inoculation with cultures of O. oeni strains PN4 and VP41. MLF increased the diacetyl concentration in all Kalecik karas? wines. Strain dependent differences were found in the level of diacetyl, with O. oeni PN4 producing more diacetyl than O. oeni VP41. After MLF, the concentrations of acetoin, 4‐ethylguaicol and 4‐ethylphenol increased in spontaneously fermented wine compared with wines inoculated with O. oeni. Accordingly, the use O. oeni PN4 is recommended for a controlled MLF to produce better quality Kalecik karas? wines. © 2018 The Institute of Brewing & Distilling     

不同酿酒酵母发酵桃果酒香气成分研究

采用SPME-GC-MS技术分析选育酿酒酵母J11和4株商品活性干酵母分别酿造的桃果酒,5种桃果酒共检测出100种挥发性香气物质,包括醇类、酯类、酸类、羰基化合物、苯系化合物以及萜类化合物。结果表明醇类和酯类是桃果酒挥发性物质的主要组分,异戊醇、辛酸乙酯、癸酸乙酯以及9-癸烯酸乙酯是桃果酒的主要香气物质。5种桃果酒中,选育酵母J11酿造的果酒更好地保留了桃果实自身的风味,且其香气物质的种类和含量都是最高的,证明与其他4种商品酵母比较,选育酵母J11更适合桃果酒的酿造。      

Impact of yeast starter formulations on the production of volatile compounds during wine fermentation

The most diffused starter formulation in winemaking is actually represented by active dry yeast (ADY). Spray‐drying has been reported as an appropriate preservation method for yeast and other micro‐organisms. Despite the numerous advantages of this method, the high air temperatures used can negatively affect cell viability and the fermentative performance of dried cells. In the present study, 11 wine S. cerevisiae strains (both indigenous and commercial) were submitted to spray‐drying; different process conditions were tested in order to select the conditions allowing the highest strain survival. The strains exhibited high variability for tolerance to spray‐drying treatment. Selected strains were tested in fermentation at laboratory scale in different formulations (free fresh cells, free dried cells, immobilized fresh cells and immobilized dried cells), in order to assess the influence of starter formulation on fermentative fitness of strains and aromatic quality of wine. The analysis of volatile fraction in the experimental wines produced by selected strains in different formulations allowed identification of > 50 aromatic compounds (alcohols, esters, ketones, aldehydes and terpenes). The results obtained showed that the starter formulation significantly influenced the content of volatile compounds. In particular, the wines obtained by strains in dried forms (as both free and immobilized cells) contained higher numbers of volatile compounds than wines obtained from fresh cells. Copyright © 2014 John Wiley & Sons, Ltd.     

Effect of autochthonous starter cultures on the volatile flavour compounds of Chinese traditional fermented fish (Suan yu)

Effect of autochthonous starter cultures on the volatile flavour compounds of Chinese traditional fermented fish was studied. Lactobacillus plantarum 120, Staphylococcus xylosus 135 and Saccharomyces cerevisiae 31, isolated from Suan yu, were selected as starter cultures. Volatiles were extracted by headspace solid‐phase microextraction (SPME) and analysed by gas chromatography–mass spectrometry technology (GC‐MS). Esters and alcohols were the main components of volatiles, accounting for over 50 percentage points in all samples. The highest content of esters (3034.54 μg kg^?1) was observed in S1 inoculated with L. plantarum 120, while the highest content of alcohols (2164.53 μg kg^?1) and ketones (379.98 μg kg^?1) was detected in S3 inoculated with S. cerevisiae 31. The content of acids and aldehydes was lower in inoculated samples. Principal component analysis revealed that the volatile composition was primarily influenced by the nature of the starter cultures. L. plantarum 120 and S. xylosus 135 could accelerate fermentation.     

Analysis of characteristic aroma of fungal fermented Fuzhuan brick‐tea by gas chromatography/mass spectrophotometry

Fuzhuan brick‐tea is a popular fermented Chinese dark tea because of its typical fungal aroma. Fungal growth during the production process is the key step in achieving the unique colour, aroma and taste of Fuzhuan brick‐tea. To further understand the generation of the characteristic aroma, changes in the main volatile compounds of Fuzhuan brick‐tea during the fungal growth stage were studied by gas chromatography/mass spectrophotometry. The results showed that the content of volatile compounds, especially aldehyde compounds with stale aroma such as (E)‐2‐pentenal, (E)‐2‐hexenal, 1‐penten‐3‐ol, (E, E)‐2,4‐heptadienal and (E, Z)‐2,4‐heptadienal, increased significantly in fermented tea samples. The concentration of terpene alcohols with flower aroma also increased notably during the fermentation process. The compounds with stale and flower aromas in combination with some volatile components of the raw material contributed to the characteristic ‘fungal/flower’ aroma of Fuzhuan brick‐tea. Microbial metabolism during the fermentation process probably played the key role in the generation of characteristic aromatic compounds of Fuzhuan brick‐tea. Copyright © 2007 Society of Chemical Industry     

Analysis of characteristic flavour compounds in Chinese rice wines and representative fungi in wheat Qu samples from different regions

The volatile flavour compounds of different Chinese traditional rice wines and the corresponding representative fungi in the wheat Qu (comparable to the koji used in sake brewing) samples were investigated. Results showed that alcohols, acids and esters were abundantly present in the three Chinese rice wines, but the types and concentrations of the volatile flavour compounds by fermentation from different wheat Qu samples were quite distinctive. Cladosporium cladosporioides, Penicillium chrysogenum, Aspergillus oryzae and Saccharomyces cerevisiae were the major components of the fungal flora in the three kinds of wheat Qu samples. Less prevalent genera and species represented in the fungal communities of the three kinds of wheat Qu samples, however, varied greatly, and the richer the flavour substances in the rice wines were, the more abundant the microbe species in the corresponding wheat Qu samples. The results indicate that the types and concentrations of volatile compounds were significantly influenced by the species of microorganisms (moulds and yeasts) in the wheat Qu, which brings a unique flavour to Chinese rice wine. Copyright © 2012 The Institute of Brewing & Distilling     

二氧化碳浸渍法对于蓝莓酒香气成分影响研究

采用顶空固相微萃取和气相色谱-质谱联用技术,分析传统法和二氧化碳浸渍法酿造的蓝莓酒中的香气成分,共检测出80种香气物质,其中传统法中检测到61种香气物质,在二氧化碳浸渍10 d、15 d、20 d的蓝莓酒中分别检测到55种、65种、61种香气物质。采用气相色谱峰面积归一定量法计算两种方法所酿造的蓝莓酒香气成分的相对含量,发现两者香气组成差别较大,并且浸渍15 d为宜。二氧化碳浸渍法酿造的蓝莓酒中酯类和萜烯类含量高于传统法,较传统法蓝莓酒更具有清新优雅的特点。     

Influence of sequential inoculation of Wickerhamomyces anomalus and Saccharomyces cerevisiae in the quality of red wines

The use of mixed inoculation of non-Saccharomyces yeasts and S. cerevisiae in wine fermentations is of increasing interest for quality enhancement and improved complexity of wines. The effect of sequential inoculation of Wickerhamomyces anomalus (formerly Hansenula anomala) with interesting enological properties in terms of secondary metabolite production and a commercial S. cerevisiae strain in fermentation of non-sterilized red musts from Mazuela variety has been examined. The wines elaborated by sequential inoculation presented higher levels of acetates and ethyl esters, compounds that supply a fruity note, higher levels of lineal alcohols, which are responsible for herbaceous notes and lower concentrations of organic acids, that contribute to increase the aromatic quality, than wines produced by a S. cerevisiae monoculture. Both types of wines were comparable in levels of volatile acidity, glycerol, lactic acid and succinic acid produced. Sensory analysis showed that red wines obtained by mixed fermentations were preferred by 71.5 % of the tasters and were particularly appreciated for its floral and/or fruity notes.     

Characteristics and antioxidant capacities of five hawthorn wines fermented by different wine yeasts

Different yeast strains can influence the characteristics and active constituents of hawthorn wines. Hawthorn wines were produced using five different yeasts and characterized in terms of their profiles of typical properties and antioxidant capacities. The wine antioxidant capacities of 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), 2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid, superoxide anion (O₂ · ^–) scavenging activities and ferric reducing antioxidant power (FRAP) were determined. It was found that the general wine compositions showed the expected variations. Except for yeast Lalvin W15 all of the yeasts exhibited good sugar‐utilizing ability and alcohol production. Yeast Lalvin 71B exhibited an excellent fermentation capability. Hawthorn wine fermented by yeast Lalvin 71B had the lowest residual sugar, titratable acidity and colour density and the highest alcohol content. SIHA Active Yeast 3 had good performance in respect to oxidation resistance. The highest content of anthocyanins and polyphenols in the wine was found with hawthorn wine fermented by SIHA Active Yeast 3, and this wine contained the highest antioxidant activity as determined by the DPPH assay, O₂ · ^– assay and FRAP. Statistical analysis indicated that pH value was significantly correlated with colour density (?0.954**) and alcohol content (0.905**) in the hawthorn wines. There was a strong positive correlation between the polyphenol content and the antioxidant activity as determined by the DPPH (0.915**) and FRAP (0.914**) assays, respectively. Copyright © 2013 The Institute of Brewing & Distilling.     

Evaluation of sequential inoculation of Saccharomyces cerevisiae and Oenococcus oeni strains on the chemical and aromatic profiles of cherry wines

The current study was carried out to elucidate the effect of sequential inoculation of Saccharomyces cerevisiae (RC212, D254) and Oenococcus oeni (SG26, Lalvin 31 and Uvaferm Alpha) on the production of cherry wines, especially on the chemical and aromatic characteristics. SI-D culture required the shortest period (23 d) to complete the fermentation, while other inoculations needed longer time. Analysis from chemical composition showed that titratable acidity and content of l-malic acid exhibited evident differences among the samples after MLF. For volatile compounds, 49 major components were identified, mostly comprising of alcohols, acids and esters. Cherry wines obtained from SI-B and SI-C showed higher contents of total volatile alcohols, and SI-D wines produced the greatest amount of volatile acids. According to the odour active value (OAV), 9 out of 49 studied volatile components had OAV >1 in all the analyzed wines, while six volatile components showed OAV >1 only for some of them. Furthermore, a sensory analysis was performed to compare the sensory profile of these cherry wines, and results evidenced that wines resulting from different inoculations presented diverse sensory profiles. These findings suggest that sequential inoculations posed a great potential in affecting and modulating the aromatic profile of cherry wines.