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1.
Neutral Salt Effects on Stability of Whey Protein Isolate Foams 总被引:4,自引:0,他引:4
Addition of 0.1 M Na2SO4, NaCl, or NaSCN reduced maximum overruns of whey protein isolate (WPI) by 33%, 27%, and 38%. This was attributable to an ionic effect, i.e., the ions interacted with countercharges on the proteins thereby reducing electrostatic interactions. In contrast, at high concentrations (1M), Na2SO4 improved foam stability by 76% compared to WPI without salt. Chloride had an intermediate effect, whereas NaSCN did not improve foam stability. Increasing Na2SO4 concentration (2M) improved foam stability by 127% compared to control. The relative effectiveness of salts at improving foam stability and heat stability followed the Hofmeister series (SO42-??). 相似文献
2.
Prihardi Kahar Kazuo Taku Shuzo Tanaka 《Journal of Bioscience and Bioengineering》2010,110(4):453-458
In this study, the effect and the optimum pretreatment condition of corncobs using low strength of H2SO4 were investigated, in which H2SO4 was used to improve the enzymatic digestibility of corncobs for saccharification without degradation of sugars released. The optimum pretreatment condition was found to be the addition of 0.5% (vol./vol.) H2SO4 and autoclaving at 122 °C for 20 min. Under this condition, the structural integrity of corncob was altered to make cellulose microfibrils more accessible for cellulase enzymes, and the enzymatic digestion of corncobs could be significantly enhanced. A high yield of sugar, 80% (wt./wt.), could be obtained at a low enzyme dosage of 0.024 g enzymes/g cobs, when pretreated. As a result, the ethanol production was obviously improved by the pretreatment, i.e., the ethanol yield of 77% (wt./wt.) was obtained within 36 h in the SSF fermentation using Saccharomyces cerevisiae NBRC2114. 相似文献
3.
Biodiversity of 17 Zymomonas mobilis strains isolated from French “framboisé” ciders from 7 different geographical areas of France was analysed using random amplified polymorphic DNA (RAPD) and 6 different strain fingerprints were observed. One of the fingerprints was identical for 10 of the 17 cases. No correlation between geographical origin and strain fingerprint was observed. In parallel, the cider-making process was followed from the orchard to the final product for Z. mobilis presence. Detection of the bacterium only occurred during the fermentation process. The French isolate, strain AN0101, recently proposed as a novel subspecies (Z. mobilis subsp. francensis) was characterized in a synthetic medium using various growth conditions that can be encountered during cider-making (T (°C), pH, ethanol, SO2, polyphenols) to determine growth limits. Results clearly showed that cider is in a risk zone for Z. mobilis contamination as this bacterium was able to grow at temperatures as low as 4 °C, in pH range from 3.5 to 6.0, in 0-8 ml/100 ml ethanol, at the legal limit of 200 mg/l SO2 and in the presence of a cider marc polyphenol extract up to 3 g/l. These results should allow for a better understanding of Z. mobilis conditions of contamination in cider and lead to possible preventive measures in the future. 相似文献
4.
Whasley F. Duarte Giuliano Dragone José M. Oliveira João B. Almeida e Silva 《International journal of food microbiology》2010,143(3):173-182
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 (Yp/s), biomass (Yx/s), glycerol (Yg/s) and acetic acid (Yac/s), the volumetric productivity of ethanol (Qp), the biomass productivity (Px), and the fermentation efficiency (Ef) 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 Ef, Yp/s, Yg/s, and Yx/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. 相似文献
5.
Multifactorial analysis of acetaldehyde kinetics during alcoholic fermentation by Saccharomyces cerevisiae 总被引:1,自引:0,他引:1
J.N. JackowetzS. Dierschke R. Mira de Orduña 《Food research international (Ottawa, Ont.)》2011,44(1):310-316
Acetaldehyde is the terminal electron acceptor in the alcoholic fermentation by Saccharomyces cerevisiae. Quantitatively the most important carbonyl by-product, it has relevance for ethanol production yields as well as product stabilization and toxicology. The aim of this study was to investigate the effect of various enological parameters on acetaldehyde kinetics during alcoholic fermentations. Two commercial yeast strains were tested in two grape musts and the pH, temperature, SO2 and nutrient addition were varied. All incubations had uniform kinetics where acetaldehyde reached an initial peak value followed by partial reutilization. Peak acetaldehyde concentrations and residual concentrations after 15 days of fermentations ranged from 62 to 119 mg l− 1 and 22 to 49 mg l− 1, respectively. A positive linear relationship was found between peak and final acetaldehyde levels in Gewürztraminer, but not Sauvignon Blanc fermentations, where sluggish fermentations were observed. Several factors had a significant effect on peak and/or final acetaldehyde levels. SO2 addition, grape cultivar and fermentation nutrition were important regulators of peak acetaldehyde production, while final acetaldehyde concentrations were correlated with SO2 addition, grape cultivar and temperature. The results allowed to estimate the acetaldehyde increase caused by SO2 addition to 366 ??g of acetaldehyde per mg of SO2 added to the must. The course of the final fermentation phase was shown to determine acetaldehyde residues. Comparison of acetaldehyde and hexose kinetics revealed a possible relationship between the time of occurrence of peak acetaldehyde concentrations and the divergence of glucose and fructose degradation rates. 相似文献
6.
Cappello MS Poltronieri P Blaiotta G Zacheo G 《International journal of food microbiology》2010,144(1):72-80
The knowledge about wine yeasts remains largely dominated by the extensive studies on Saccharomyces (S.) cerevisiae. Molecular methods, allowing discrimination of both species and strains in winemaking, can profitably be applied for characterization of the microflora occurring in winemaking and for monitoring the fermentation process. Recently, some novel yeast isolates have been described as hybrid between S. cerevisiae and Saccharomyces species, leaving the Saccharomyces strains containing non-Saccharomyces hybrids essentially unexplored. In this study, we have analyzed a yeast strain isolated from “Primitivo” grape (http://www.ispa.cnr.it/index.php?page=collezioni&lang=en accession number 12998) and we found that, in addition to the S. cerevisiae genome, it has acquired genetic material from a non-Saccharomyces species. The study was focused on the analysis of chromosomal and mitochondrial gene sequences (ITS and 26S rRNA, SSU and COXII, ACTIN-1 and TEF), 2D-PAGE mitochondrial proteins, and spore viability. The results allowed us to formulate the hypothesis that in the MSH199 isolate a DNA containing an rDNA sequence from Hanseniaspora vineae, a non-Saccharomyces yeast, was incorporated through homologous recombination in the grape environment where yeast species are propagated. Moreover, physiological characterization showed that the MSH199 isolate possesses high technological quality traits (fermentation performance) and glycerol production, resistance to ethanol, SO2 and temperature) useful for industrial application. 相似文献
7.
采用双水相萃取葡萄籽中原花青素,首先研究双水相萃取体系组成、辅助萃取方法、萃取策略对原花青素萃取效果的影响,并采用正交试验对原花青素萃取条件进行优化。结果表明,双水相萃取体系组成为无水乙醇/硫酸铵,辅助萃取方法为微波辅助法,萃取策略为乙醇+水+葡萄籽微波处理后加入硫酸铵,条件为无水乙醇/硫酸铵萃取体系为质量分数30%无水乙醇/质量分数20%硫酸铵,加入葡萄籽质量分数为3%,pH为4.0,微波功率100 W,微波时间5 min,在该条件下,葡萄籽中原花青素的萃取率为94.1%,得率为25.8mg/g; 相似文献
8.
Domizio P Romani C Lencioni L Comitini F Gobbi M Mannazzu I Ciani M 《International journal of food microbiology》2011,147(3):170-180
The use of non-Saccharomyces yeasts that are generally considered as spoilage yeasts, in association with Saccharomyces cerevisiae for grape must fermentation was here evaluated. Analysis of the main oenological characteristics of pure cultures of 55 yeasts belonging to the genera Hanseniaspora, Pichia, Saccharomycodes and Zygosaccharomyces revealed wide biodiversity within each genus. Moreover, many of these non-Saccharomyces strains had interesting oenological properties in terms of fermentation purity, and ethanol and secondary metabolite production. The use of four non-Saccharomyces yeasts (one per genus) in mixed cultures with a commercial S. cerevisiae strain at different S. cerevisiae/non-Saccharomyces inoculum ratios was investigated. This revealed that most of the compounds normally produced at high concentrations by pure cultures of non-Saccharomyces, and which are considered detrimental to wine quality, do not reach threshold taste levels in these mixed fermentations. On the other hand, the analytical profiles of the wines produced by these mixed cultures indicated that depending on the yeast species and the S. cerevisiae/non-Saccharomyces inoculum ratio, these non-Saccharomyces yeasts can be used to increase production of polysaccharides and to modulate the final concentrations of acetic acid and volatile compounds, such as ethyl acetate, phenyl-ethyl acetate, 2-phenyl ethanol, and 2-methyl 1-butanol. 相似文献
9.
Yingming Pan Zhiren Zhu Zhili Huang Hengshan Wang Ying Liang Kai Wang Qian Lei Min Liang 《Food chemistry》2009
A novel red pigment (RP) was isolated from Osmanthus fragrans ’ seeds. The optimised experimental parameters of extraction obtained with a four-factor at three-level orthogonal array experimental design L9(34) were ethanol concentration, temperature, pH and extraction time as 90%, 78 °C, 2.5 and 40 min, respectively. A yield of 34.6 ± 2.2 g/100 g was obtained under optimised conditions. The red pigment directly from O. fragrans’ seeds can be dissolved in alkaline, acidic waters solutions and hydrophilic organic solvents in common use. The colour of a water solution of RP changed with pH. RP was stable to heat in the temperature range of 25–100 °C. Physical and chemical properties of RP revealed that the red pigment was also stable in the presence of Na2SO3, NaCl, amino acid, organic acid, sugar, starch or metal-ions (such as Ca2+, Cu2+, Fe3+, Zn2+, Al3+, Mg2+ and Na+), but was bleached by strong oxidants (KMnO4, K2Cr2O7 and NaOCl). Subsequently, free radical scavenging activities of RP were assessed using 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals using a new resonance scattering spectral method. RP showed an excellent DPPH radical scavenging activity and was superior to butylated hydroxytoluene (BHT), and exhibited quite a strong concentration-dependent inhibition of hydroxyl radical at low concentrations compared with ascorbic acid and quercetin. When the concentration of RP was 0.03 μg/ml, the scavenging percentage of hydroxyl radical reached 92.3%. Salidroside was isolated as an active principle. 相似文献
10.
Annie W. Y. Cheung James M. Brosnan Trevor Phister Katherine A. Smart 《Journal of the Institute of Brewing》2012,118(2):152-162
Scotch whisky fermentations typically employ high‐gravity fermentation practices to maximize product formation and to minimize both energy and water inputs. This approach increases ethanol concentrations at the end of fermentation, creating stressful conditions for the yeast. In this work we examined the relative tolerance of four Saccharomyces cerevisiae distilling yeast strains, supplied in dried, creamed, cake or slurry format, to ethanol under CO2‐induced anaerobic conditions. The cells were assessed for their capacity to recover and grow on inhibition spot plates and to maintain cell viability in ethanol‐dosed suspensions. Variations in ethanol tolerance were observed between strains and between the same strain supplied in different formats. The creamed yeast format typically exhibited a higher tolerance to ethanol. One possible explanation for this observation is that cells surviving the dehydration and rehydration process might incur sub‐lethal genome damage. Thus the genetic integrity of the most ethanol‐tolerant strain was assessed as a function of supply format (two dried and one creamed). The mitochondrial DNA was examined using mitochondrial restriction fragment length polymorphism and the chromosomal DNA using pulsed field gel electrophoresis and polymerase chain reaction with both ITS and delta‐specific primers. In one dried yeast sample, genetic integrity was compromised, highlighting the requirement for yeast intake quality assurance programmes. Copyright © 2012 The Institute of Brewing & Distilling 相似文献
11.
Brennan M. Smith Scott R. Bean Gordon Selling David Sessa Fadi M. Aramouni 《Journal of food science》2017,82(3):613-621
Development of viscoelastic doughs from non‐wheat proteins allows for a wider range of gluten‐free products. Little work has been completed to describe mechanisms of zein functionality in food systems. To identify factors responsible for dough development in zein–starch mixtures and their influence on zein bread quality, a mixture of 20% zein–80% maize starch was mixed with water and various reagents. Salts, NaSCN, NaCl, and Na2SO4 were evaluated at concentrations from 0 to 2M for their influence on the properties of zein–starch dough systems. NaSCN at low concentrations produced softer dough. Ethanol treatments produced softer more workable dough in the absence of salts. Increasing concentrations of NaCl and Na2SO4 resulted in coalescing of the proteins and no dough formation. The addition of β‐ME had minimal softening effects on zein–starch dough. Specific volumes of zein–starch bread increased with decreasing NaCl addition in bread formulations. Likewise, including 5% ethanol (v/v) in the bread formula increased bread quality. 相似文献
12.
OS Lawal TA Afolabi KO Adebowale BM Ogunsanwo SA Bankole 《Journal of the science of food and agriculture》2005,85(15):2655-2659
Effects of selected Hofmeister anions, namely Na2SO4, NaCl, NaBr, NaI, NaClO4 and NaSCN, on the functional properties of a protein isolate prepared from lablab seeds (Lablab purpureus) were investigated. The results of water absorption capacity indicated that highest water absorption was recorded in solutions of Na2SO4, and the lowest in NaSCN solutions. Reduction in water absorption capacity followed the Hofmeister series in the order Na2SO4 > NaCl > NaBr, NaI > NaClO4 > NaSCN. Protein solutions prepared in chaotropic (NaI, NaClO4, NaSCN) salts had better foam capacity, foam stability, emulsifying activity and emulsion stability than solutions prepared with kosmotropic salts (Na2SO4, NaCl, NaBr). The results also indicate that increase in foam capacity and stability followed the Hofmeister series in the order Na2SO4 < NaCl < NaBr, NaI < NaClO4 < NaSCN. When least gelation concentration (LGC) was used as the index of gelation capacity, at various salts concentrations, the lowest LGC were observed in NaSCN and the highest LGC in protein solutions prepared with Na2SO4. Copyright © 2005 Society of Chemical Industry 相似文献
13.
Carrasco C Baudel H Peñarrieta M Solano C Tejeda L Roslander C Galbe M Lidén G 《Journal of Bioscience and Bioengineering》2011,111(2):167-174
Pretreatment, enzymatic hydrolysis and simultaneous saccharification and fermentation (SSF) of the South American straw material Paja Brava were investigated. Suitable process conditions for an SO2-catalyzed steam pretreatment of the material were determined and assessed by enzymatic digestibility of obtained fiber slurries for 72 h at a water insoluble solids (WIS) content of 2%. The best pretreatment conditions obtained (200°C, 5 min holding time and 2.5% SO2) gave an overall glucose yield following enzymatic hydrolysis of more than 90%, and a xylose yield of about 70%. Simultaneous saccharification and co-fermentation of glucose and xylose (SSCF) of the pretreated material using the xylose-fermenting strain Saccharomyces cerevisiae TMB3400 was examined at WIS contents between 5% and 10%. In agreement with previous studies on other materials, the overall ethanol yield and also the xylose conversion decreased somewhat with increasing WIS content in the SSCF. In batch SSCF, the xylose conversion obtained was almost 100% at 5% WIS content, but decreased to 69% at 10% WIS. The highest ethanol concentration obtained for a WIS content of 10% was about 40 g/L, corresponding to a yield of 0.41 g/g in a fed-batch SSCF. The Paja Brava material has previously been found difficult to hydrolyze in a dilute-acid process. However, the SSCF results obtained here show that similar sugar yields and fermentation performance can be expected from Paja Brava as from materials such as wheat straw, corn stover or sugarcane bagasse. 相似文献
14.
Fermentation of Soybean Meal Hydrolyzates with Saccharomyces cerevisiae and Zymomonas mobilis for Ethanol Production
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Deivis E. Luján‐Rhenals Rubén O. Morawicki Edward E. Gbur Steven C. Ricke 《Journal of food science》2015,80(7):E1512-E1518
Most of the ethanol currently produced by fermentation is derived from sugar cane, corn, or beets. However, it makes good ecological and economic sense to use the carbohydrates contained in by‐products and coproducts of the food processing industry for ethanol production. Soybean meal, a co‐product of the production of soybean oil, has a relatively high carbohydrate content that could be a reasonable substrate for ethanol production after fermentable sugars are released via hydrolysis. In this research, the capability of Saccharomyces cerevisiae NRRL Y‐2233 and Zymomonas mobilis subsp. mobilis NRRL B‐4286 to produce ethanol was evaluated using soybean meal hydrolyzates as substrates for the fermentation. These substrates were produced from the dilute‐acid hydrolysis of soybean meal at 135 °C for 45 min with 0, 0.5%, 1.25%, and 2% H2SO4 and at 120 °C for 30 min with 1.25% H2SO4. Kinetic parameters of the fermentation were estimated using the logistic model. Ethanol production using S. cerevisiae was highest with the substrates obtained at 135 °C, 45 min, and 0.5% H2SO4 and fermented for 8 h, 8 g/L (4 g ethanol/100 g fresh SBM), while Z. mobilis reached its maximum ethanol production, 9.2 g/L (4.6 g ethanol/100 g fresh SBM) in the first 20 h of fermentation with the same hydrolyzate. 相似文献
15.
Gongliang Liu Changli Tao Baosheng Zhu Weidong Bai Liangliang Zhang Zengpeng Wang Xingting Liang 《Food science and biotechnology》2016,25(6):1645-1650
To screen yeast with high sugar tolerance and evaluate their stress tolerance, six yeast strains were selected from 17 stored honey samples. The species were identified through 26S rRNA sequencing. Their stress tolerance was determined via the Durham fermentation method and ethanol production ability was determined via flask fermentation. The results demonstrated that all the six strains were Zygosaccharomyces mellis. Their sugar, ethanol, and acid tolerance ranges were 500–700 g/L, 10–12% (v/v), and pH 2.5–4.5, respectively. The SO2 tolerance was 250 mg/L. Among the six strains, 6-7431 had the best stress tolerance with sugar tolerance of 700 g/L, ethanol tolerance of 12% (v/v), and acid tolerance of pH 2.5. Furthermore, the strain of 6-7431 had the highest percentage of ethanol production at the same initial sugar content as the other strains. Therefore, the selected six yeast strains would be promising fermentation yeasts for wine-making, ethanol production, or other fermentation purposes. 相似文献
16.
Effect of pH and salt concentration on the solubility and density of egg yolk and plasma egg yolk 总被引:1,自引:0,他引:1
This work aimed to evaluate the solubility and density of egg yolk and plasma egg yolk in three types of salts (NaCl, Na2SO4 and (NH4)2SO4) at different pH values (3.0, 4.03, 6.5, 8.7 and 10.0) and salt concentrations (0.05, 0.1, 0.2, 0.3 and 0.5 mol/l). Solubility data of both egg products showed a distinct behaviour for each type of salt. A 4th-order polynomial model fitted the solubility data with R2 values higher than 0.83. It was observed the increase of the density as the salt concentration increase. The model used for density data correlation shown R2 values higher than 0.94. 相似文献
17.
Minimum inhibitory concentration (MIC) studies were conducted to observe synergistiC., antagonistic or additive effects produced by combinations of butylparaben, ethanol, potassium sorbate and sodium metabisulfite against growth of two Saccharomyces cerevisiae strains (Montrachet 522 and NCSU 76) in yeast nitrogen base-glucose broth at pH 3.30. Results suggested antagonistic effects between SO2/sorbate, SO3/butylparaben and butylparaben-ethanol. Additive effects were observed between ethanol/sorbate, ethanol/SO2, and butylparaben/sorbate. No synergistic effects were detected. NCSU 76 had higher MICs than Montrachet 522 for all individual antimicrobial agents indicating greater resistance to these compounds. On an individual molar basis, MIC results indicated butylparaben was more inhibitory than the other antimicrobial agents alone. 相似文献
18.
Sugar cane (Saccharum spp.) is a forage crop widely used in animal feed because of its high dry matter (DM) production (25 to 40 t/ha) and high energy concentration. The ensiling of sugar cane often incurs problems with the growth of yeasts, which leads to high losses of DM throughout the fermentative process. The selection of specific inoculants for sugar cane silage can improve the quality of the silage. The present study aimed to select strains of lactic acid bacteria (LAB) isolated from sugar cane silage and to assess their effects when used as additives on the same type of silage. The LAB strains were inoculated into sugar cane broth to evaluate their production of metabolites. The selected strains produced higher concentrations of acetic and propionic acids and resulted in better silage characteristics, such as low yeast population, lower ethanol content, and lesser DM loss. These data confirmed that facultative heterofermentative strains are not good candidates for sugar cane silage inoculation and may even worsen the quality of the silage fermentation by increasing DM losses throughout the process. Lactobacillus hilgardii strains UFLA SIL51 and UFLA SIL52 resulted in silage with the best characteristics in relation to DM loss, low ethanol content, higher LAB population, and low butyric acid content. Strains UFLA SIL51 and SIL52 are recommended as starter cultures for sugar cane silage. 相似文献
19.
Morán-Marroquín GA Córdova J Valle-Rodríguez JO Estarrón-Espinosa M Díaz-Montaño DM 《International journal of food microbiology》2011,151(1):87-92
Knowledge of physiological behavior of indigenous tequila yeast used in fermentation process is still limited. Yeasts have significant impact on the productivity fermentation process as well as the sensorial characteristics of the alcoholic beverage. For these reasons a better knowledge of the physiological and metabolic features of these yeasts is required. The effects of dilution rate, nitrogen and phosphorus source addition and micro-aeration on growth, fermentation and synthesis of volatile compounds of two native Saccharomyces cerevisiae strains, cultured in continuous fed with Agave tequilana juice were studied. For S1 and S2 strains, maximal concentrations of biomass, ethanol, consumed sugars, alcohols and esters were obtained at 0.04 h−1. Those concentrations quickly decreased as D increased. For S. cerevisiae S1 cultures (at D = 0.08 h−1) supplemented with ammonium phosphate (AP) from 1 to 4 g/L, concentrations of residual sugars decreased from 29.42 to 17.60 g/L and ethanol increased from 29.63 to 40.08 g/L, respectively. The S1 culture supplemented with AP was then micro-aerated from 0 to 0.02 vvm, improving all the kinetics parameters: biomass, ethanol and glycerol concentrations increased from 5.66, 40.08 and 3.11 g/L to 8.04, 45.91 and 4.88 g/L; residual sugars decreased from 17.67 g/L to 4.48 g/L; and rates of productions of biomass and ethanol, and consumption of sugars increased from 0.45, 3.21 and 7.33 g/L·h to 0.64, 3.67 and 8.38 g/L·h, respectively. Concentrations of volatile compounds were also influenced by the micro-aeration rate. Ester and alcohol concentrations were higher, in none aerated and in aerated cultures respectively. 相似文献
20.
Susanne L. Jensen Nicole L. Umiker Nils Arneborg Charles G. Edwards 《Food microbiology》2009,26(8):915-921
Yeast isolates from commercial red wines were characterized with regards to tolerances to molecular SO2, ethanol, and temperature as well as synthesis of 4-ethyl-phenol/4-ethyl-guaiacol in grape juice or wine. Based on rDNA sequencing, nine of the 11 isolates belonged to Dekkera bruxellensis (B1a, B1b, B2a, E1, F1a, F3, I1a, N2, and P2) while the other two were Candida pararugosa (Q2) and Pichia guilliermondii (Q3). Strains B1b, Q2, and Q3 were much more resistant to molecular SO2 in comparison to the other strains of Dekkera. These strains were inoculated (103–104 cfu/ml) along with lower populations of Saccharomyces (<500 cfu/ml) into red grape juice and red wine incubated at two temperatures, 15 °C and 21 °C. Although Saccharomyces quickly dominated fermentations in grape juice, B1b and Q2 grew and eventually reached populations >105 cfu/ml. In wine, Q3 never entered logarithmic growth and quickly died in contrast to Q2 which survived >40 days after inoculation. B1b grew well in wine incubated at 21 °C while slower growth was observed at 15 °C. Neither Q2 nor Q3 produced 4-ethyl-phenol or 4-ethyl-guaiacol, unlike B1b. However, lower concentrations of volatile phenols were present in wine incubated at 15 °C compared to 21 °C. 相似文献