耐高渗酵母选育及其在葡萄酒中的应用研究

高醇、高糖、高硫等条件会影响酵母菌的生物活性。为筛选出耐高酒精度、高糖度、高SO2浓度的葡萄酒酿造优良菌株,该实验采集葡萄酒糟、黄酒糟、酒醅,经过富集筛选分离纯化得到8株酵母菌,经高酒精度、高糖度、高SO2耐受试验后初步筛选出2株菌株,一株耐高糖,在含糖量60%条件下21.5 h仍可启动发酵;一株耐高酒精度,在酒精度20%vol条件下21.3 h仍可启动发酵;2株菌株均可在300 mg/L SO2条件下在6.7 h启动发酵。经生理生化试验初步鉴定两株菌分别为酿酒酵母（Saccharomyces cerevisiae）和膜醭毕赤氏酵母（Pichia membranefaciens）。在浓缩葡萄汁初始糖含量28%条件下接种酿酒酵母,高泡期补料至含糖量34%接种膜醭毕赤氏酵母,20 ℃发酵15 d,得到的葡萄酒酒精度为18.1%vol。     

Yeast starter cultures affecting wine fermentation and volatiles

The influence of the addition of different concentrated inocula of various strains of Saccahromyces cerevisiae to high sugar content must on both evolution of sugar concentration and the volatile composition of the wines were studied. Evolution of sugar content was characteristic of the yeast strain and one was incapable of finishing fermentation. Volatile compounds were analyzed by using fused silica capillary GC column. Application of cluster analysis to the data showed that differences in the volatile fraction are mainly due to the inoculated yeast strain, although concentration of higher alcohols increases directly as the inoculum concentration.     

不同发酵剂对红枣果酒发酵品质的影响

选取4种不同的发酵剂（帝伯仕LA DELICIEUSE活性干酵母（LA-D）、安琪酵母、清香型酒曲和薯曲）分别对红枣进行发酵,通过对感官评分、酒精度、色度以及发酵过程中营养成分含量变化和抗氧化活性等指标进行比较,筛选出一种性能较优的发酵剂。结果表明,LA-D酵母发酵酒的色泽透亮,为琥珀色,苦味较小,枣香味浓郁,感官评分达88.5分,酒精度为10.6%vol;在发酵第12天,VC含量为213.37 mg/100 mL、总黄酮含量为3.49 mg/mL、氨基酸态氮含量为933.3 mg/100 mL,均高于其他三种酵母发酵酒,总多酚含量为0.212 mg/mL,仅次于清香型酒曲发酵酒。枣酒的抗氧化性实验结果表明,在发酵末期,LA-D酵母发酵酒的还原力、羟基、超氧阴离子、DPPH自由基清除率分别为2.425、77.38%、88.75%、92.8%。通过以上实验,分析得出LA-D酵母是最适合红枣果酒发酵的酵母。     

Performance of wild Saccharomyces and Non-Saccharomyces yeasts as starter cultures in dough fermentation and bread making

The use of wild Saccharomyces and non-Saccharomyces yeasts might result in bread with different and attractive sensory characteristics. This study aimed to evaluate the performance of Saccharomyces and non-Saccharomyces yeasts as starter culture in dough fermentation to bread making and the physicochemical parameters and aromatic profile of bread. All 26 wild yeasts strains isolated from Brazilian Cerrado fruit and tree bark were osmotolerant, and 19.4% were able to ferment maltose. Candida tropicalis ART101.3 and Saccharomyces cerevisiae SC5952 had the best growth capacity under high concentrations of glucose and maltose. Also, they were resistant to lyophilisation. Kinetic parameters of bioreactor cultivations showed high cell growth and lower generation time with 10 g L⁻¹ maltose. Bread produced with C. tropicalis ART101.3 and the control bread had similar physicochemical properties and acceptance of consumers. Bread with S. cerevisiae SC5951 had a lower specific volume and a different colour than control bread; however, the consumers found no significant difference. More than 70% of the consumers demonstrated purchase intention of bread produced with both wild yeasts. The present study shows the potential of native Cerrado yeasts to be used and exploited in industrial processes and contributes to the diversification of bread starter cultures.     

Microbial ecology studies of spontaneous fermentation: starter culture selection for prickly pear wine production

Abstract: A procedure for designing starter cultures for fermentation is illustrated for prickly pear wine production. The illustration includes kinetic studies on inoculated and spontaneous fermentation, microorganism identification studies based on molecular biology tools, and microbial ecology studies, which led to the selection of strains that are capable of synthesizing alcohol and desirable volatile compounds. Results show that a mixed starter inoculum containing Pichia fermentans and Saccharomyces cerevisiae leads to a fermented product that contains 8.37% alcohol (v/v). The gas chromatography and mass spectrometry (GC‐MS) analysis shows the presence of 9 major volatile compounds (Isobutanol, Isopentanol, Ethyl acetate, Isoamyl acetate, Ethyl octanoate, Ethyl decanoate, Ethyl 9‐decanoate, β‐Phenylethyl acetate, and Phenylethyl alcohol) that have ethereal, fruity, aromatic notes that are considered to be essential for a fine wine flavor. These compounds harmonically synergize with the alcohol to produce a fermented product with a unique flavor and taste. Several assays using the mixed culture show that the process is stable, predictable, controllable, and reproducible. Moreover, the results show that a mixed culture leads to a broader range of aromatic products than that produced by a single, pure culture. Therefore, we conclude that combinations of Saccharomyces strains and non‐Saccharomyces strains can be used to obtain high‐quality fermented beverages from prickly pear juice.     

不同菌种对青稞酒发酵的影响

以青稞酒传统生产工艺为基础,研究了发酵过程中使用不同菌种对青稞酒感官品质和出酒率的影响。结果表明,以传统的青稞整粒固态发酵工艺,以单一菌种发酵生产的青稞酒产品其出酒率和产品感官品质几乎没有提高,而使用酿酒酵母和甜酒曲复合菌种,可以在保证产品观感质量的前提下相对于当地青稞酒生产工艺提高出酒率1倍以上。      

Lactobacillus reuteri CRL 1100 as starter culture for wheat dough fermentation

The effect of sucrose on the fermentation balance of Lactobacillus reuteri CRL 1100 and the invertase activity of this strain in wheat dough and culture medium (MRSs) was evaluated. The enzyme activity was dependent on the environmental pH releasing glucose and fructose from sucrose hydrolysis. Glucose was used as carbon source, while fructose was mainly used as electron acceptor to produce mannitol up to 10h of fermentation. Thereafter, fructose seemed to be metabolized by the heterofermentative pathway, which determined an increase in the concentration of acetate (6 mmol l(-1)), lactate (2 mmol l(-1)) and ethanol (1 mmol l(-1)) and the lack of mannitol formation after glucose depletion. The fermentation balance of Lb. reuteri CRL 1100 during the dough fermentation resulted in lower (63%) ethanol, higher (75%) acetate production and soluble carbohydrates concentrations, like MRSs cultures. This fermentation profile would be important to obtain an optimal growth of yeast and the optimal bread flavor and taste.     

Physicochemical properties of Korean rice wine (Makgeolli) fermented using yeasts isolated from Korean traditional nuruk,a starter culture

The applicability of Saccharomycopsis fibuligera CJN1020, Pichia jadinii CJN1287, and Saccharomyces cerevisiae CJN1514 isolated from Korean nuruk, a starter culture, for preparation makgeolli was investigated. These yeasts were suitable for preparation of both white rice makgeolli using a steam method and white rice-brown rice-wheat flour (WBW) makgeolli using a complex method. Upon physicochemical evaluation, there were no differences in the final ethanol concentrations between white rice makgeolli and WBW makgeolli. Differences in final ethanol yields occurred according to yeast species. Final ethanol yields using S. fibuligera and P. jadinii were 16 and 18% using S. cerevisiae. WBW makgeolli samples received higher sensory scores than white rice makgeolli for overall preference. GC/MS analysis revealed higher amounts of aromatic compounds in WBW makgeolli than in white rice makgeolli. The complex method was suitable for preparation of makgeolli using brown rice and wheat flour.     

不同酵母酿造霞多丽干白葡萄酒的发酵性能研究

选用5种商品酵母酿造霞多丽干白葡萄酒,对5种酵母的发酵性能进行比较,测定样品的理化指标和香气物质。结果表明,5种酵母酿造霞多丽干白葡萄酒的理化指标均符合国标,在发酵期的密度变化趋势基本一致,但发酵周期不同;结合固相微萃取和气质联用（GC-MS）检测技术,5种发酵的酒样中分别检出的香气物质33种、31种、36种、34种、29种,主要香气组分没有大的差别,只是在微量香气物质上有所区别。酵母CEC01对葡萄糖的利用率最高,其酿造霞多丽干白葡萄酒酒精度为12.9%vol,残糖含量为1.5 g/L,发酵周期短;检出的香气物质最多（36种）,并且酯类含量最高,占其香气物质总量的35.66%。     

梅鹿辄葡萄自然发酵酵母菌群研究

利用WL营养培养基对梅鹿辄葡萄自然发酵过程中分离到的98株酵母菌进行初步鉴定,进而对代表性的菌株进行5.8S rDNA-ITS区PCR产物的限制性内切酶酶切分析.结果表明,供试的98株酵母菌属于3属3个种,分别为酿酒酵母(Saccharomyces cerevisiae)、东方伊萨酵母(Issatchenkia orientalis)、克鲁维毕赤酵母(Pichia kluyver),3种酵母菌分别占分离自该葡萄品种总酵母菌株的80.61％、13.26％、6.13％.在自然发酵的初期和中期,酵母菌的比例因是否添加SO2而有所差异,但发酵末期均以S.cerevisiae为优势菌.     

Saccharomyces cerevisiae as a starter culture in Mycella

The potential use of Saccharomyces cerevisiae FB7 as an additional starter culture for the production of Mycella, a Danish Gorgonzola type cheese, was investigated. Two dairy productions of Mycella, each containing batches of experimental cheeses with S. cerevisiae added and reference cheeses without yeast added were carried out. For both experimental and reference cheeses, chemical analysis (pH, a(w), NaCl, water and fat content) were carried out during the ripening period, but no significant differences were found. The evolution of lactic acid bacteria was almost identical in both the experimental and reference cheeses and similar results were found for the number of yeast. S. cerevisiae FB7 was found to be predominant in the core of the experimental cheeses throughout the ripening period, while Debaryomyces hansenii dominated in the reference cheese and on the surface of the experimental cheeses. In the cheeses with S. cerevisiae FB7, an earlier sporulation and an improved growth of Penicillium roqueforti was observed compared to the reference cheeses. Furthermore, in the experimental cheese, synergistic interactions were also found in the aroma analysis, the degradation of casein and by the sensory analysis. The observed differences indicate a positive contribution to the overall quality of Mycella by S. cerevisiae FB7.     

7种酵母酿造摩尔多瓦葡萄酒的发酵特性比较

在常用的商业酵母中筛选一株酵母,应用于摩尔多瓦葡萄酒酿造,从而实现鲜食摩尔多瓦葡萄的增值。以摩尔多瓦葡萄为材料,选用VL1、F15、NS-D、P、HXD29、LE28、LD1015 7种酵母进行葡萄酒酿造试验,以自然发酵作为对照,对不同酵母发酵酒的总酸、总酚等理化性质进行检测和感官评价,比较不同酵母对摩尔多瓦葡萄酒理化性质及品质的影响。结果表明,酵母LD1015发酵的摩尔多瓦酒干浸物含量最高,为17.96 g/L;总糖含量为3.54 g/L,总酚含量为1.17 g/L,略低于酵母VL1、HXD29、LE28,感官评分最高,为91分。综合判定酵母LD1015具有较强的糖转化和干物质浸提的能力,有利于产出口感醇厚、香气馥郁的葡萄酒,是7种酵母中最适合鲜食葡萄摩尔多瓦酿酒的酵母菌种。     

杏酒酵母的筛选及发酵性能的研究

对16株野生酵母进行杏酒发酵试验,通过理化指标的测定和感官评价,筛选适合酿造杏酒的酵母.结果表明,酵母16、酵母06、酵母02是具有良好酿酒特性的菌种.其中酵母16发酵的杏酒感官质量最佳,其发酵的杏酒金黄清亮,具有优雅的果香与醇香,酒体饱满,酸甜适口;并且在杏汁中具有良好的适应能力,分别能在16％vol乙醇、600mg/L SO2、6％柠檬酸、70％含糖量的杏汁中发酵,在10℃时仍可发酵,在50℃时可以生长,为发酵杏酒的最佳菌株.     

Distribution of phenolic yeasts and production of phenolic off-flavors in wine fermentation

The activity of wine yeasts to decarboxylate ferulic and p-coumaric acids is one of their biological properties related to the production of phenolic off-flavors (POF) in wine-making. We examined POF productivity in 116 strains of wine yeast, 74 strains of wild yeast (Saccharomyces cerevisiae) and 23 strains of non-Saccharomyces yeast, and found that a majority of these yeasts were POF-producing strains. The frequency distribution of POF-producing strains was 81 to 95% in wine yeasts, 85 to 97% in wild yeasts and 78 to 83% in non-Saccharomyces yeasts based on the POF test with addition of ferulic and p-coumaric acids to grape juice medium. The Rhodotorula, Candida, Cryptococcus, Pichia, Hansenula, and Brettanomyces strains had high or moderate POF productivity among the 20 non-Saccharomyces species. The decomposition rate of ferulic acid correlated with POF production and the critical concentration of phenolic acid (free form) in grape must was estimated to be more than 10 mg/l. Segregation of POF phenotype and Southern blot analysis of phenolic wine yeasts suggest that POF production is controlled by the POF gene (PAD1). The results showed the frequent distribution of phenolic yeasts in the wine-making environment. These suggest the importance of controlling POF production by using wine yeast strains of low POF productivity. The grapes must be prepared by a suitable process to prevent the increase in phenolic acid content.     

甜酒曲生长特性研究及米酒生产工艺优化

对米酒生产中加曲量、糖化时间、加水比、糖化发酵温度、发酵时间等单因素进行分析,检测总糖、外观糖度、总酸、酒精度和凝乳酶。同时记录发酵液中霉菌、酵母菌和乳酸菌在不同条件下的总菌数,进一步详细了解甜酒曲中微生物在米酒发酵过程中的变化情况,为米酒工艺优化提供依据。通过统计软件Design expert7.1对L8(27)正交试验进行极差和方差分析,确定米酒生产最佳工艺组合:糖化发酵温度28℃、糖化时间48h、加曲量2.0%。     

喷雾干燥法制备冰酒发酵剂的研究

从四川藏区高原霞多丽冰葡萄渣中分离纯化出了一种菌株,经18S rDNA D1/D2序列鉴定为葡萄汁有孢汉逊酵母（Hanseniaspora uvarum）,并通过正交试验对保护剂的配方进行优化,单因素试验初步研究喷雾干燥的的条件。结果表明,喷雾干燥最佳保护剂的配方为脱脂奶粉7%,酵母浸粉5%,乳糖0.6%,黄原胶0.20%,得到的干菌粉中的活菌数为2.6×1010 CFU/g;确定喷雾干燥实验最适条件为进口温度120 ℃,进样流量20 mL/h,保护剂与菌泥比例4∶1（g∶L）,按上述条件得到的干菌粉的活菌数为2.4×108 CFU/g。     

利用WL营养培养基鉴定葡萄酒中的相关酵母菌

采用WL营养培养基对自然发酵前、中、后期出现的酵母菌进行了初步的分类鉴定。产膜的假丝酵母、葡萄汁有孢汉逊酵母及酿酒酵母在自然发酵初期占据主导地位,主要来自葡萄浆果表面;发酵中期主要为毕赤氏酵母;后期则全部为酵母属的酿酒酵母。WL营养培养基对于监测葡萄酒发酵过程中酵母菌群的变化十分有力,可以作为葡萄酒相关酵母鉴定的辅助手段。     

黄酒中制糖化发酵剂对原料质量要求

简叙了制糖化发酵剂对原料的基本要求和制酒曲酵母原料的种类、性质、择用、配料的例证.在此基础上提出了只有充分重视制酒曲、酵母的原料质量,才能提高黄酒酿造产量的品质和风味的观点.     

Occurrence of the killer character in yeasts associated with Spanish wine production

The occurrence of neutral, sensitive or killer phenotypes in 270 oenological yeast strains belonging to 18 species was studied. Strains were isolated from a total of 54 samples representing spontaneous fermentations at 11 wineries of the three Madrid viticultural areas (Arganda, Navalcarnero and San Martı́n de Valdeiglesias). The percentage of strains with the killer phenotype was 42·6% but this percentage varied during the fermentation: 18·8% in must, 50·0% in the middle and 58·8% by late fermentation. The highest frequency of the killer phenotype occurred in the species Saccharomyces cerevisiae (86·9%). Killer activity for this species was shown to result from toxins in the K₂ and K₃ groups.