枸杞酒酿造预处理中不同灭菌方式对枸杞汁色泽的影响

以枸杞干果为原料制备枸杞汁用以发酵枸杞酒,研究了在不同灭菌方式处理下,类胡萝卜素、酚类物质的含量变化对枸杞汁色泽及褐变度的影响。实验采用高效液相色谱(HPLC)等方法测定了枸杞汁中类胡萝卜素及酚类物质的含量,并对灭菌前后枸杞汁主要色素物质变化与褐变度的影响程度进行了分析。结果表明,多元酚氧化缩合与类胡萝卜素降解是影响枸杞汁色泽加深、褐变指数增大的主要原因。     

不同酵母菌在枸杞酒酿造过程中对类胡萝卜素降解的影响

为探究不同酵母菌在枸杞酒发酵过程中对类胡萝卜素降解的影响,本实验选择了具有代表性的5株不同酵母菌进行枸杞酒发酵实验,采用高效液相色谱法(HPLC)对不同酵母发酵的枸杞酒中类胡萝卜素进行测定,比较发酵过程中枸杞酒中主要的3种类胡萝卜素:玉米黄素、玉米黄素双棕榈酸酯、β-胡萝卜素的变化,并以类胡萝卜素做唯一碳源,观察酵母是否能够利用自身的酶降解类胡萝卜素。结果表明:5株酵母菌自身均不能直接利用类胡萝卜素,但发酵体系中类胡萝卜素会受到酵母发酵环境的变化而发生不同程度的降解,且发酵环境的变化取决于代谢产物。酿酒酵母发酵力强、发酵彻底。相比发酵力弱的非酿酒酵母对类胡萝卜素影响较大,但随着发酵时间的延长,类胡萝卜素都不同程度的呈下降趋势。     

混菌发酵桑葚果酒工艺优化及其特性分析

为探究混菌发酵桑葚果酒的酿造工艺,通过单因素试验探究菌株、接种时间、接种体积比、发酵时间和发酵温度对桑葚果酒品质的影响,并以单因素试验为基础,设计响应面优化试验。结果表明,库德毕赤酵母K1最适与酿酒酵母配伍发酵。混菌发酵桑葚果酒的最优工艺：库德毕赤酵母（Pichia kudriavzevii）提前于酿酒酵母（Saccharomyces cerevisiae）24 h接入,发酵温度26℃、发酵时间14.5 d、酿酒酵母与库德毕赤酵母接种体积比为2.0∶1。在该条件下,发酵得到的桑葚果酒酒精度为8.53%vol,感官评分为90.10。利用顶空固相微萃取-气质联用法（headspace solidphase microextraction-mass spectrometry coupled with gas chromatography-mass spectrometry,HS-SPME-GC-MS）对混菌发酵的桑葚果酒和单菌发酵的桑葚果酒的挥发性香气成分进行解析,共检出27种挥发性香气物质。相较于单菌发酵的桑葚果酒,混菌发酵的桑葚果酒中酯类物质的种类和含量明显增加。     

响应面法优化柑橘枸杞复合果酒酿造工艺

为了丰富果酒产品的种类,提高其经济价值,该研究以柑橘、枸杞为原料,利用响应面试验设计优化柑橘枸杞复合果酒的酿造工艺。结果表明,柑橘枸杞复合果酒最优的发酵工艺条件为初始糖度27.8%、物料比（柑橘汁∶枸杞汁）1∶2、酿酒酵母（Saccharomyces cerevisiae）接种量4.7%及发酵温度23.2 ℃;在此条件下可获得色泽亮黄透明、果香与酒香和谐、酒体丰满圆润的柑橘枸杞复合果酒,其感官评分为90.8分,酒精度为6.9%vol。     

采用HS-GC-MS法对枸杞汁发酵前后香气成分的比较分析

采用顶空固相微萃取（HS-SPME）法提取枸杞汁和枸杞酒样品中的挥发性成分,采用气相色谱质谱联用技术（GC-MS）对其中的香气化合物进行鉴定,并对二者香气组成和相对含量进行对比。结果表明,枸杞汁和枸杞酒中香气种类和组成具有明显差异,在枸杞汁和枸杞酒中分别检测出31个和58个峰,鉴定出13种和32种化合物。枸杞汁经过发酵,其风味物质的种类和含量得到增加。     

混菌发酵对‘123’苹果酒香气成分的影响

选用葡萄汁有孢汉逊酵母（Hanseniaspora uvarum）与卡利比克迈耶氏酵母（Meyerozyma caribbica）两种非酿酒酵母,按照不同菌株与接种顺序,分别与酿酒酵母（Saccharomyces cerevisiae）混合发酵（1∶1）制备‘123’苹果酒;以单菌发酵为对照,分析发酵过程中酵母生长变化、理化指标、香气成分和感官品质。结果表明,非酿酒酵母数量在顺序接种发酵过程中稳定在106～107数量级;与单菌对照组相比,混菌发酵组乙醇含量降低了0.49%vol～1.6%vol,挥发酸增加了0.02～0.11 g/L。先接种有孢汉逊酵母48 h后再接种酿酒酵母混菌发酵酒样（HS2）发酵结束时酒样挥发性香气物质总量达到最高（9 302.20μg/L）,其中品种香气较单菌发酵增加了63.4%。2,4-二叔丁基苯酚、正辛醇、乙酸异戊酯、己酸乙酯、辛酸乙酯等为HS2酒样的特征香气物质（OAV>1）,在感官上为‘123’苹果酒增加了果香与花香。因此,先接种有孢汉逊酵母再接种酿酒酵母（1∶1）混菌发酵方案适合应用于‘123’苹果酒酿造。     

黑果花楸枸杞混酿酒酿造工艺研究

以黑果花楸和枸杞为原料制作混酿酒,研究其发酵工艺条件。采用单因素试验、正交试验对黑果花楸和枸杞汁混合比例、原料初始pH值、发酵温度、酵母接种量进行优化。结果表明,黑果花楸枸杞混酿酒最佳工艺条件为：黑果花楸和枸杞汁混合比例1∶1(mL∶mL),调节原料初始pH值至3.6,控制发酵温度为18℃,酵母接种量为0.08%。在此工艺条件下,黑果花楸枸杞混酿酒感官评分为85分,酒精度可以达到11.8%vol,酒体呈紫红色,具有黑果花楸典型性香气,口感厚实、饱满。     

枸杞酒酿酒酵母的选育及其产香性能分析

酿酒酵母对酒的风味物质代谢具有重要作用。为获得适合枸杞酒发酵的酿酒酵母,该研究从枸杞汁自然发酵液和枸杞果表面筛选获得发酵性能优良的酿酒酵母11株。以市售酵母RV171、DV10、安琪SY和安琪RW作为对照,基于不同菌株发酵枸杞酒的理化性质和感官评价的差异,获得了酿酒酵母出发菌株Saccharomyces cerevisiae M-23。通过常压室温等离子体(atmospheric and room temperature plasma, ARTP)对酿酒酵母M-23进行诱变,结合高通量筛选(high-throughput screening, HTS)技术,最终选育出酿酒酵母菌株M-23-7-14。采用气相色谱-质谱法对自酿枸杞酒和2种市售枸杞酒(健康快车、金色传杞)中的主要挥发性化合物进行定性和定量研究,并结合气味活性值(odor activity value, OAV)分析,评价不同枸杞酒的香气特征。结果表明,选育的酿酒酵母与市售酿酒酵母在发酵枸杞酒的基本理化指标上无显著差异,其中,选育获得的M-23-7-14与出发菌株M-23相比,枸杞酒的主要风味物质相对总量提高了37.0%,并...     

枸杞酒发酵主要代谢产物对类胡萝卜素降解的影响

以鲜果枸杞为原料接种酵母菌发酵枸杞酒,采用高效液相色谱、气相色谱测定分析代谢产物中含量较多的醇类、酯类、羧酸类、醛酮类物质,以及枸杞酒发酵前后类胡萝卜素的含量变化,以测定的以上代谢产物含量为参数,建立模拟实验,对照分析各类代谢产物含量对类胡萝卜素含量的影响,确定在枸杞酒中影响类胡萝卜素降解的最主要因素。结果表明:羧酸类化合物是影响类胡萝卜素降解的主要因素,其次为醛酮类物质,影响最小的是酯类及醇类物质。     

不同工艺处理对野生猕猴桃酒品质的影响

分别对野生猕猴桃进行清汁、混汁和带皮发酵处理,采用顶空固相微萃取技术对不同酿造工艺野生猕猴桃酒的香气进行富集,用气相色谱-质谱联用技术对其进行定性定量分析,结合酒的基本理化指标和感官评价比较不同工艺处理野生猕猴桃酒的品质。结果表明：混汁发酵和带皮发酵可降低猕猴桃酒的总酸及挥发酸质量浓度,提高pH值,减少VC损失;带皮发酵的香气物质总量显著高于清汁和混汁发酵（P＜0.05）,且酒中的酯类、萜烯类、酮类物质质量浓度相对较高,但酸类物质质量浓度显著降低（P＜0.05）;不同工艺处理酒中特征香气有所差异,其感官香气也各具特色;带皮发酵酒的香气评分较高,猕猴桃品质特征香气突出;且在口感质量、口感浓度、口感纯正度、香气质量、香气浓度、香气纯正度及整体平衡性方面均优于清汁发酵和混汁发酵。因此,带皮发酵工艺可一定程度提高野生猕猴桃酒的品质。     

Effects of mediums on fermentation behaviour and aroma composition in pure and mixed culture of Saccharomyces cerevisiae with Torulaspora delbrueckii

The nutrient status and composition in mediums have a significant effect on yeast metabolism and phenotypic characteristics in wine fermentation. In this study, the effects of three frequently used mediums, including synthetic grape juice (SGJ), grape juice without grape pericarp and seeds (GJ) and grape must with grape pericarp and seeds (GMPS), on yeast fermentation behaviour and aroma compounds produced by pure and mixed culture of Saccharomyces cerevisiae T73 with Torulaspora delbrueckii TD20 were investigated after alcoholic fermentation. The results showed that high fermentation activities and cell population were always found in GJ medium irrespective of inoculated approach. More esters and higher alcohols were produced in GMPS medium fermented by pure S. cerevisiae, while SGJ medium had increased levels of fatty acids. Consistent with previous literatures, the mixed fermentation of T. delbrueckii and S. cerevisiae produced more acetate esters and fatty acids than the pure culture of S. cerevisiae, while this enological trait was only found in SGJ and GJ, not in GMPS. Our results highlighted that more attention should be paid to the fermentation medium when evaluating the enological and aromatic properties of selected yeasts used in industrial winemaking. In this regard, the combined use of GJ and GMPS medium might be a suitable choice.     

冰梨酒酿酒酵母的筛选

以鸭梨为原料,榨汁后经冷冻浓缩制成浓缩梨汁（即冰梨汁）,接入酿酒酵母（Saccharomyces cerevisiae）,在15 ℃下进行低温酒精发酵酿制成冰梨酒。通过比较8株酿酒酵母的发酵性能,及其所酿冰梨酒的理化指标、有机酸含量和感官品质,最终确定酿酒酵母R2为酿制冰梨酒的适宜菌种。该酵母生长繁殖快、降糖和产酒精能力强、发酵性能优良;酿出的冰梨酒酒香和谐,果香纯正,口感甜美醇厚、柔和爽口,具有冰梨酒特有的风味。     

枸杞酒发酵菌种的筛选及其香气分析

为筛选一株适合枸杞酒生产的酵母菌,考察活性干酵母K1、DSM、BY、DV10、EC118和安琪酵母的发酵能力,选择产酒精能力和产酒香乙酸异戊酯能力较强的安琪酵母、BY酵母和EC118酵母,进一步测定酒样中枸杞香气成分含量。采用气-质联用技术分析不同枸杞酒的香气成分,发现BY酵母的枸杞香气成分含量达到12.56mg/L,是安琪酵母和EC118酵母的1.44倍和1.91倍。综合考虑发酵能力和酒样的枸杞香气成分含量,选择BY酵母作为生产枸杞酒的菌种。     

Altered Patterns of Maltose and Glucose Fermentation by Brewing and Wine Yeasts Influenced by the Complexity of Nitrogen Source

Maltose and glucose fermentations by industrial brewing and wine yeasts strains were strongly affected by the structural complexity of the nitrogen source. In this study, four Saccharomyces cerevisiae strains, two brewing and two wine yeasts, were grown in a medium containing maltose or glucose supplemented with a nitrogen source varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids) and peptides (peptone). Diauxie was observed at low sugar concentration for brewing and wine strains, independent of nitrogen supplementation, and the type of sugar. At high sugar concentrations altered patterns of sugar fermentation were observed, and biomass accumulation and ethanol production depended on the nature of the nitrogen source and were different for brewing and wine strains. In maltose, high biomass production was observed under peptone and casamino acids for the brewing and wine strains, however efficient maltose utilization and high ethanol production was only observed in the presence of casamino acids for one brewing and one wine strain studied. Conversely, peptone and casamino acids induced higher biomass and ethanol production for the two other brewing and wine strains studied. With glucose, in general, peptone induced higher fermentation performance for all strains, and one brewing and wine strain produced the same amount of ethanol with peptone and casamino acids supplementation. Ammonium salts always induced poor yeast performance. The results described in this paper suggest that the complex nitrogen composition of the cultivation medium may create conditions resembling those responsible for inducing sluggish/stuck fermentation, and indicate that the kind and concentration of sugar, the complexity of nitrogen source and the yeast genetic background influence optimal industrial yeast fermentation performance.     

Screening of native S. cerevisiae strains in the production of Pajarete wine: a tradition of Atacama Region,Chile

Pajarete is a Chilean wine with an appellation of origin. Although it has organoleptic properties, intensive utilization of Saccharomyces cerevisiae commercial yeast through the years has presumably produced the loss of native strains that may be associated with Pajarete oenologic uniqueness. In order to evaluate the effect of re-incorporation of indigenous strains into Pajarete winemaking, native S. cerevisiae strains were isolated and selected based on their properties shown during small and large laboratory scale fermentation, and then evaluated in industrial bioreactors. From an initial set of 312 isolates, a single native strain was selected based on taxonomy, fermentation performance, aroma, residual sugars, and production of alcohol for incorporation into market scale.     

木枣产香酵母的分离筛选和应用

为了解决枣酒残糖较高、缺少风味等共性问题,从红枣产区野生酵母中分离、筛选适宜的产香酵母并用于枣酒酿造。该研究从不同自然发酵时期的木枣中分离产香酵母菌,对其进行分子生物学鉴定,并采用顶空固相微萃取-气质联用（HS-SPME-GC-MS）技术分析其发酵枣汁的香气成分。结果表明,共分离出232株产香酵母菌株,筛选出一株产香特性最好的菌株Z228,被鉴定为季也蒙毕赤酵母（Meyerozyma guilliermondii）,其单独发酵枣汁酒精度为6.2%vol,酸度为1.6 g/L,香气浓,发酵枣汁中共测得46种香气成分,主要为醇类、酸类和酚类;菌株Z228与酿酒酵母（Saccharomyces cerevisiae）协同发酵,枣酒酒精度为13.3%vol,残糖含量为5.6%,香气清香明显、协调,香气成分有层次感。     

Modulation of grape wine flavor via the sequential inoculation of Williopsis saturnus and Saccharomyces cerevisiae

The effects of the inoculum ratio of Williopsis saturnus var. saturnus NCYC22 and Saccharomyces cerevisiae var. bayanus EC-1118 at 1:200 and 1:800 on the chemical and volatile compositions of grape wine were studied in sequential fermentation. The grape juice was first inoculated with Williopsis (W.) saturnus for 9 d; thereafter, Saccharomyces (S.) cerevisiae was inoculated to continue the fermentation until d 19. The cell population of W. saturnus disappeared by d 13, with S. cerevisiae dominating until the end of the fermentation in both inoculum ratios. The changes in yeast count, pH, total soluble solids, sugars, organic acids, and amino acids were similar between the two inoculum ratios. A range of volatile compounds was formed, including alcohols, esters, fatty acids, aldehydes, and terpenes. There were significant differences between both inoculum ratios for medium-chain fatty acids (C8, C10, and C12), ethyl esters of fatty acids of C6, C10, C12, and C14 as well as isoamyl octanoate, while other volatiles were statistically the same.     

樱桃酒酿造用产香酵母的筛选及其特征香气成分分析

为提升杏酒品质,该研究以西南地区特色凯特杏为原料,以感官品评作为评价指标,在单因素试验的基础上,采用响应面法优化杏酒的发酵条件。结果表明,杏酒最佳发酵条件为采用D254酵母,发酵温度25 ℃、杏浆与水体积比4.4∶1、酵母接种量1.2 g/L、初始糖度21 °Bx、发酵时间7 d。在此优化条件下,酿造的杏酒呈金黄色、澄清透明,杏果香和醇香协调,酒体柔和,典型性强,并测得其酒精度为12.27%vol,还原糖含量为5.12 g/L,总酸含量为8.87 g/L,感官评分为85.45分。通过气相色谱-质谱仪（GC-MS）共检测出29种风味物质,主要为醇类和酯类等。