产香酵母的分离鉴定及对不同原料酿造甜酒香气成分的影响

该研究从传统颗粒甜酒曲中筛选分离产香酵母菌,结合形态学观察及分子生物学技术鉴定分离菌株,采用顶空-气相色谱（HS-GC）法对筛选菌株产香能力进行分析,并考察产香酵母对不同原料酿造甜酒香气成分的影响。结果表明,共分离筛选出6株酵母,其中5株菌（编号为YRNN1～YRNN5）被鉴定为扣囊复膜酵母（Saccharomycopsis fibuligera）,1株菌（编号为YRJM）被鉴定为酿酒酵母（Saccharomyces cerevisiae）。菌株YRNN5发酵米汁产β-苯乙醇最高（22.98 mg/L）,将其作为甜酒增香菌株应用于不同原料酿造甜酒。甜酒香气成分分析结果表明,籼米甜酒的β-苯乙醇和乙酸苯乙酯含量分别为771.38 mg/L、2.90 mg/L,显著高于籼糯米甜酒（P＜0.05）,且籼米甜酒和籼糯米甜酒的酒精度分别为15.15%vol和12.80%vol。菌株YRNN5和籼米可以作为甜酒发酵的产香酵母和优良原料。     

嗜杀酿酒酵母对海南山兰甜酒发酵品质的影响

以海南坡稻山兰为主要原料,在传统手工酿造山兰甜酒的工艺基础上添加嗜杀酿酒酵母作为发酵剂能保持山兰甜酒原始的酒醇甘甜微苦风味,维持独特的米脂芳香。控制和净化发酵醪中的酵母品质,在发酵过程中保持酒味纯正,使糖化与发酵得到同步,发酵力得到加强,酒味更加醇厚。同时发酵环境得到净化,发酵时间缩短,生产效率提高。嗜杀酵母发酵剂令山兰甜酒出现苦味物质的时间提前,同时相对传统工艺生成较高浓度的高级醇,可采取定时移除酒液的方法解决。     

强化发酵和传统发酵对米发糕风味的影响

采用接种单一酵母菌(ZSM-001)进行强化发酵和传统发酵制作米发糕,通过气质联用分析米发糕中挥发性成分及氨基酸自动分析仪检测游离氨基酸的组成和含量,并结合质构、感官的测定,研究强化发酵和传统发酵对米发糕风味的影响.结果表明:传统发酵制得的米发糕含32种挥发性成分,以脂类化合物为主,占挥发性物质总量的79.16％,其呈味氨基酸总含量(1 981.79 mg/100 g)显著高于强化发酵制得的米发糕(505.66 mg/100 g),产生的酸味、甜味和苦味氨基酸对滋味贡献更大,尤其是新增的甜味氨基酸对滋味的贡献,赋予传统发酵制得的米发糕酸甜适宜的滋味.     

籼米甜酒的发酵动力学及工艺优化

以籼米为原料制作甜米酒,研究发酵条件对米酒品质的影响,建立米酒发酵的动力学模型,确定适宜的发酵条件,为籼米甜酒的生产及品质控制提供实验数据。结果表明,发酵温度、加曲量及发酵时间对籼米甜酒的感官、出汁率、糖度、酸度和酒度等感官品质有影响。建立的基于发酵条件的甜米酒品质的多项式数学模型具有较高拟合精度。经非线性规划求解得到的籼米甜酒的最适工艺条件为加曲量1.6%、30℃发酵3.5d,制作的甜米酒感官品质优良。     

甜米酒发酵工艺条件研究

以糯米为原料,选择安琪甜酒曲发酵制作甜米酒,通过单因素试验和正交设计试验,研究了影响甜米酒发酵工艺条件的关键 因素,探讨了发酵时间、料水比、接种量对甜米酒产品品质的影响。 结果表明,在发酵时间为42 h、料水比为1.0∶0.9（g∶mL）、接种量为 0.4%时,制得的甜米酒综合评分最高为98分,此时的甜米酒质地均匀、酒醪清澈、醇香浓郁,柔和爽口,具有独特的甜米酒风格。     

Characteristics of some traditional Vietnamese starch-based rice wine fermentation starters (men)

In the Mekong Delta region of South-Vietnam, wine from purple glutinous rice is particularly interesting because of its sherry-like taste and flavour and its attractive brown-red colour. It is manufactured at home or by small cottage industries, using traditional solid-state starters (Men). With the objective of improving the knowledge about the functionality of traditional Men, this study deals with the properties and composition of 29 samples of Vietnamese commercial rice wine starters. We selected 6 rice wine starters for their superior ability to liquefy cooked rice, high ethanol accumulation, and production of attractive flavour and colour in the resulting wine. Ethanol contents reached 12 g/100 ml, a sweet alcoholic fragrance was noticed and the wine colour varied from red to lightly brown. Total mould, yeast and bacteria counts in Men were 3.4-6.0, 5.8-7.2 and 2.6-6.2 log CFU/g of dry weight sample, respectively. A total of 119 microbial strains, comprising 53 moulds, 51 yeasts and 15 bacteria, was isolated. Mould isolates with excellent functionality were identified as Amylomyces rouxii, Amylomyces aff. rouxii (an atypical form of A. rouxii), Rhizopus oligosporus and Rhizopus oryzae. Yeast isolates with excellent fermentation properties were all identified as Saccharomyces cerevisiae; other, less functional isolates were identified as Candida glabrata and Pichia anomala.     

甜酒酿的发酵工艺及其稳定性研究

以糯米为原料,经浸泡、蒸饭、拌曲、糖化和发酵等工序,得到醇甜清爽、风味和营养具佳的糯米甜酒;通过L9(34)正交试验确定甜酒酿发酵最佳工艺参数:拌曲量0.2％、发酵温度30℃、发酵时间60h、并对糯米甜酒主要指标的稳定性进行了研究.     

黑米甜酒酿发酵工艺及主要指标变化规律的研究

以黑米为主要原料,通过接种酒曲进行甜酒酿发酵,采用正交试验对黑米甜酒酿的发酵工艺进行优化,同时考察发酵过程中还原糖、酒精度和pH值的变化情况.结果表明,酒曲添加量为0.6％,发酵温度为30℃,发酵时间为72h,产品口感醇香、质地均一,酒液清澈,具有独特的风味.     

机械化生产黄酒酵母菌性能的研究

针对“三边发酵“理论中黄酒酵母菌性能的要求,通过研究黄酒酵母在TTC培养基中的变色情况、发酵力情况、糖化酶糖液中酵母生长情况、酵母耐酒精度、酵母形态和产香、酵母醭生成情况、酵母起发速度、酵母巨大菌落形态、酵母死灭温度、酵母与杆菌在MRS液体培养基中共同生长和凝聚情况及在锥形瓶中发酵试验.从中筛选出2#和3#酵母菌株搭配使用,更加适宜于机械化黄酒中的大罐发酵.     

Isolation and identification of Lactobacillus and yeast species and their effect on the quality of fermented rice cakes

In this study, microbes were isolated from the rice slurry of a fermented rice cake to obtain lactic acid bacteria and yeast species. These species were identified using microbial physiology and gene sequence analyses. As the growth of the lactic acid bacterial strain R-2b and the yeast J-3a strains were found to be the best, a composite starter comprising these microbes was used for the preparation of fermented rice cakes. Based on single factor and orthogonal experiments, when the proportion of Lactobacillus plantarum, Saccharomyces cerevisiae, and Candida humilis was 1:3:6, the optimal fermentation conditions were addition of sugar and starter amounts of 20% and 6%, respectively, a fermentation temperature of 32 °C, and fermentation time of 8 h. The fermented rice cake with this optimum ratio had the most abundant volatile components and qualified physicochemical and microbial indexes. Additionally, the overall quality was better than that of commercially available products.     

黄酒中不产生物胺乳酸菌的筛选及应用

为筛选不产生物胺的乳酸菌菌株,对黄酒发酵醪液及米浆水中的微生物进行培养及与分离纯化,发现3株菌不具有氨基酸脱羧酶活性,但具有一定的生物胺降解能力。使用黄酒发酵液培养该3株菌,发现在2.50%Vol的黄酒培养液中,3株菌能正常生长;在8.80%Vol黄酒培养液中,菌株5-4和8-3生长能力明显弱于14-2-1;在15.70%Vol黄酒培养液中,3株菌均受到严重抑制。菌株14-2-1生长速率最快,繁殖最旺,经鉴定为植物乳杆菌,同时菌株产酸能力较强,产酸速率也较快,表现出一定的优越性,应用于黄酒酿造中,能有效降低黄酒中生物胺的含量。     

酒曲中产凝乳酶微生物菌株的分离筛选及鉴定

针对酒曲中的微生物进行分离纯化,得到11株细菌和2株真菌,并采用酪蛋白平板法和Arima时间法筛选出了1株产凝乳酶的细菌菌株编号为LB-51。通过形态学观察、生理生化实验和16S rDNA序列分析鉴定该菌株为解淀粉芽孢杆菌,将该产凝乳酶菌株命名为解淀粉芽孢杆菌GSBa-1。该菌株在液体LB培养基中发酵72 h产凝乳酶的凝乳活力为(431.53±15.89)SU/mL,蛋白水解活力为(5.05±0.59)U/mL,所产凝乳酶凝乳活力高而蛋白水解活力低,凝乳酶粗酶单位酶活力为1.54×10~5SU/g。解淀粉芽孢杆菌GSBa-1是分离筛选自酒曲中的一株高产凝乳酶细菌,因此其来源安全,可作为工业化候选菌株进一步研究开发。     

六粮风味米酒工艺研究

以玉米、大米、小米、黑米、糯米、糯玉米6种米为原料,以米根霉和酿酒活性干酵母为糖化发酵剂,通过单因素试验对6种淀粉质原料米酒酿造用麸曲和酒曲的种类、比例及接种量、发酵温度、发酵时间等进行研究,再采用正交试验优选出六粮风味米酒发酵的最佳工艺参数。结果表明:麸曲与酒曲最佳质量比为1∶1,加曲量为0.6%,30℃条件下发酵48 h;玉米∶大米∶小米∶黑米∶糯米∶糯玉米的质量比为1∶1∶1∶2∶2∶2。此时的米酒质量最佳,酒质地均匀、酒醪清澈、醇香浓郁,柔和爽口,具有独特的甜米酒风味。     

紫红曲霉与酿酒酵母共发酵对红曲甜米酒风味的影响

研究紫红曲霉和酿酒酵母在红曲甜米酒发酵过程中风味物质形成的作用。利用紫红曲霉和酿酒酵母以不同比例复配进行甜米酒发酵,监测微生物、有机酸和挥发性香气成分的动态变化。结果表明,以发酵12 h为分界点,酵母菌先增加后减少,而红曲菌则同步呈先减少后增加的趋势;添加红曲菌能够显著促进酵母菌增殖。发酵过程中,酒样的糖度不断降低,酒精度不断增加,发酵36 h后有机酸(乳酸、乙酸、柠檬酸、酒石酸)含量迅速增加;随着红曲菌添加量的提高,糖度减少,酒精和有机酸含量均显著增加。发酵过程共检出47种挥发性组分,包括6种醇类、14种酸类、12种酯类、8种醚类、4种醛酮类、2种醌类和1种酚类,其中高级醇类(苯乙醇、香草醇、异丁醇)和酯类(对羟基扁桃酸乙酯)相对含量较高;酸类含量随发酵时间的延长不断减少,而醇类、酯类和醚类含量则不断增加;添加红曲菌使酯类在发酵前期迅速增加,显著提高其含量。综上所述,添加红曲菌共发酵,促进了酿酒酵母增殖,显著增加了有机酸和酯类等挥发性组分的种类和含量,对甜米酒风味物质的丰富具有重要贡献。     

紫薯清酒的制备研究

以紫薯和大米为原料,日本清酒曲霉为糖化菌种,液体三级培养法培养酒母,采用分批投料方式进行糖化发酵,研究紫薯清酒生产工艺。按该研究工艺酿制成的紫薯清酒酒精度为14%vol,酸度为3.14 g/L,总酯为0.96 g/L,固形物为22.28 g/L,还原糖为4.72 g/L。(晓文)     

蛹虫草甜米酒的酿造工艺研究

以蛹虫草大米为原料,酿造蛹虫草甜米酒。通过单因素和正交试验,对蛹虫草甜米酒的酿造工艺进行优化。结果表明,蛹虫草甜米酒的最佳酿造工艺条件为：甜酒曲接种量为1.5%,料液比为1∶3.0（g∶mL）,发酵温度28 ℃,发酵时间为3 d。在此工艺条件下,蛹虫草甜酒中虫草总糖含量为10.03 g/100 mL,虫草素含量1.24 mg/100 mL,酒精度1.2%vol,感官评分95分。此最佳工艺酿造的蛹虫草甜米酒呈现淡黄色,酒液澄清透明,复合香气协调浓郁,口感甜爽,余味绵长,同时具有较高的营养价值。     

米发糕的风味形成及特征分析

以丝苗米为原料,接种酵母菌发酵制作米发糕,对不同操作阶段风味物质进行测定,研究米发糕的风味形成及特征。结果表明,发酵和蒸制产生了米发糕特殊的滋味和挥发性气味物质,呈味游离氨基酸主要是米发糕蒸制过程中蛋白质的热降解所产生的,其中以苦味氨基酸比例最大,其次依次为甜味和鲜味氨基酸。发酵过程中产生了大量挥发性物质,蒸制过程进一步产生了以烷烃为主,兼有较多的醇、酸、酚、酮等挥发性物质,从而形成了米发糕特定的气味。米发糕的滋味物质主要在热降解过程中形成,而气味物质则与微生物降解和热降解有关。     

基于安琪混合酒曲的糯米酒新工艺研究

以安琪混合酒曲为发酵剂,对糯米酒的酿酒新工艺进行探究。以发酵酒液的酒精度、总酸、外观糖度、感官评分为评价指标,探究发酵时间、发酵温度、料液比、发酵剂添加量对酿造米酒的影响,在此基础上进行正交试验确定糯米酒的最佳酿造工艺。结果表明,发酵工艺条件为安琪混合酒曲（安琪甜酒曲:安琪纯种活性干酵母为4:1）添加量0.625%,料液比1.0:1.6（g:mL）,发酵温度30 ℃,发酵时间8 d。在此最佳工艺条件下,糯米酒的感官评分为92分,酒精度12.2%vol,外观糖度12.8%,总酸3.50 g/L。糯米酒酸甜适中,口感醇厚,具有独特的芳香。     

发酵法提取燕麦β-葡聚糖的初步探索

研究了发酵法对提取燕麦麸皮中的β-葡聚糖的影响,比较了发酵液中β-葡聚糖的含量。结果显示,4种酵母菌发酵后发酵液中β-葡聚糖含量都比未经过发酵的燕麦麸培养液中β-葡聚糖含量明显增加。采用酵母发酵的方法提取燕麦β-葡聚糖的最优发酵条件:发酵培养基在灭菌前加蛋白酶、淀粉酶和糖化酶共同处理,所用菌种为黄酒酵母,发酵时间控制在48h;摇床参数为170r/min,28℃。     

Volatile composition of partially fermented wines elaborated from sun dried Pedro Ximénez grapes

In this work, we used a cell immobilisation system consisting of Penicillium chrysogenum fungi (GRAS) bound to the osmotolerant yeast strains Saccharomyces cerevisiae X4 and X5 for the partial fermentation of raisin musts. The resulting wines were compared with others obtained by partial fermentation of musts with free yeasts and with a traditionally produced sweet wine (i.e. without fermentation of the must). The analysis of volatile compounds grouped by aroma series showed the partially fermented musts had a more complex aroma than the traditional wine. Specially prominent among aroma series was that of ripe fruit, followed by the milky and chemical series. The volatiles with the greatest impact on wine aroma as assessed in terms of odour activity were ethyl hexanoate, ethyl octanoate, butyrolactone, isoamyl alcohols, acetaldehyde, ethyl acetate, 2,3-butanediol, acetoin and 2,3-butanedione. A cluster analysis according to the Ward method was performed to assess the similarity between the traditional sweet wine and those obtained by partial fermentation with free and immobilised yeasts revealed small differences between the wines obtained with free and immobilised yeasts, and marked differences between partially fermented and traditionally obtained sweet wine. The wines provided by immobilised yeasts were the most appreciated in the sensory analysis (especially those obtained with X4 yeasts).