干化葡萄酒生产中果胶酶和酵母的研究

介绍了干化葡萄酒生产过程中果胶酶和酵母的使用研究,根据不同果胶酶和不同酵母的对比试验结果表明,EX-V 果胶酶和 RC212 酵母用于干化葡萄酒的生产效果较好。     

Study on the Use of Pectinase and Yeast in the Production of Wine by Air Dry Grape

介绍了干化葡萄酒生产过程中果胶酶和酵母的使用研究。根据不同果胶酶和不同酵母的对比试验,结果表明,EX-V果胶酶和RC212酵母用于干化葡萄酒的生产效果较好。     

天然酵母菌株对赤霞珠葡萄酒香气构成的影响

以烟台赤霞珠葡萄为原料,用筛选的2株天然葡萄酒酵母菌株ZYFJQ、YQY和商品酵母RC212、D254单独或组合发酵生产干红葡萄酒。酒样常规理化指标分析表明,所有单菌株及组合发酵酒样的理化指标均符合葡萄酒国标要求。香气成分的GC-MS结果显示:RC212+D254+YQY菌株共发酵产生31种香气,香气种类最多,口感和谐。RC212+ZYFJQ组合发酵酒样在理化指标和香气协调性上较为突出。     

黑比诺葡萄接种发酵过程酵母菌的变化监控

采用WL营养琼脂培养基和Interdella指纹图谱分析以及UPGMA聚类分析,对接种工业酵母RC212的黑比诺葡萄酒发酵过程中分离的63株酵母进行种类区分与鉴定,并对其中的49株酿酒酵母单菌落进行菌株区分,以监控发酵过程中酵母菌的种类和动态变化,明确工业酵母是否主导发酵过程,探讨野生酿酒酵母与工业酵母之间的竞争性,为葡萄酒发酵过程中的微生物控制提供依据.结果表明,接种发酵过程中共分离得4种不同培养类型的酵母菌,分别是葡萄汁有孢汉逊酵母(Hanseniaspora uvarum)、美极梅奇酵母(Metschnikowia pulcherrima)、红冬孢酵母(Rhodotorula mucilaqinosa)和酿酒酵母(Soccharomyces cerevisiae).用Interdelta指纹图谱将酿酒酵母区分为3种基因型,包括2种野生酿酒酵母和已接种的工业酵母RC212.工业酵母在发酵初、中、后期分别占酿酒酵母的6.25%、18.75%、100%.工业酵母在发酵末期才成为发酵优势菌,野生酿酒酵母在发酵初期和中期都位据优势地位,表现出很强的竞争力.     

不同酵母菌株共发酵对葡萄酒香气成分的影响

以烟台蛇龙珠葡萄为原料,用筛选的2株天然葡萄酒酵母菌株ZYFJQ、YQY和商品酵母RC212、D254组合发酵生产干红葡萄酒。酒样理化指标及香气成分的GC-MS分析表明,所有单菌株及组合发酵酒样的理化指标均符合葡萄酒国标要求。RC212＋D254＋YQY共发酵产生38种香气,香气种类最多,醇香浓郁,口感柔和。D254＋ZYFJQ是生产烟台产地葡萄酒的优良组合,其发酵酒在理化指标和香气协调性上较为突出。     

白起泡葡萄酒发酵工艺的优化

以霞多丽葡萄为原料研制起泡葡萄酒,从原料产地的选择、果胶酶的选择、酵母的选择、氧化的控制、二次发酵酵母的选择和二次发酵温度的控制几个方面进行试验。试验得出白葡萄酒发酵工艺的参数为选用在8月下旬、9月上旬采收的宁夏芦花台产区的霞多丽葡萄,17℃～18℃下用法国L2型果胶酶澄清15 h,酒精发酵前添加复合抗氧化剂,选用法国M2酵母进行酒精发酵,17℃下用法国X1酵母进行二次发酵。在此条件下酿造的白起泡葡萄酒呈禾杆黄色,色泽鲜明,具有浓郁的热带水果香气和优雅的酒香,纯正细腻,酒体醇厚,清爽适口,具杀口力。     

戴尔有孢圆酵母对葡萄酒香气的影响

以新疆天山北麓产区和山东乳山产区赤霞珠葡萄为原料,分别选用酿酒酵母、戴尔有孢圆酵母单独发酵以及二者混合发酵,发酵结束后测定葡萄酒的各项理化指标以及挥发性化合物含量。结果表明：2个产地赤霞珠葡萄酒共检测出60种与酵母代谢相关的挥发性化合物,其中醇类23种、酯类26种、酸类8种和酮类3种,不同酵母菌发酵的葡萄酒中的香气成分及含量差异明显;戴尔有孢圆酵母单独发酵产生的醇类、酯类和酸类含量都较高,而与酿酒酵母混合发酵则降低了挥发酸的含量;本实验中戴尔有孢圆酵母明显提高了赤霞珠葡萄酒中乙基酯类的含量,特别是辛酸乙酯、癸酸乙酯和月桂酸乙酯等脂肪酸乙酯,增加了葡萄酒中的果香味;对于原料来自不同产地的葡萄酒,戴尔有孢圆酵母与酿酒酵母混合发酵均可以增强其发酵香气,提高葡萄酒香气的复杂性。     

不同酵母发酵的火龙果酒抗氧化活性及颜色变化

研究4种不同酵母发酵的火龙果酒在发酵过程中总酚、甜菜苷、抗氧化活性和颜色的变化规律。结果表明,在发酵过程中,4种酵母发酵火龙果酒的总酚、甜菜苷含量均呈下降趋势;L*值、a*值均升高,b*值降低。酵母RC212发酵的火龙果酒的多酚含量最高为272.5 μg/mL,其对DPPH自由基清除率IC50最低为22.98%;酵母R2发酵的火龙果酒的羟自由基清除率、总还原力IC50最低,分别为8.84%、28.52%,并且甜菜苷含量最高为581.4 mg/L。酵母RC212与酵母R2发酵的火龙果酒在抗氧化物质含量、抗氧化活性及红色素稳定性方面均优于酵母DV10与酵母D254发酵的火龙果酒。     

甘肃产地葡萄酒的酿造研究

用分离的3株天然葡萄酒酵母菌株GS13F、GS38A、HYHP3C和商品酵母RC212组合发酵生产原产地干红葡萄酒,葡萄原料赤霞珠和蛇龙珠采自武威.酒样理化指标及香气成分的CJC-MS分析结果表明,以天然酵母菌株发酵的酒样,理化指标均符合葡萄酒国标要求,菌株GS38A发酵酒的酒度(7.2%)与RC212(8.0%)接近,而菌株GS13F的发酵香种类多、比例协调,主要有乙酸异戊酯(27.54%)、乙酸苯乙酯(15.67%)和2-苯乙醇(9.85%).菌株配伍发酵后GS13F产香特性与GS38A、RC212高酒度特性优势互补,且发酵香种类和含量均增加,酒体骨架更为丰厚协调,可用于甘肃产地葡萄酒的生产.     

红葡萄酒酿酒酵母的分离筛选研究

流行性病学研究发现适量的饮用红葡萄酒可以降低心血管疾病、动脉粥样硬化和癌症等多种疾病的发病率。在酿造设备、生态条件与葡萄品种、工艺条件三个因素相对稳定的情况下,酵母菌的酿造学特性直接影响葡萄酒的质量和风格。山东省烟台地区是我国葡萄酒的主产区之一,历史悠久,酒厂众多,因而选育适合本产区葡萄特性、土壤特点、地域特性的优良酵母并酿出风格独特、具有品种典型性的葡萄酒显得尤为重要。本研究从葡萄、葡萄园土壤分离获得32株酵母菌株,通过杜氏管发酵、耐酒精、耐糖、耐酸、耐SO2和葡萄酒发酵试验,筛选出一株优良葡萄酒酿酒酵母QY-29。QY-29菌株发酵的葡萄酒具有酒体澄清、透明、果香浓郁、酒体丰满等特点,将进一步提高当地葡萄酒的市场竞争力和商业价值。     

玫瑰蜜葡萄酿造中果胶酶的优选及应用

通过果胶酶对红葡萄酒的各项指标影响的研究,筛选出适合于云南高原产区玫瑰蜜品种的果胶酶种类,结果表明,在试验的Lafazym Press(简称LP) Lafase Clarification(简称LC)、Rapidase EX color(简称Rap)、BEC、Optivin RED 6284(简称6284)、维诺红6种...     

Brewing with Rice Malt — A Gluten‐free Alternative

The preparation of beer‐like beverages with rice malt as the only raw material is reported. Several tests were performed on a laboratory scale and in a 25 L‐capacity pilot plant. Both the decoction and the infusion procedure were tested; malt and water were mixed in a ratio 1:3.5 for both methods and the mash was brewed without adding exogenous enzymes. The obtained worts were fermented using bottom fermenting yeasts, while “beers” were re‐fermented utilizing top fermenting yeasts and adding either sterile wort or sugar. A maximum ethanol of 4.5% vol. was obtained after the primary fermentation from an initial wort with an original gravity of 11.8°Plato. All parameters of the beer were found to be acceptable using a standard beer analysis. Owing to a suitable hop addition, an aroma very similar to that of a normal beer was obtained.     

野木瓜酵母菌株抗性及发酵特性评价

以从野木瓜自然发酵过程中筛选出的8株发酵力强、产香好的酵母菌,对其进行抗性（温度耐受性、葡萄糖耐受性、酒精耐受性等）评价。供试菌株中,在NaCl浓度为140 g/L时,有4株菌仍可生长发酵并具耐高渗性,可用于高盐环境发酵中;菌株B7-2、C-4、BL-5的耐高温性较好,在55℃时仍可生长,可用于工业生产的高温环境;所有供试菌株都有很好的SO2耐受性,筛选的5株优良酵母模拟酒精发酵实验中,菌株C-4、B1-3产酒精度高于商品酵母RC212,可以作为优良酵母进一步开发利用。菌株B7-2产酒精度为0,但产香很好,可作为产香酵母在发酵过程中适量添加以增加香味,或者用于面包和无醇饮料的开发。     

利用淀粉糖化醪进行酒精连续发酵的研究

从多株酒精酵母菌株中筛选出S.cerevisiae KG作为连续发酵菌株,在酒精连续发酵过程中使用具有细胞循环的双罐系统。淀粉经酸酶复合糖化,然后送入酒精连续发酵系统,酒精生产强度可达到28.5(g/l.hr)。     

Naturally fermented black olives: Effect on cell wall polysaccharides and on enzyme activities of Taggiasca and Conservolea varieties

Black olives of Taggiasca (Ta) and Conservolea (Co) varieties were processed according to the Greek style method in order to investigate the effect of this type of table olive processing on cell wall composition. Naturally black processing involves the storage in brine of fully ripe olives for several months, allowing a spontaneous fermentation by a mixed flora followed by fermentation by the lactic acid bacteria and yeasts. The smaller fruits of Ta variety are richer in pectic polysaccharides, accounting for half of total cell wall polysaccharides (12 mg/fruit), whereas in Co they accounted for one third (23 mg/fruit). Fresh Co olives had higher proportion of glucuronoxylans and xyloglucans (33%), whereas these polysaccharides accounted for 22% in Ta. The processing did not cause significant variations in the cell wall polysaccharide composition of Ta fruits, although pectic polysaccharides became more soluble in aqueous solutions. Conversely, processed Co olives had slightly higher amounts of galacturonan-rich pectic polysaccharides than the unprocessed fruits, suggesting that the long stage in brine might have contributed to the stabilisation and/or the biosynthesis of new polysaccharides. The changes caused by processing on cell wall polysaccharides appear to be closely related to the activity and availability of cell wall degrading enzymes.     

Behaviour of Escherichia coli O157:H7 during the fermentation of Datta and Awaze, traditional Ethiopian fermented condiments, and during product storage at ambient and refrigeration temperatures

The survival of E. coli O157:H7 in fermenting foods and its prolonged survival in refrigerated fermented foods is documented. This prompted the study to evaluate survival of E. coli O157:H7 during the fermentation of Datta and Awaze, traditional Ethiopian condiments. Datta was prepared by wet milling a variety of spices along with green or red chilli and fermenting it by lactic acid bacteria. Awaze is a slurry made of red pepper, garlic and ginger to which various other spices were added and fermented by lactic acid bacteria (LAB) and yeasts. The Datta or Awaze slurry was separately inoculated with three strains of E. coli O157:H7 and the fermentation was allowed to proceed at ambient (20–25°C) temperatures for 7 days. When fermenting Datta or Awaze was initially inoculated at low inoculum level (3 log cfu/g), the test strains were not recovered after 24 h of fermentation. At higher initial inoculum level (6 log cfu/g), however, counts of the test strains in Datta at day 7 were less by about 1.5 log unit than the initial inoculum level. In fermenting Awaze, all test strains were completely eliminated in 7 days. The pH of the fermenting green and red Datta was reduced from 5.2 to 4.4 and that of Awaze dropped from 4.9 to 3.8 during this time. In another experiment, the fermented products were separately inoculated with the E. coli O157:H7 test strains at levels of 6 log cfu/g and incubated at ambient and refrigeration (4°C) temperatures for 7 days. In fermented Datta, two of the three strains were not recovered by enrichment after 6 days of storage at ambient temperatures. In fermented Awaze, all strains were below countable levels at day 5, but could still be recovered by enrichment at day 7. At refrigeration storage, counts of the test strains in Datta and Awaze products were <3 log cfu/g at day 7. The inhibition of our E. coli O157:H7 test strains in Datta and Awaze may be due to the antimicrobial activity of spices and other metabolites produced by LAB which may be effective at low pH.     

靖州杨梅果酒发酵菌种筛选、鉴定及发酵性能研究

以不同杨梅园杨梅鲜果、杨梅叶和果园土壤为原料,共分离得到172株酵母菌。采用显色法、杜氏管法、糖发酵法和杨梅酒发酵法进行四级筛选,获得3株综合性能优良的菌株;经形态学、分子生物学鉴定为酿酒酵母(Saccharomyces cerevisiae)RY1、仙人掌有孢汉逊酵母(Hanseniaspora opuntiae)DY5与有孢汉逊酵母(Hanseniaspora pseudoquilliermondii)JW14。通过发酵性能研究发现,3株酵母均能耐受可溶性固形物含量(SSC)为32%、SO_2添加量为200mg/L、酒精含量为16%Vol、pH为2.0的环境;RY1酵母具有较强的发酵性能及耐受能力,适宜发酵杨梅果酒,DY5和JW14酵母具有较好的产香能力,适宜辅助发酵为杨梅酒增香。     

混菌顺序发酵对赤霞珠干红葡萄酒品质的影响

为研究不同非酿酒酵母与酿酒酵母混合发酵对葡萄酒品质的影响,选用2种商业非酿酒酵母（编号为CT10、PL09）分别与3种商业酿酒酵母（编号为MST、CEC01、F33）以1∶1混合顺序发酵,得到赤霞珠葡萄干红葡萄酒样（编号为CM、CC、CF、PM、PC、PF）,并分析各酒样的理化指标、颜色参数、酚类物质含量及感官品质。结果表明,与酿酒酵母单菌发酵相比,混菌发酵将发酵期延缓了2～3 d,总酸、干浸出物含量分别增加3.20%～7.75%和0.20%～3.47%,且提升总色素、聚合色素的稳定性,并提高酚类物质含量。其中酒样CM、PF中单宁、总酚、总黄酮含量分别提升2.30%、17.74%、44.68%,50.96%、19.02%、15.34%;酒样CM总花色苷含量提升22.90%,而酒样PF降低31.25%;酒样CM、PF香气复杂,口感圆润饱满,感官评分均为“优秀”,分别比对照提高35.81%、22.23%。综上,添加非酿酒酵母混菌发酵有助于提升赤霞珠干红葡萄酒的品质。     

浓香型白酒固态发酵规律模型的预测研究

针对固态发酵过程的控制实现困难的问题,本文通过测定窖池发酵过程中各个阶段的酒醅酒精数据,并对其进行优化,建立了BP人工神经网络来对窖池酒精发酵规律进行预测。通过训练,得到了良好的酒精发酵过程时间模型,并对窖池的空间位置的酒精含量变化进行建模,得到了边长-周长-产量的三维图形。最后测定了主要发酵阶段与酒精产量密切相关的酵母的数量,通过所得的酵母数据与酒精数据进行相关性分析,论证了预测模型的可靠性。