野生蓝莓冰酒发酵工艺及其香气成分的研究

目的以人工冰冻野生蓝莓为原料,在不外加糖源条件下,探究酿造野生蓝莓冰酒皀冰冻压榨、低温发酵工艺。方法通过单因素和正交试验优化发酵工艺,采用冰冻压榨和优化后皀低温发酵工艺制作蓝莓冰酒,采用传统工艺制作蓝莓酒,对2种酒按照国家标准进行感官、理化指标检测,采用气相色谱-质谱联用法(gas chromatography-mass spectrometry,GC-MS)进行香气成分分析。结果适宜酿造蓝莓冰酒酵母为GX1201,最佳发酵温度为12℃,酵母添加量为1.4%,残糖量为165 g/L;蓝莓冰酒皀感官评分优于蓝莓酒,同时经GC-MS法香气分析,蓝莓酒和蓝莓冰酒主香型一致,蓝莓冰酒含有15种香气物质明显高于蓝莓酒,拥有更加丰富皀香气层次。结论使用长白山野生蓝莓,经冷冻浓缩、冷压榨后,在不外加糖源皀情况下,酿造皀野生蓝莓冰酒,各项理化指标和感官指标,均符合标准,酿造出皀蓝莓冰酒口感醇厚,果香酒香浓郁、纯正、圆润、独特。     

苹果酸-乳酸发酵对威代尔冰酒香气的影响

以酒精发酵与苹果酸-乳酸发酵同时进行的威代尔冰酒为实验组,以单一酒精发酵的冰酒为对照,采用液相色谱（LC）、顶空固相微萃取（HS-SPME）和气相色谱-质谱联用（GC-MS）技术,对有机酸含量和挥发性香气成分进行定性定量检测,同时进行感官评定,探究苹果酸-乳酸发酵对威代尔冰酒香气的影响。结果表明,苹果酸-乳酸发酵能使冰酒中苹果酸含量降低26%,乳酸含量增加50%,显著提高冰酒中脂肪酸乙酯类（34.71%）和萜类香气物质含量（15.2%）（P＜0.05）,显著降低戊醇等高级醇类含量（12.19%）（P＜0.05）,提高冰酒的花香、果香、焦糖香,显著降低化学味。感官分析结果表明,苹果酸-乳酸发酵能增加冰酒中的果香、花香,降低冰酒酸度,提高糖酸平衡感,从而提高其整体接受度。     

桓仁产区优良冰酒酵母菌株的筛选及酿造特性评价（英文）

为获得可用于东北桓仁地区威代尔冰酒生产的酿酒酵母菌株,采用一种快速的酵母菌株筛选方法,通过测定菌株乙醇和二氧化硫耐受性,从威代尔冰酒自然发酵过程中筛选到9株酿酒酵母菌株。进一步酿造实验结果显示,所筛选的酿酒酵母可以顺利完成冰酒发酵,产生的香气轮廓与商业酵母DV10相比也不同(主成分分析结果),最终获得了2株具有高发酵活力且香气特征与商业酵母差异显著的酵母菌株SC42和SC45,其中SC42能够高产高级醇和酯类物质,并且低产乙酸,而SC45能够产生高含量的甘油、酯类物质以及反式玫瑰醚和β-大马士酮。结果表明,采用本研究的筛选方法能够快速有效地筛选到具有应用潜力的冰酒生产菌株,同时也证明了使用本土野生酵母菌株能够有效地改善冰酒香气品质,生产出与接种商业酵母不同风格的冰酒产品。     

冰酒生产工艺及其品质影响因素

阐述了冰酒的生产工艺过程。葡萄在葡萄园中经自然冰冻后采摘，并在冰冻状态下压榨。采摘和压榨均须在-8℃以下进行，使汁中浓缩很高的糖、酸和风味成分。葡萄汁在10℃-12℃缓慢发酵数周，然后在桶中陈酿数月。结果表明，雷司令是一种理想的冰酒酿造原料，此外，冰葡萄采摘温度和葡萄汁发酵温度也是影响冰酒品质的主要因素。     

苹果酒发酵过程中酵母营养的研究

苹果汁发酵常出现发酵迟滞或停滞的现象，影响苹果汁发酵迟滞或停滞的主要原因是酵母的营养问题，即可同化氮源和维生素。为此，本文通过单因素试验研究了磷酸氢二铵（DAP）、硫酸铵、硫胺素、肌醇、烟酰胺、吡哆醇、生物素、泛酸等八种营养素对发酵的影响。结果表明，磷酸氢二铵（DAP）、硫酸铵、硫胺素及生物素的添加都对酵母代谢有显著影响，当添加量分别为400、1200、0．30及0．20mg／L时，酒精度达到最大值，酵母代谢最为旺盛。     

全球冰酒法规现状

冰酒的制造需要天然的地理环境、气候条件和土壤条件,需要优秀的寒地产区、自主选育的抗寒葡萄品种、严格的原料种植采摘管理、自主培育的酵母、独特的超低温发酵工艺等。冰酒的产量非常低,而且很多地区都不是年年都能生产,所以其价格相对比较昂贵,而且市场上的产品质量参差不齐,真假难辨。针对于此,世界上的冰酒主要生产国都制定了相应的冰酒标准,对于葡萄的采摘和压榨温度、糖度、残糖、酒精含量等做了详细的规定,其中德国、加拿大、奥地利以及OIV等的标准中都特别强调葡萄必须要自然冰冻于枝头之上,不能采用任何人工冷冻法或用所谓的冷冻萃取法（cryoextraction）来酿造冰酒等。美国和瑞士对此没有做规定,但瑞士对这样的“冰酒”在标签上要标注“冷冻”字样（cryo）,美国新的葡萄酒标签法律也限定“icewine”只能用于自然冰冻葡萄酿造的冰酒。下面让我们来了解一下世界上的一些主要的冰酒法规。     

冰葡萄酒威代尔的酿造工艺

冰酒是采用天然冰冻的完全成熟并且晚收的葡萄经低温发酵酿制而成的一种风味独特的甜型葡萄酒.本文主要研究了辽宁桓仁产区采用威代尔葡萄酿造冰酒的工艺,包括采摘、榨汁、低温发酵、澄清、橡木桶陈酿等过程.     

蓝莓类冰酒发酵工艺研究

冰酒受自然因素影响很大,因此价格高昂。文中对人工制冷冰冻的工艺进行优化,通过3种不同的酵母菌在蓝莓类冰酒发酵过程中理化指标的变化规律,并对蓝莓类冰酒进行感官评定,筛选出酿造蓝莓类冰酒的优良菌株。最终确定酿酒酵母1970为蓝莓类冰酒酿造的优良菌株。利用筛选出来的酵母菌发酵酿制蓝莓类冰酒,研究了酵母添加量、温度、初始酸度、初始糖度等因素对发酵的影响。通过正交实验确定了蓝莓类冰酒的最佳发酵条件为酵母添加量5%、温度25℃、初始p H3.4、初始糖度18°Bx。产品果香浓郁、酒质净爽,具有典型的冰酒品质。     

不同有孢汉逊酵母与酿酒酵母混合发酵对威代尔冰葡萄酒香气的影响

为了研究菌株和接种方式对冰葡萄酒非挥发性产物和挥发性香气成分的影响,选用2株自筛非酿酒酵母——仙人掌有孢汉逊酵母(Hanseniaspora opuntiae)和葡萄汁有孢汉逊酵母(Hanseniaspora uvarum),分别与商业酿酒酵母DV10混合发酵。结果表明:H.uvarum与DV10同时接种混合发酵可以显著降低乙酸产量(降低26.90%);H.opuntiae与DV10同时接种混合发酵促进了酯类和萜烯类物质的合成,总量分别增产88.61%和21.40%,其中乙酸苯乙酯含量提高14.60倍,β-大马士酮增产8.85%。除此之外,感官品评结果显示H.opuntiae与DV10混合发酵可显著增强花果香和黄油味。综合分析,认为H.opuntiae更适合应用于冰葡萄酒发酵,为冰酒混合发酵的进一步研究提供了数据基础和理论依据。     

冰葡萄酒中高含量挥发酸的影响因素分析

在冰葡萄酒生产过程中常有挥发酸超标的现象,研究冰酒高含量挥发酸的影响因素对冰酒生产工艺的改进和完善意义重大。试验对可能影响冰酒挥发酸含量的因素:冰葡萄汁的初始糖含量、酵母种类及用量、发酵温度和是否添加酵母营养盐分别进行控制试验,比较测定小试发酵的冰酒的糖、酸、乙醇体积分数、甘油等主要质量指标。结果表明:冰葡萄汁初始糖度、发酵温度与挥发酸生成量呈显著正相关;发酵过程中所采用的酵母种类也会影响挥发酸的生成量,该研究中Y-3#酵母生成的挥发酸量最低;酵母用量以及添加酵母营养剂对冰酒挥发酸的生成量没有明显影响。同时,在分析的基础上,提出了降低冰葡萄酒挥发酸的工艺措施。     

Stuck and slow fermentations in enology: statistical study of causes and effectiveness of combined additions of oxygen and diammonium phosphate

One hundred and seventy-eight musts from different regions in France were selected by enologists and fermented under standardized conditions. Two kinds of fermentation problems were distinguished: (a) slow and (b) sluggish (late-onset sluggish) and stuck (with residual sugar) fermentations. Slow fermentations, characterized by a low fermentation rate throughout the process, were always due to low assimilable nitrogen concentrations in the must. The advantages of using formol titration for measuring assimilable nitrogen are discussed. In contrast, sluggish and stuck fermentations, characterized by very low yeast viability at the end of fermentation, could not be predicted from the analytical data even though their probability was increased when the initial sugar concentration was high. All problems of stuck and sluggish fermentations (concerning 40% of the musts) were solved by supplying 7 mg/l oxygen and 300 mg/l diammonium phosphate at the halfway of the fermentation process, which confirmed (i) the importance of these two nutrients in enological practices and (ii) the importance of adding them at the right time.     

Effects of temperature, ammonium and glucose concentrations on yeast growth in a model wine system

In enology, alcoholic fermentation is a complex process involving several mechanisms. Slow and incomplete alcoholic fermentation is a chronic problem for the wine industry and factors leading to sluggish and stuck fermentations have been extensively studied and reviewed. The most studied cause of sluggish and stuck fermentation is the nitrogen content limitation. Nevertheless, other factors, such as temperature of fermentation and sugar concentration can affect the growth of yeasts. In this study we modelled the yeast growth‐cycle in wine model system as a function of temperature, sugar and ammonium concentrations; the individual effects and the interaction of these factors were analysed by means of a quadratic response surface methodology. Cell concentrations and weight loss were monitored in the whole wine fermentation process. The results of central composite design show that lower is the availability of nitrogen, higher is the cell growth rate; moreover, initial nitrogen concentration also influences survival time of Saccharomyces cerevisiae.     

高浓酿造啤酒发酵周期的研究进展

高浓酿造是采用高浓麦汁发酵,之后进行稀释的啤酒酿造技术,该方法可显著提高生产效率,被广泛应用于啤酒生产中。虽然高浓酿造技术基本发展成熟,但仍存在发酵周期长以及后稀释造成风味不平衡的问题。由于高浓麦汁的特性,会导致发酵不彻底、发酵缓慢以至于延长发酵周期。该文分别从原料、发酵条件、菌株质量方面对高浓酿造啤酒发酵周期影响因素作了综合阐述,并对解决发酵周期长这一问题进行了讨论,提供可行思路。     

猕猴桃果醋生产工艺研究

研究了用叠式动态表面发酵塔酿制猕猴桃果醋的工艺条件,分析了发酵过程中各主要成分的变化,确定了最佳工艺参数。     

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.     

葡萄醋新型液态生产工艺研究

研究了用叠式动态表面发酵塔酿制葡萄醋的工艺条件,分析了发酵过程中各主要成分的变化,确定了最佳工艺参数。     

工业发酵中泡沫控制方法探讨

分析了工业发酵过程中泡沫产生的原因,介绍了化学消泡和机械消泡的作用机理,对常用的化学消泡剂以及不同结构机械消泡装置的消泡效果进行了评价.并在发酵液成分和操作工艺条件方面提出了泡沫控制措施,为工业生产中泡沫的消除提供了参考.     

中药渣固态发酵生产功能饲料的研究现状

目前在养殖业上,中药渣固态发酵主要用于生产饲料原料,事实上,中药渣固态发酵产生大量的益生菌、酶、活性肽、寡糖、有机酸等生物活性成分,更突出其功能性。该文重点对有关中药渣生产功能饲料的固态发酵菌种、发酵工艺以及产品功效进行综述,同时对产业化发展缓慢的原因加以探讨,旨在为中药渣固态发酵生产功能饲料的深入研究和产业化发展提供参考。     

利用苹果皮核开发苹果醋饮料技术研究

以苹果皮、核为主要原料,采用液体深层发酵技术,经酒精发酵、醋酸发酵生产苹果醋饮料。分析比较了苹果皮、核、汁与正常苹果汁的基本成分的差异;探讨了酵母菌种、醋酸菌种的驯化培养;通过正交试验对苹果醋饮料的配方和感官指标进行了优化。所生产的苹果醋饮料产品的质量达到了有关标准的要求。     

生米发酵食品的研究进展

生米发酵食品是一种重要的米制品种类,在我国具有悠久的发展历史。本文阐述了几种生米发酵食品的特点及大米在发酵过程中的微生物的变化情况及发酵对化学组成和理化性质的影响。发酵过程中微生物对大米中的物质进行降解,形成发酵制品的特殊风味,其中优势菌种为乳酸菌。发酵后淀粉的含量有所增加,脂肪、蛋白质和灰分的含量逐渐减少,但游离脂肪酸的含量增加。发酵有利于淀粉的糊化,较大地改变了大米制品的质地。随着对发酵米制品的制作机理的深入研究,生米发酵制品在食品工业中的应用将越来越广泛。