杂醇油与白酒生产质量

<正>杂醇油是白酒中最重要的三大芳香组分之一,是三个碳以上的一元醇类物质的总称,其主要成分是正丙醇、正丁醇、异丁醇、异戊醇等高级醇。但是,白酒中如果杂醇油含量过高,对人体有毒害作用,他对人体的中毒和麻醉作用比乙醇强,能使神经系统充血,使人感觉头疼。它还是白酒苦味和涩味的主要来源之一,同时也是造成白酒出现白色浑浊的原因之一。在白酒酿造过程中,杂醇油可由降解代谢路径和合成代谢路径两种途径形成。降解代谢途径中,杂醇油由氨基酸形成,发酵过程中的氨     

浅谈杂醇油

酒精发酵,除生成乙醇外,还有甲醇和丙醇以上的高级醇类,是由蛋白质经过分解代谢途径,由氨基酸生成的产物.通常包括异戊醇、异丁醇、正丙醇(浓香型白酒还包含有较多量的正丁醇,少量的己醇等)、异丙醇、叔丁醇、正戊醇、仲戊醇(即2-戊醇)、叔戊醇、正己醇、异己醇、庚醇、正辛醇、仲辛醇(2-辛醇)、异辛醇、丁二醇、2,3-丁二醇、丙三醇(甘油)、甘露醇(即己六醇)、赤藓醇、阿拉伯醇、环己六醇、十一醇、十二醇(月桂醇)、肉桂醇、糠醇、壬醇、癸醇、β-苯乙醇等.通常所说的高级醇是异丁醇和异戊醇,在水溶液中呈油状物,所以又叫杂醇油.     

高粱固态白酒发酵中菌类产生高级醇的研究

以正丙醇、正丁醇、异丁醇、异戊醇、正戊醇为高级醇代表，研究它们在酒精度８°的液体高粱培养基中的蒸出率，得出这５种醇各自的蒸出曲线。在此基础上，研究从白酒固态发酵曲粉和酒醅中分离，并经初步鉴定的优势菌株产生高级醇的能力。结果是酵母菌３３株（分属于８个属）均可产生异丁醇和异戊醇，而正丙醇、正丁醇、正戊醇则由不同的酵母菌株产生，芽孢菌１１个种均产生正戊醇，只有个别菌种产生异戊醇。霉菌１５株（分属于１１个属）中大部分菌株不产高级醇，只有个别菌株产生少量的异丁醇和异戊醇。     

发酵温度对浓香型白酒杂醇油含量的影响

为探究发酵温度对浓香型白酒生产中杂醇油生成量的影响，该研究利用可实现夹套控温的固态发酵罐为发酵容器，分别进行两轮“控温发酵”实验，对控温发酵罐、未控温发酵罐（对照）和窖池发酵过程中糟醅中及基酒中的杂醇油进行对比分析。结果表明，通过控制固态发酵罐夹层水温可有效实现对发酵糟醅温度的控制，且第一轮控温后与对照罐（32.4 ℃）相比，控温后顶温（35 ℃）更高，中挺时间更长（13 d）；第二轮控温后发酵罐糟醅形成了2 ℃以上的温差，温度较高的发酵罐中挺时间较长（15 d）；经气相色谱分析检测发酵温度较高的发酵罐，其糟醅中正丙醇、异丁醇、正丁醇、异戊醇、正己醇等杂醇油含量增加了118.6%、21.2%、29.7%、21.7%、77.3%，其二段基酒中正丙醇、正丁醇、异戊醇、正己醇等杂醇油含量也较发酵温度较低的发酵罐高22.3%、0.6%、2.0%、25.4%。     

酒精生产中杂醇油的生成与提取

酒精生产中杂醇油的生成与提取徐庭超（大连轻工业学院）杂醇油是指碳原子超过２的脂肪醇混合物，是酒精发酵的副产物，其主要成份为异戊醇、丁醇、正丙醇，另外还有少量正戊醇和正丁醇。一杂醇油对酒质的影响杂醇油在酒精中是以杂质出现的。根据国家规定，优级食用酒精标...     

蒸煮处理对红枣白兰地中高级醇含量的影响

采用GC-FID法对红枣白兰地中高级醇含量进行了分析测定。结果表明:蒸煮处理对正丙醇含量影响不显著,能够显著增加异戊醇的含量,而异丁醇的含量显著降低;不同层对正丙醇、异丁醇、异戊醇含量影响均不显著;不同取样时间对正丙醇含量影响不显著,而对异丁醇和异戊醇有显著的影响,其中,酒头中异丁醇和异戊醇含量与中间酒和酒尾中相比显著增加,而中间酒与酒尾中异丁醇和异戊醇含量没有显著差异。为提高红枣白兰地的经济价值和大规模生产提供理论依据。     

啤酒风味物质研究（二）——高级醇类的生成与抑制

啤酒中的高级醇习惯称为杂醇油，是不可避免的副产物，杂醇油以异戊醇为主，其次是活性戊醇，正丙醇和异丁醇，此外尚有色醇，酪醇，苯乙醇和糠醇等，下面分别阐述高级醇类的生成与抑制机制。     

荔枝酒中杂醇油含量的测定

采用气相色谱法,以叔戊醇为内标物,对荔枝酒中杂醇油的含量进行了测定,并与分光光度法进行了比较分析。实验结果表明,气相色谱法不仅可以检测出荔枝酒杂醇油总量,还能检测出杂醇油组分的含量;荔枝酒中,杂醇油含量较多的成分分别为异戊醇、异丁醇和正丙醇,荔枝干酒中三者含量之和占到杂醇油总量的99.0%;分光光度法是以异丁醇和异戊醇的含量作为杂醇油总量,该法无法检测到荔枝酒中正丙醇的含量,不能准确测定荔枝酒中杂醇油含量,气相色谱法具有简单、快速、精密度高等特点,较分光光度法更适合于荔枝酒中杂醇油含量的测定。     

不同发酵层和取样时间对红枣白兰地甲醇和高级醇含量的影响

以山区特产大枣为原料,采用固态发酵方法生产红枣白兰地,研究了不同发酵层和不同取样时间对红枣白兰地中甲醇和高级醇含量的影响。结果表明,不同取样时间对甲醇、异丁醇和异戊醇含量的影响显著,但对正丙醇含量影响不显著。其中,酒尾中甲醇含量与酒头、酒基中甲醇含量相比显著增加,而酒基与酒头中甲醇的含量差异不显著;酒头中异丁醇和异戊醇含量与酒基和酒尾中相比显著增加,而酒基与酒尾中异丁醇和异戊醇含量没有显著差异。不同发酵层对甲醇、正丙醇、异丁醇、异戊醇含量的影响均不显著。     

啤酒中高级醇的控制

高级醇是酵母发酵主要副产物 ,主要有正丙醇、正丁醇、异丁醇、正戊醇、异戊醇等 ,可由发酵过程中的降解代谢和合成代谢生成。控制高级醇含量的措施有 :①选用产高级醇含量低的酵母菌株 ;②选用蛋白质溶解良好的麦芽 ;③调整工艺 ,控制麦汁含量6.0×10-6～8.0×10-6,降低主发酵温度 ;④控制糖化麦汁pH在5.2～5.4之间。(孙悟)     

MUTANT STRAINS OF SACCHAROMYCES YEDO PRODUCING EXCESSES OF FUSEL ALCOHOLS

The possibility of increasing the production of fusel alcohols in fermentation with Saccharomyces yedo by means of induced mutations has been investigated. Mutations were induced by UV-irradiation and mutants that could be expected to produce excesses of isobutyl alcohol, isoamyl alcohol and optically active amyl alcohol were selected in a medium containing norvaline—a partial leucine antagonist. Thus, in the selection of mutants, the relationship between the biosynthesis of amino acids and the formation of higher alcohols was exploited. Using this technique, two different mutants were isolated. In the fermentation of a synthetic medium which was initially lacking in amino acids, one of the mutants produced excess of isoamyl alcohol while the other mutant produced excesses of both isobutyl and isoamyl alcohol.     

Enhanced production of isoamyl acetate from beet molasses with addition of fusel oil by Williopsis saturnus var. saturnus

Fusel oil which contains high level of amyl alcohols (approximately 45–55%) is a by-product obtained from the distillation of alcohol made by fermentation of molasses. Williopsis saturnus is a yeast which is able to convert isoamyl alcohol into isoamyl acetate. The aim of this study was to increase the formation of isoamyl acetate by the addition of fusel oil at the ratios of 1%, 2% and 3% (v/v) to molasses based fermentation medium using W. saturnus. It was found out that bioconversion of added fusel oil into isoamyl acetate was possible and an addition of 1% fusel oil led to an increase in isoamyl acetate concentration from 118 to 354 mg/L.     

REDUCTION OF HIGHER ALCOHOLS BY FERMENTATION WITH A LEUCINE-AUXOTROPHIC MUTANT OF WINE YEAST

Several auxotrophic mutants requiring branched chain amino acids (valine, leucine, or isoleucine) were isolated in a strain of Montrachet wine yeast. They were tested for their ability to produce lowered amounts of higher alcohols (‘fusel oil’: isobutyl, active amyl, and isoamyl alcohols) in grape juice fermentations. One strain which required leucine was especially good in this respect. This mutation is recessive and is the result of a deficiency for the enzyme α-isopropylamate dehydratase. In trial fermentations with this mutant, the resulting wines contained up to 20% less total fusel oil and 50% less isoamyl alcohol compared to the parent Montrachet strain. An experienced taste panel did not discern any gross degradation of taste quality in wine made with the mutant strain compared to that made with the parent strain. The mutant strain could be of commercial importance in preparation of distilling material for alcoholic beverages since the reduced fusel oil content would not require any special distillation procedures which are normally used to avoid the unpleasant flavour associated with concentrated higher alcohols. Reduction of the isoamyl alcohol content is particularly significant since this fusel oil component is usually present in the highest amount.     

利用杂醇油提取正丙醇的研究

利用二氧化锰和活性炭将发酵法生产酒精和白酒的副产物杂醇油中的有色化合物吸附除去，然后采用逐级蒸馏法从中提取工业正丙醇。结果表明，正丙醇的回收率为82．85％，纯度为93．2％。该方法适用于从杂醇油中回收正丙醇。为工厂废物利用提供一种有效途径。     

INFLUENCE OF THE CONCENTRATION OF BRANCHED CHAIN AMINO ACIDS ON THE FORMATION OF FUSEL ALCOHOLS

The influence of concentrations of branched-chain amino acids on the total, anabolic and catabolic production of isobutyl, active amyl, and isoamyl alcohol by Saccharomyces cerevisiae X 2180-1A has been examined in media with high nitrogen levels. It has been found that the total and catabolic production of higher alcohols increased with increasing concentrations of the corresponding amino acids. The anabolic pathway can be suppressed by high levels of the corresponding amino acid. Lower concentrations up to 1 mm for isoleucine and 10mm for leucine stimulate the anabolic formation of active amyl alcohol and isoamyl alcohol respectively. From the data obtained, it is shown that, under the conditions used, 50% or more of the fusel alcohols may arise in a beer wort fermentation from carbohydrates.     

有机酸含量对葡萄酒发酵的影响

为了考察有机酸含量对葡萄酒发酵的影响,在初始有机酸含量分别为4 g/L、7 g/L和10 g/L的模拟葡萄汁中接种酵母,于25 ℃发酵,比较不同初始有机酸含量对葡萄酒发酵过程中酵母生长、降糖、有机酸及挥发性化合物含量的影响。结果表明,初始有机酸含量7 g/L时酵母生长和耗糖最慢,乙醇和乙醛产生量最低;随初始有机酸含量升高,pH值、酒石酸、苹果酸、乳酸、乙酸、总酸、乙酸乙酯和总酯含量呈下降趋势;琥珀酸、正丙醇、异丁醇、异戊醇及总高级醇含量呈上升趋势;但对β-苯乙醇、正丁醇及丁酸乙酯含量影响较小。初始有机酸含量10 g/L的葡萄酒发酵过程酵母生长快、降糖最快,产酸含量适中,同时香气较好。因此,葡萄酒发酵的适宜初始有机酸含量为10 g/L。     

蛋白酶对酱香型白酒中杂油醇含量的影响研究

酱香型白酒发酵过程中,研究的蛋白酶添加量对杂油醇生成的影响,结果表明:蛋白酶添加量对杂油醇的生成有一定的影响,在0～20 U/g范围内,杂油醇生成量随蛋白酶添加量的增加而降低,蛋白酶为20 U/g时,杂油醇生成量最低为0.231 g/L,相对于未添加蛋白酶降低60.52%,添加量超过20 U/g时,杂油醇生成量随蛋白酶添加量的增加而增加,各杂油醇单体(异丁醇、正丙醇、异戊醇)变化趋势和总杂油醇变化趋势相似。     

不同品种甘蔗汁酿造的银朗姆酒中杂醇油含量测定

为探索酿酒原料对银朗姆酒中杂醇油含量的影响,采用冷汁生石灰澄清法对甘蔗汁进行处理,经18 ℃低 温发酵和蒸馏后,选取中间蒸馏组分,调配成40%（V/V）的基础酒,利用气相色谱法进行分析。结果显示：银 朗姆酒中异戊醇含量最高,占杂醇油总量的46.70%～63.22%;其次为正丙醇和异丁醇,分别占20.26%～36.08%和 14.47%～15.87%;正丁醇和正戊醇含量较低。6 种蔗汁原料酒中,大黑熊品种的银朗姆酒中杂醇油含量最高,达到 389.54 mg/L,其次是蔗94128（316.91 mg/L）、台优（312.27 mg/L）、粤00236（295.83 mg/L）,含量较低的为台 22（254.76 mg/L）和桂00122（239.48 mg/L）。本方法可快速、准确检测银朗姆酒中杂醇油的含量,用以选择适宜 酿酒的甘蔗品种。