浅谈麦汁糖类组成对啤酒发酵度的影响

本文从酵母吸收糖类顺序的生理特性，阐述增加麦汁中葡萄糖等单糖含量对提高发酵度的重要性；并从10°P干啤酒中麦汁糖类组成的分析情况进一步说明其副发酵度的影响。我们通过添加淀粉酶及调整糖化工艺，提高了麦汁中可发酵性糖含量，改变了麦汁中葡萄糖、麦芽糖、麦芽三糖的比例，使三者比例约为65：23：12，而普通啤酒一般为10～15：67～72：18～22，显然增加了葡萄糖含量。并从发酵中证实麦汁糖类组成对提高发酵度是关键要素，使用普通酵母也能生产高发酵度的干啤酒。     

制备高辅料比啤酒麦汁的工艺研究——应用砻糠强化麦汁过滤

本文叙述了啤酒酿造中采用酶制剂技术以后，大米辅料从４５％提高至５５％。添加２％大米用量的砻糖有助于缩短麦汁过滤时间而对成品啤酒主要指标无副作用且不影响啤酒口味。     

糖化酶对高粱Lager啤酒麦汁组成和糖酵解的影响

我们进行了一个置信度P〈0．05的三因子实验，利用大麦麦芽（BM）或高梁芽（SM），精选玉米（MZ）或腊质高梁（WXSOR）粉粒为辅料，添加或不添加糖化酶（AMG）生产Lager啤酒，研究其144h发酵过程中糖酵解和乙醇生成情况。在BM麦汁中，葡萄糖、麦芽糖、麦芽三糖分别占总可发酵糖的20％，68％和13％，而这个比例在SM麦汁中则分别为35％，48％和17％。添加AMG后，麦汁中葡萄糖含量从9．3g／L增加到24．5g／L，总可发酵性糖含量用g葡萄糖／L表示，从59．2g／L增加到72．6g／L。和BM麦汁相比，SM麦汁的葡萄糖含量约高50％，而初始麦芽糖则要低40％左右。用WXSOR或MZ作酿造辅料，生产的麦汁和啤酒具有相似的特性。AMG的添加使麦汁中葡萄糖量增加2．5倍以上，并使可发酵性糖量增加23％以上。线性回归分析表明发酵过程中可发酵性糖的消耗符合一级反应方程。葡萄糖、麦芽糖和麦芽三糖消耗50％的时间分别为49h，128h和125h，这清楚地表明酵母优先利用葡萄糖。和不添加AMG的麦汁相比，添加AMG麦汁中的麦芽糖和麦芽三糖的消耗速度分别加快和变慢了。发酵终了，BM啤酒的乙醇含量（5．1％，v／v）比SM啤酒（3．9％，v／v）要高。在添加AMG的啤酒生产中，用BM还是用SM及添加MZ辅料在最终的乙醇浓度上并无明显区别。研究结果表明，AMG可以降低糊精含量，增加初始葡萄糖量和总可发酵性糖量，特别是在利用SM为原料的时候，该现象更为明显。     

麦汁组成对快速发酵中酵母代谢的重要性

在啤酒发酵过程中可以通过提高酵母接种量或者高浓酿造来提高产量,然而,这两种技术对酵母的新陈代谢都有显著的影响。在这项研究中,对高浓度酿造和高酵母数发酵相结合对酵母的生理和风味物质生成的影响进行了评价。此外．试验在快速发酵系统中通过优化麦汁中游离氨基氯含量来降低总双乙酰的产生,较高的麦汁浓度会导致酵母活力的下降,这与海藻糖含量的增加及与压力相关的基因表达水平的增加有关。不只是麦汁浓度。不同的可发酵性糖含量对酵母发酵性能及风味物质的生成都有强烈的影响。麦汁中高含量的蔗糖对氨基酸的吸收、酵母的生长、糖原的形成、海藻糖的重复利用、乙酯的合成和总双乙酰的还原速度都有促进作用．与其他的高浓度麦汁相比．酵母处于高浓度蔗糖环境中会经历更高的渗透压和压力相关的影响。尽管蔗糖相比于麦芽糖可以促进转录激活因子ATFI的活性,可以观察到乙酸酯类明显的降低。但是考虑到蔗糖对酵母性能的不利影响,采用蔗糖和麦芽糖组合来提高麦汁浓度还是可取的。     

HPLC测定啤酒和麦汁中的糖类化合物

ＨＰＬＣ测定啤酒和麦汁中的糖类化合物魏玲（北京双合盛五星啤酒集团公司啤酒研究检测中心）糖类的分析测定在啤酒生产过程中具有重要意义。糖类测定方法很多，一般的化学分析方法，如比色法、滴定法、旋光法、比重法等只能测定总糖和还原糖。近十多年来随高效液相色谱法...     

麦汁组成对快速发酵中酶母代谢的重要性

在啤酒发酵过程中可以通过提高酵母接种量或者高浓酿造来提高产量,然而,这两种技术对酵母的新陈代谢都有显著的影响.在这项研究中,对高浓度酿造和高酵母数发酵相结合对酵母的生理和风味物质生成的影响进行了评价.此外,试验在快速发酵系统中通过优化麦汁中游离氨基氮含量来降低总双乙酰的产生.较高的麦汁浓度会导致酵母活力的下降,这与海藻糖含量的增加及与压力相关的基因表达水平的增加有关.不只是麦汁浓度,不同的可发酵性糖含量对酵母发酵性能及风味物质的生成都有强烈的影响.麦汁中高含量的蔗糖对氨基酸的吸收、酵母的生长、糖原的形成、海藻糖的重复利用、乙酯的合成和总双乙酰的还原速度都有促进作用.与其他的高浓度麦汁相比,酵母处于高浓度蔗糖环境中会经历更高的渗透压和压力相关的影响.尽管蔗糖相比于麦芽糖可以促进转录激活因子ATF1的活性,可以观察到乙酸酯类明显的降低.但是考虑到蔗糖对酵母性能的不利影响,采用蔗糖和麦芽糖组合来提高麦汁浓度还是可取的.     

啤酒酿造过程中有机酸的研究

研究不同的糖化工艺对麦汁中有机酸含量的影响。通过改变原料状况（不同的辅料比、粉碎度）、糖化水pH、糖化温度、糖化时间等工艺参数,发现麦汁中的有机酸主要来自麦芽呼吸产生的酸,糖化过程中的酶解作用几乎不产生有机酸,且麦芽原始酸和总有机酸含量之间具有较好的线性关系（R^2=0．943）。麦汁煮沸时添加酒花和钙离子,可以使麦汁中的有机酸含量下降10％。     

糖化工艺对麦汁糖组分的影响

本文探讨在麦汁制备过程中，不同的糖化工艺对麦汁糖类成分的影响。在生产中，必须针对实际情况，制定合理的糖化配方，以得到适合的麦汁糖组分。     

麦汁煮沸过程中加热器表面结垢对麦汁质量的影响分析

麦汁加热和煮沸受加热器结垢程度的影响，加热器表面结垢可能会导致各批次的麦汁质量有差异。许多酿造厂已证明这种情况的发生。如果连续生产几锅麦汁而中间不对加热器进行洗涤。污垢层的存在导致热传递受阻，麦汁热负荷增加。实验分析了在不同结垢程度下生产麦汁的含氮物质组成，并指出了克服麦汁质量下降的方法。     

国内啤酒有机酸组成及其综合评价

有机酸是对啤酒质量(口感和稳定性)有重要影响的一类物质,本文通过采用HPLC法测定国内市售的20种啤酒中主要有机酸的含量,且采用统计学中多指标综合评价法,建立了以6种有机酸(丙酮酸、苹果酸、乳酸、乙酸、柠檬酸和琥珀酸)为指标综合评价啤酒的方法。通过该方法可以对啤酒或者试验样品进行整体性比较和“优劣”排序,对研究啤酒中有机酸类物质的组成有重要意义。     

Impact of Dark Specialty Malts on Extract Composition and Wort Fermentation

Dark specialty malts are important ingredients for the production of several beer styles. These malts not only impart colour, flavour and antioxidative activity to wort and beer, they also affect the course of wort fermentations and the production of flavour‐active yeast metabolites. The application of considerable levels of dark malt was found to lower the attenuation, mainly as a result of lower levels of fermentable sugars and amino acids in dark wort samples. In fact, from the darkest caramel malts and from roasted malts, practically no fermentable material can be hydrolysed by pilsner malt enzymes during mashing. Compared to wort brewed with 50% pilsner malt and 50% dark caramel malt or roasted malt, wort brewed with 100% pilsner malt contained nearly twice as much fermentable sugars and amino acids. Reduced levels of yeast nutrients also lowered the fermentation rate, ranging from 1.7°P/day for the reference pilsner wort of 9 EBC to 1.1°P/day for the darkest wort (890 EBC units), brewed with 50% roasted malt. This additionally indicates that lower attenuation values for dark wort are partially due to the inhibitory effects of Maillard compounds on yeast metabolism. The application of dark caramel or roasted malts further led to elevated levels of the vicinal diketones diacetyl and 2,3‐pentanedione. Only large levels of roasted malt gave rise to two significant diacetyl peaks during fermentation. The level of ethyl acetate in beer was inversely related to colour, whereas the level of isoamyl acetate appeared to be affected by the use of roasted malt. With large levels of this malt type, negligible isoamyl acetate was generated during fermentation.     

反相高效液相色谱法(RP-HPLC)测定啤酒中有机酸

建立了一种利用反相高效液相色谱法同时测定啤酒中 9种有机酸的方法。应用反相C18色谱柱Nucleosil 10 0C18　 2 5 0× 4 0mm ,以 0 1mol/LKH2 PO4(用H3 PO4调 pH3 0 )为流动相 ,紫外检测 2 15nm ,将啤酒中草酸、丙酮酸、苹果酸、α 酮戊二酸、乳酸、乙酸、柠檬酸、富马酸、琥珀酸一次性分离。除柠檬酸外各种有机酸的回收率在 85 %以上 ,变异系数 <5 %。该方法简便、快速、准确。此外 ,对影响有机酸分离的因素进行了研究 ,并测定了国内市售的十几种啤酒中的有机酸含量     

啤酒有机酸类物质研究进展

有机酸类物质是啤酒中一类重要的化合物，其组成和含量不仅影响啤酒的风味，而且与酵母的活力也有较密切的联系。文中参照国内外研究资料，从有机酸对啤酒风味的影响以及有机酸的代谢与酵母活力之间的联系阐述有机酸类物质对于提高啤酒质量的重要性。     

Influence of Lauter Turbidity on Wort Composition,Fermentation Performance and Beer Quality in Large‐Scale Trials

Different lauter turbidities (standard 43 EBC vs. turbid 82 EBC on average) were obtained by variation of the lauter procedure, particularly deep raking, in this study. The resulting worts were used for repitching the respective yeast into six subsequent fermentation cycles. The resulting beers were investigated in terms of flavour quality, flavour stability, non‐biological stability and foam stability. Worts gained from turbid lautering showed very similar analytical data compared to the controls (except for a slight but significant increase in linoleic acid). There was an improvement in fermentation performance in terms of a pH decrease and a decrease in extract. The resulting beers were quite similar, and the staling indicators increased slightly, but not significantly, due to turbid lautering. Both types of beer were evaluated on tasting as being of a high flavour quality and neither a professional panel nor a non‐professional (customer) panel was able to distinguish the difference, between standard and turbid lautering, in terms of fresh and forced aged beers. Due to turbid lautering the non‐biological stability appeared to be slightly, but not significantly, decreased while on the other hand the foam stability was significantly improved due to turbid lautering. In conclusion, fermentation performance may be improved by more turbid lautering, and the negative consequences often reported for the resulting beers appear to be overestimated, since the quality parameters of the final beers had not deteriorated significantly.     

啤酒麦芽汁的制备研究

以麦芽为主料、大米为辅料制备麦芽汁。采用正交试验设计研究外加酶糖化法中酶的添加量、投料温度、蛋白质休止时间及第一阶段糖化（糖化Ⅰ）时间对麦芽汁品质的影响,并与标准协定法糖化制备麦芽汁相比较,以麦芽汁中α-氨基氮和糖度含量来比较两种工艺的优劣,确定较佳的糖化工艺路线。得出具有优良品质麦芽汁的较优糖化工艺参数对麦芽汁中α-氨基氮和糖度含量的影响规律。结果表明,投料温度对α-氨基氮影响较为明显,而蛋白质休止时间对糖度影响较为显著。最佳工艺条件为：糖化酶的添加量30U／g,投料温度35℃,蛋白质休止时间60min,糖化Ⅰ时间30min。     

Influence of Lauter Turbidity on Wort Composition,Fermentation Performance and Beer Quality — A Review

This review paper covers a variety of aspects concerning lauter turbidity and wort clarity that have been published in the past decades. The components of wort which are connected to an increased lauter turbidity, such as lipids and long‐chain fatty acids, are presented as well as how the further steps of wort production, i.e. wort boiling and clarification, have an impact thereon. Besides the influence of lauter turbidity on wort quality, technical aspects affecting lauter turbidity are discussed by comparing different lauter systems such as lauter tun, mash filter and strainmaster. It is further highlighted, how lauter turbidity and its components influence fermentation performance and yeast vitality. Finally, the consequences of increased wort turbidity for the resulting beers in terms of flavour quality, flavour stability, non‐biological stability and foam stability are described.     

The Effect of Hydroxycinnamic Acids and Volatile Phenols on Beer Quality

To the consumer, beer should be an agreeable beverage of attractive colour, clarity, pleasing flavour and should carry no toxic substances. One of the major constituents of barley is phenolic acids and their direct effect on the quality of beer is still a mystery. The aim of the study therefore was to investigate the relationship between phenolic acids during mashing at different temperatures and the quality of the beer. The mash regime and liquor to malt ratios were optimised and the carbohydrates obtained were analysed at 3.5 L of water per kg of malt and a total mash time of 105 min. Carbohydrate and phenolic acid analyses were performed by HPLC coupled with a UV‐vis detector. The three different malts used had a phenolic acid content of 33.25 μg/mL, 25.44 μg/mL and 19.98 μg/mL for malt A, B and C, respectively. The plot of 1/T versus Ln(t) gave a negative slope with activation energy (E_a) = 209 KJ/mol, rate constant (k) = 4.6 × 10^?4 mg/L min, which are comparable to similar data reported in the literature. The kinetics studies showed that the optimised mashing temperature of 90°C was adequate to form 4‐vinylguaiacol by thermal decarboxylation from the hydroxycinnamic acids. This study has shown that there is no direct correlation between phenolic acids and oxidative flavour stability of beer while the corresponding volatile phenols may affect beer flavour.     

啤酒、麦汁中花色苷的快速测定方法

采用分光光度计于420nm测定样品吸光度,根据换算系数计算出其花色苷的含量,以指导生产。该法快速准确,较之其他分析方法,具有简便、误差小、重现性好的特点。