市售啤酒中嘌呤含量评价指标的研究

目的 建立市售啤酒中嘌呤含量的评价指标。方法 采用反相离子对色谱法对16种市售啤酒中嘌呤含量进行检测。结果 游离嘌呤碱基含量为5.72~26.52 mg/L,嘌呤核苷含量为40.14~135.56 mg/L,总嘌呤碱基含量为31.69~92.66 mg/L。游离嘌呤碱基和嘌呤核苷两部分之和与总嘌呤碱基含量间存在非常显著相关关系,相关系数为0.985(P＜0.01)。结论 以游离嘌呤碱基和嘌呤核苷为指标,可以满足不同啤酒间嘌呤含量的评价,检测方便快捷且能更好地反映啤酒中主体嘌呤物质。     

糖化工艺对麦汁色度的影响

啤酒色度是啤酒质量的一项重要指标。近年来色度淡而爽口的啤酒越来越受消费者欢迎,南方的消费者更有这种需求。     

糖化工艺对啤酒麦汁色度的影响研究

麦汁为啤酒的主要原料,麦汁的制备决定了啤酒的种类和质量,并直接影响到啤酒生产工艺与成品质量,因此在啤酒生产过程中需要不断优化麦汁制备工艺,形成优良的麦汁色度。麦汁的制备工艺主要包括麦芽制备、麦芽粉碎、糖化、麦汁煮沸沉淀、麦汁过滤与主发酵等步骤,其中糖化工艺会对啤酒麦汁的色度与品质造成影响。因此,需控制好麦芽质量及其粉碎度、糖化温度、淀粉酶pH值、糖化醪浓度等因素,并进一步优化糖化工艺参数,为呈现更好的啤酒麦汁色度奠定坚实的基础。基于此,本文研究糖化工艺对啤酒麦汁色度的影响,并提出啤酒麦汁制备中糖化工艺的优化措施,以提高啤酒麦汁的色度,促进啤酒酿造工艺的优化,推动啤酒行业的高质量发展。     

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。     

糖化工艺调整对麦汁隆丁区分的影响

本文从麦汁制造过程中影响啤酒泡持的因素着手,通过检测麦汁可溶性氮中的高、中、低分子量的含氮比例,阐述通过优化糖工艺来控制麦汁隆丁区分在合理范围     

糖化工艺参数对膨化大米辅料麦汁过滤时间的影响

以辅料含量、加水倍数、50℃蛋白质休止时间、63℃保温时间和70℃保温时间5因素进行5水平二次旋转正交组合试验设计,研究了膨化大米辅料酿造啤酒的外加酶糖化工艺参数对麦汁过滤速度的影响.结果表明,最佳糖化工艺参数为:辅料含量为45.6%～47.2%,料水比为1∶5.0～1∶5.1,50℃蛋白质休止时间为52.9～53.5 min,63℃糖化时间为43.1～44.5 min,70℃糖化时间为31.2～31.9 min.(孙悟)     

膨化大米辅料酿造啤酒中糖化工艺参数对麦汁还原糖含量的影响

在100L规模上,通过五因素五水平二次旋转正交组合实验设计,探讨了膨化大米辅料酿造啤酒的外加酶糖化工艺参数对麦汁还原糖含量的影响规律,得出最佳的糖化工艺参数。      

糖化用水的水质对麦汁中草酸含量的影响

讨论了糖化用水的水质以及外加钙(Ca2 )、外加酸调节pH等水处理方式对麦汁中草酸含量的影响。麦汁中草酸量随着糖化用水总硬度的增加而降低,糖化用水中Ca2 浓度(Ca2 )达到80～100mg/L时,麦汁中大部分草酸被沉淀。使用磷酸和盐酸对麦汁草酸含量影响不明显;使用乳酸调pH,草酸含量有明显的增加。     

糖化用水的水质对麦汁中草酸含量的影响

讨论了糖化用水的水质以及外加钙（Ca2+）、外加酸调节pH等水处理方式对麦汁中草酸含量的影响。麦汁中草酸量随着糖化用水总硬度的增加而降低,糖化用水中Ca2+浓度（Ca2+）达到80～100mg/L时,麦汁中大部分草酸被沉淀。使用磷酸和盐酸对麦汁草酸含量影响不明显;使用乳酸调pH,草酸含量有明显的增加。      

糖化工艺对麦汁缓冲性影响的研究

在相同原料、料液比及相同糖化用水pH下,通过改变糖化投料温度、蛋白质休止温度及两温度下的作用时间,研究糖化工艺参数对麦汁中缓冲物质含量及缓冲性能的影响。研究结果表明,投料温度和蛋白质休止温度对麦汁中可滴定酸、磷酸盐、α-氨基氮及缓冲容量均有不同程度的影响,各实验温度下制得麦汁中缓冲物质含量及缓冲容量均大于对照;通过对A(投料温度)、B(保温时间)、C(蛋白质休止温度)及D(蛋白质休止时间)四因素正交实验结果的数据分析,得出影响可滴定酸、磷酸盐含量、α-氨基氮含量、缓冲容量的主次顺序分别为A>D>B=C、C>A>B>D、A>B>C>D、A>D>B>C,可获得最大缓冲容量的工艺为35℃投料下保温30min,53℃下蛋白质休止90min。     

响应面法优化麦汁糖化工艺条件

以大麦芽、小麦芽为原料,麦汁浸出物收得率为评价指标,在单因素试验基础上,利用响应面法对麦汁糖化工艺进行优化研究。结果表明,最佳的糖化工艺为小麦芽添加量为42.0%,水料比为4∶1（mL∶g）,37 ℃投料保温10 min,52 ℃糖化保温45 min,65 ℃糖化保温68 min,78 ℃保温10 min。在此优化糖化工艺条件下,测得麦汁浸出物得率为79.63%,比未优化前提高8.2%。麦汁糖化液中α-氨基酸态氮含量为272.01 mg/L,还原糖含量为9.14 g/100 mL,可溶性氮含量为1.41 g/L。     

小黑麦啤酒糖化工艺的探讨

首次采用了小麦与黑麦属间异源多倍体杂交品种——小黑麦作为酿造啤酒原料。与传统啤酒大麦原料相比 ,小黑麦不仅淀粉酶活性及蛋白质含量高 ,八种必需氨基酸平衡 ,而且产量高 ,种植费用低 ,可降低原料价格。本试验对小黑麦糖化工艺进行了探讨 ,确定糖化主要技术参数 ,麦汁质量符合酿造啤酒标准。     

Changes in the Concentrations of the Polyphenolic Constituents of Sorghum during Malting and Mashing

Sorghum varieties differed widely in their content of polyphenolic compounds. The concentrations of all phenolic compounds increased several-fold during malting and the degree of increase differed with variety. The concentration of polyphenols extracted in wort was dependent, to a great extent, on the temperature of mashing.     

Vitamins in brewing: the impact of wort production on the thiamine and riboflavin vitamer content of boiled sweet wort

Wort production contains a number of processing steps that are aimed at the optimal extraction of nutrients from malt, including vitamins. This research revealed that the different wort production processing steps imposed different influences on the thiamine and riboflavin vitamer content of the final sweet wort. These vitamins play vital roles within yeast metabolism, where they act as enzyme cofactors. As such thiamine vitamers play a crucial role in many decarboxylating enzymes, while riboflavin vitamers play an integral role in energy production and redox maintenance. While mashing releases valuable starch into the liquor, both thiamine and riboflavin are also extracted. The extraction of these vitamins is the greatest at 65°C and is indirectly linked to the amylase activity. When the starches are broken down during mashing, the thiamine and riboflavin vitamers are gradually released into the mash liquor. The boiling and trub removal (whirlpool) processes impose losses in both vitamins owing to the high temperatures exhibited during these stages. While hop pellets were shown to contribute a small proportion of the vitamers studied, the use of kettle finings caused a significant reduction in both thiamine and riboflavin vitamers. Copyright © 2014 The Institute of Brewing & Distilling     

QUANTITATIVE ANALYSIS OF PURINE NUCLEOSIDES AND FREE BASES IN WORT AND BEER

Low molecular mass compounds containing purine or indole groups exhibit adsorption-based retention characteristics when chromatographed on high performance size exclusion chromatography supports (Superose 12 and Superdex 75). Exploitation of this phenomenon enabled the development of a method for the quantitative analysis of purine nucleosides and free bases in wort and beer. Using this technique, a survey of 18 commercial beers showed the following range of variation of concentrations of these compounds: guanosine + deoxyguanosine 19–110 mg/L, adenosine + deoxyadenosine 3–43 mg/L, xanthine 1–41 mg/L, guanine < 1–11 mg/L and adenine < 1–7 mg/L. Analysis of wort and beer from a commercial brewery demonstrated a decline in both adenine and guanine and an increase in xanthine during the course of a typical fermentation.     

Preparation of a Low Carbohydrate Beer by Mashing at High Temperature with Glucoamylase

A malt grist, supplemented with glucoamylase (1,4-α-D-glucan glucohydrolase, EC 3.2.1.3), was mashed isothermally at 70°C to produce wort with a real fermentability of over 87% and beer with a residual carbohydrate content of less than 0.75% w/v at an original gravity of 42°S. The effects of varying mash pH, calcium content, glucoamylase addition rate and mash conversion time were investigated. The process was effective even with undermodified malt. Pilot scale brewing trials shozved no adverse effect on beer foam quality when the glucoamylase preparation had a specified range of protease side-activity. The process has the advantage of ensuring glucoamylase inactivation during wort boiling while being shorter than the alternative of enzyme treatment of wort prior to boiling.     

麦芽中SOD活性与麦汁还原力的关系以及糖化温度对它们的影响

研究了11种进口麦芽和18种国产麦芽中超氧化物歧化酶(SOD)活性的差异以及与协定麦汁还原力之间的关系。以甘啤-3号麦芽为对象,采用7种恒温糖化工艺考察了糖化温度对2者的影响。结果表明,不同品种麦芽中,SOD的差异比较明显(1205.6～2126.0U/g),而且麦芽的SOD活性与协定麦汁的还原力之间存在显著的正相关性(相关系数r=0.898,P<0.01);SOD活性随着糖化温度的升高而逐渐降低,55℃恒温糖化60min后有53.22%的酶活残存;当糖化温度升高到65℃时,SOD的活性大幅度下降,30min后仍有25.45%的酶活残存;糖化温度为70℃和80℃时SOD下降到极低的活性;麦汁的还原力随着糖化温度的升高而升高,80℃恒温糖化100min后麦汁的还原力高达3.75mmol/mL。     

糖化温度对7°P麦汁阿拉伯木聚糖、β-葡聚糖的影响研究

小麦是良好的啤酒酿造原料,在我国种植面积广泛,价格较低,品种多,富含蛋白质、淀粉。本文设计添加10％小麦芽进行糖化,研究不同糖化温度和糖化时间对7^oP麦汁理化指标的影响。实验结果表明,52℃15mm、63℃110min、72℃20min、78℃过滤糖化工艺中,7^oP麦汁阿拉伯木聚糖含量最多,为1034．33mg／L;52℃15min、63℃100min、72℃20min、78℃过滤糖化工艺中,β-葡聚糖含量最高,为72．96mg／L。当阿拉伯木聚糖产生919．33mg／L、β-葡聚糖产生两为72．96mg／L时,7^oP麦汁的粘度最大,此时,过滤速率为81．52mL／30min。