Effects of added enzymes on sorted,unsorted and sorted-out barley: A model study on realtime viscosity and process potentials using rapid visco analyser

Barley sorting is an important step for selecting grain of required quality for malting prior to brewing. However, brewing with unmalted barley with added enzymes has been thoroughly proven, raising the question of whether traditional sorting for high quality malting-barley is still necessary. To gain more insight on this, we examine realtime viscosity of sorted-out and unsorted barley during downscaled mashing with added enzymes in comparison with malting quality sorted barley. A rapid visco analyser was used to simulate brewery mashing process at lab scale together with two commercial enzymes (Ondea^®-Pro and Cellic^®-CTec2). During downscaled mashing, viscosity profile of sorted-out barley was markedly different from others, irrespective of enzyme type, whereas a small difference was observed between the sorted and un-sorted barley. Furthermore, whilst sorted-out barley generated lowest sugar-concentration, unsorted and sorted barley resulted in higher sugar-content, regardless of the enzyme used. In terms of filterability, the Ondea^®-Pro treatment resulted in significantly lower-turbidity and smaller particle-size compared to Cellic^®-CTec2; however, this effect was observed in sorted and unsorted barley but not in sorted-out barley. Consequently, we find that unsorted barley demonstrates great potential for brewing with added enzymes and its use may help to improve sustainability of the brewing process.     

啤酒中人参皂甙含量的测定方法初探

对啤酒中人参皂甙的测定方法进行了初步探讨。实验证明,采用正丁醇浸提,香草醛、硫酸显色并在544nm处测定吸光度的方法测定啤酒中人参皂甙的含量效果较好,实验回收率达99%以上。     

壳聚糖对啤酒中嘌呤的吸附性能

以不同浓度的壳聚糖加入啤酒中,吸附以高氯酸水解出的嘌呤碱基,用高效液相色谱法(HPLC)测定吸附前后4种嘌呤碱基量,结果显示:壳聚糖可以有效吸附啤酒中的嘌呤碱基,降低啤酒中的嘌呤含量。     

甘蔗渣纤维素固定化木瓜蛋白酶及其应用研究

匀浆状甘蔗渣纤维素用NaOH活化后，顺次经过高碘酸钠、尿素、甲醛处理，成为高反应性固定化酶载体，可用于木瓜黄蛋白酶的固定化，其酶蛋白的结合量与甲醛处理时间、酶固定时间、溶液酶浓度等有关，甲醛处理最适时间为14h，酶固定8h后，载体结合酶量趋向稳定；溶液酶最佳浓度范围为1－2．0mg/ml粗酶，固定化酶活力回收达34．5％，半衰期35天，固定化酶和溶液酶的Km值（底物酪蛋白，w/v,%)分别为0．12％和0．26％；固定化酶和溶液酶的最适PH分别为PH8．0和PH8．5，二者的最适温度均为60－70℃。固定化酶和溶液酶一样有底物抑制现象，固定化酶在6mol/L脲中处理6h活力趋向稳定，其活力为原有活力的46．75，用固定化酶处理啤酒，啤酒浊度下降了2－9．25倍，蛋白质含量下降了78．8％，冷藏120天，处理啤酒无冷混浊现象发生，同时啤酒原有风味和其它理化指标保持不变。     

影响啤酒稳定性的因素及预防

本文探讨了生产实践中影响啤酒稳定性的因素和预防措施。     

啤酒生产生命周期评价研究

利用生命周期评价方法对啤酒生产进行案例分析，全面评价啤酒生产资源、能源消耗以及对环境的排放，并对由此产生的环境影响潜值进行量化估算。把啤酒生产系统分成酿造、包装和蒸汽生产3个子系统进行评价。结果显示，啤酒生产环境潜在影响大小依次是富营养化、全球变暖、粉尘和烟尘、酸化和工业固废排放;各子系统对环境潜在影响大小依次是酿造、蒸汽生产和包装。根据评价结果，提出对酿造过程和蒸汽生产过程进行技术改造及相关配套设施的建设来降低啤酒生产对环境的影响。     

挤压膨化大米辅料麦汁和啤酒的糖类组分分析

用液相色谱技术对挤压膨化大米啤酒辅料对应的麦汁、啤酒的糖类组分进行了测定，表明：膨化大米辅料麦汁中麦芽糖含量明显高于未膨化大米辅料麦汁，未膨化大米辅料麦汁中葡萄糖、果糖、蔗糖和麦芽三糖的含量均略高于膨化大米辅料麦汁，膨化和未膨化大米辅料对应的啤酒中没有检测出果糖、葡萄糖、蔗糖、麦芽糖，只检测出微量的麦芽三糖。     

Current perspectives on the role of enzymes in brewing

The brewing of beer is a very traditional process, based upon a complex endogenous enzymology occurring during the malting of grain, mashing of grist and fermentation. The relevant cereal-derived enzymes that are involved are reviewed. It is likely that the production of alcoholic beverages in breweries in the projected future will assume different paradigms, procedures which are already realistic for the production of flavoured alcoholic beverages (malternatives) and “near-beer” drinks (happoshu and other beer-like beverages) in Japan. A range of exogenous enzymes—such as glucanases, acetolactate decarboxylase and prolyl endopeptidase—are available for enhancement of the existing brewing process.     

木素制啤酒非生物稳定剂的研究

利用木素的超分子特性,并通过改性而使其表面基团与高分子蛋白质作用,进而将其絮凝沉淀除去,从而提高啤酒的非生物稳定性。主要对制浆废液中木素的分离、木素的改性条件及措施、木素对啤酒非生物稳定性的影响进行了探讨。研究结果表明,啤酒加入木素后,啤酒澄清速度加快,过滤后,啤酒色度较未用木素的大约下降1.0 EBC单位;浊度显著下降,证明木素有明显的提高非生物稳定性的作用。     

适合用于酿造啤酒的小黑麦品种初步筛选

为探讨用小黑麦麦芽代替大麦麦芽酿造小黑麦啤酒的可能性,以小黑麦6个品种(系)为材料,研究小黑麦酿造啤酒的主要理化指标、水敏感性以及两种焙燥工艺下麦芽质量。结果表明,小黑麦品种东农95-6654、北联7号的理化指标符合二棱大麦优级标准;焙燥工艺为45℃6h→55℃5h→65℃3h→76℃3h时小黑麦麦芽的α-氨基氮含量、麦芽糖化力、麦芽浸出率等指标与啤酒生产上用大麦芽相似。