Glucosidase Inhibitors: New approaches to malting efficiency

葡萄糖苷酶抑制剂：提高麦芽效率的新方法

• 批准号: BB/I017569/1
• 负责人: David Cook
• 金额: $ 8.6万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FI017569%2F1
• 关键词: Glucosidase; Inhibitors; New; approaches; malting

The brewing and distilling industries are of enormous economic importance to the UK. They have a major impact on farming because they use almost 2M tonnes of UK-grown barley (about one third of the crop, occupying one third of a million hectares of land) every year, they provide employment for tens of thousands of people, and their products are enjoyed not only in the UK but in many countries around the world. There is strong pressure on the industry to increase the efficiency with which barley grain is converted into beer and whisky. This is in part to maintain profitability, but also to reduce the production of waste and the amount of energy used in the conversion process. The basic conversion process occurs in four main stages. First, during malting, the barley grains are soaked in water then allowed to start to germinate. Inside the germinating grain, enzymes are produced that can convert the starch stored in the grain to sugars. Second, during kilning, the grain is heated to dry it out so that germination stops. Third, the grain is milled then mixed with hot water. During this mashing process, the enzymes convert the starch to sugars. Finally, the sugar-containing liquid is drained off and yeast is added. The yeast converts the sugars to alcohol. One of the major losses during the conversion of grain to beer and whisky occurs during malting. As soon as the enzymes are produced, they start to convert starch to sugars inside the seed, and the sugars fuel the growth of rootlets. Thus some of the starch store is lost before the mashing stage, reducing the potential yield of alcohol and resulting in the production of unwanted rootlets. This loss is between 5% and 10% of the starch. In the context of a market value of £20bn for the brewing industry alone, even a small reduction in the extent of starch loss during malting would have huge economic benefits. Because of the economic importance of this malting loss, several different methods to prevent rootlet growth have been tested. However these have not been applied commercially, because of cost, toxicity, or adverse effects on the quality of the malt. We have discovered that both rootlet growth and starch loss in germinating barley seeds can be reduced or prevented by the application of tiny amounts of natural plant products, called iminosugars. These products have the potential to reduce malting losses without undesirable side effects. Understanding how they work inside the seed will also provide new information that will help in developing better varieties of barley for brewing and distilling. In this project we will test natural products in a 'micromalting' system that mimics real malting, and identify which ones are suitable for commercial trials. We will use biochemical and molecular methods to discover precisely how these products prevent the growth of rootlets, and the loss of starch. This information will enable us to identify genes in barley that are important in determining the malting quality of the grain. To ensure that our research is relevant to the needs of the brewing and distilling industries, we will regularly consult an Advisory Panel that includes an expert on these industries, and also experts on barley grain germination, plant natural products, and malting.

酿酒和蒸馏行业对英国具有巨大的经济重要性。它们对农业产生了重大影响，因为它们每年使用近200万吨英国种植的大麦(约占总产量的三分之一，占三分之一的土地)，它们为数万人提供就业机会，而且它们的产品不仅在英国，而且在世界许多国家都能享受到。该行业面临着巨大的压力，要求提高大麦谷物转化为啤酒和威士忌的效率。这在一定程度上是为了保持盈利，但也是为了减少废物的产生和转换过程中使用的能源量。基本转换过程分为四个主要阶段。首先，在制麦过程中，大麦粒被浸泡在水中，然后开始发芽。在发芽的谷物内部，会产生一些酶，可以将储存在谷物中的淀粉转化为糖。其次，在烘烤过程中，谷物被加热以使其干燥，从而停止发芽。第三，将谷物碾碎，然后与热水混合。在这个糖化过程中，酶将淀粉转化为糖。最后，将含糖液体抽干，加入酵母。酵母菌将糖转化为酒精。在将谷物转化为啤酒和威士忌的过程中，主要的损失之一发生在麦芽酿造过程中。一旦产生这些酶，它们就开始将种子内的淀粉转化为糖，这些糖为根的生长提供燃料。因此，一些储存的淀粉在糖化阶段之前就会丢失，降低了酒精的潜在产量，并导致产生不需要的根条。这种损失在淀粉的5%到10%之间。仅酿造行业的市场价值就达200亿GB，即使麦芽过程中淀粉损失的程度略有减少，也会产生巨大的经济效益。由于麦芽损失的经济重要性，已经测试了几种不同的防止小根生长的方法。然而，由于成本、毒性或对麦芽质量的不利影响，这些产品尚未投入商业应用。我们已经发现，发芽大麦种子中的小根生长和淀粉损失都可以通过应用少量的天然植物产品来减少或防止，这种产品被称为亚胺糖。这些产品有可能在没有不良副作用的情况下减少麦芽损失。了解它们在种子内部的作用也将提供新的信息，有助于开发更好的大麦品种，用于酿造和蒸馏。在这个项目中，我们将在模拟真实麦芽的“微麦芽”系统中测试天然产品，并确定哪些适合商业试验。我们将使用生化和分子方法来准确地发现这些产品是如何防止根生长和淀粉损失的。这些信息将使我们能够识别大麦中对决定谷物制麦质量至关重要的基因。为了确保我们的研究与酿造和蒸馏行业的需求相关，我们将定期咨询一个咨询小组，其中包括一名这些行业的专家，以及大麦谷物发芽、植物天然产物和麦芽生产的专家。

项目成果

Cell wall degradation is required for normal starch mobilisation in barley endosperm.

• DOI: 10.1038/srep33215
• 发表时间: 2016-09-13
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Andriotis VM;Rejzek M;Barclay E;Rugen MD;Field RA;Smith AM
• 通讯作者: Smith AM