Glucosidase inhibitors: new approaches to malting efficiency

酿造和蒸馏工业对英国经济有着巨大的重要性。他们对农业产生重大影响，因为他们每年使用近200万吨英国种植的大麦（约占作物的三分之一，占100万公顷土地的三分之一），他们为成千上万的人提供就业机会，他们的产品不仅在英国而且在世界上许多国家都很受欢迎。该行业面临着巨大的压力，需要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能力，但也是为了减少废物的产生和转换过程中使用的能源量。基本的转化过程分为四个主要阶段。首先，在酿造过程中，大麦籽粒被浸泡在水里，然后开始发芽。在发芽的谷物中，产生的酶可以将储存在谷物中的淀粉转化为糖。其次，在烧制过程中，谷物被加热以使其干燥，从而停止发芽。第三步，谷物被碾碎，然后与热水混合。在这个捣碎过程中，酶将淀粉转化为糖。最后，将含糖液体沥干，加入酵母。酵母把糖转化为酒精。在将谷物转化为啤酒和威士忌的过程中，一个主要的损失发生在麦芽酿造过程中。一旦酶产生，它们就开始在种子内将淀粉转化为糖，而糖又为小根的生长提供燃料。因此，在捣碎阶段之前，一些淀粉储存丢失，降低了酒精的潜在产量，导致产生不必要的小根。这种损失在淀粉的5%到10%之间。在酿造行业200亿英镑的市场价值背景下，即使麦芽酿造过程中淀粉损失程度的微小减少也会带来巨大的经济效益。由于这种麦芽损失的经济重要性，已经测试了几种不同的防止根生长的方法。然而，由于成本、毒性或对麦芽质量的不利影响，这些都没有在商业上应用。我们已经发现，大麦种子发芽过程中的小根生长和淀粉损失都可以通过施用少量的天然植物产品（称为亚氨基糖）来减少或防止。这些产品有可能减少麦芽的损失而没有不良的副作用。了解它们如何在种子内工作也将提供新的信息，这将有助于开发用于酿造和蒸馏的更好的大麦品种。在这个项目中，我们将在模拟真实麦芽酿造的“微麦芽酿造”系统中测试天然产品，并确定哪些产品适合商业试验。我们将使用生化和分子方法来精确地发现这些产品是如何阻止根的生长和淀粉的损失的。这一信息将使我们能够识别大麦中的基因，这些基因对决定谷物的麦芽品质很重要。为了确保我们的研究与酿造和蒸馏行业的需求相关，我们将定期咨询咨询小组，该小组包括这些行业的专家，以及大麦谷物发芽，植物天然产品和麦芽方面的专家。

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.