啤酒brewing practices date from at least 7000 BCE and maybe even to the advent of agriculture because most cereals can instantly ferment upon exposure to airborne yeasts.
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The code of the Babylonian king Hammurabi (rule 1792 to 1750 BCE), whose laws 108 to 111 regulate beer sales, indicates that people have been concerned about protecting beer quality via legislation for millennia.
For instance, the Bavarian “Reinheitsgebot” (“Purity Law”) of 1516, which is usually regarded the world’s oldest still functional—along with modifications—food regulation permits only water, barley, and hops as ingredients for brewing beer (where the barrels were confiscated as a penalty for transgression).
在一项新研究中，啤酒科学已经达到了全新的亚博老虎机网登录水平。来自德国的研究人员使用先进的分析方法来披露全球获得的商业啤酒的代谢复杂性（六个不同的分子）。
The study was reported recently in the journalFrontiersin Chemistry。
巨大的化学复杂性
啤酒是巨大化学复杂性的一个例子。而且，由于最近的分析化学方法的改进，与不断增长的视频显示技术中正在进行的革命相比，我们可以以前所未有的细节来揭示这种复杂性。
Philippe Schmitt-Kopplin，慕尼黑技术大学综合食品平台的研究对应作者兼教授
“Today it’s easy to trace tiny variations in chemistry throughout the food production process, to safeguard quality or to detect hidden adulterations” Schmitt-Kopplin补充说，他还是慕尼黑赫尔姆霍尔茨中心分析生物地球化学研究部门的负责人。
Schmitt-Kopplin和他的合作者利用了两种强大的技术 - 效果液相色谱液压杆螺旋体飞行时间质谱（UPLC-TOF-MS）和直接输注傅立叶转化离子转基因环流共振质谱法（DI-FTICR MS） - 披露在欧洲，东亚，非洲，美国和拉丁美洲酿造的467种啤酒中，有467种啤酒的全代代谢产物范围。
这些啤酒包括工艺品和修道院啤酒，最高发酵的啤酒，啤酒和大麦作为发酵淀粉的来源，或大麦加玉米（玉米），大米或小麦的来源；这些方法表现出互补的优势。
Chemical diversity has been unraveled directly by DI-FTICR-MS throughout all beers, predicting chemical formulas for the metabolite ions present in them.
Then, the researchers applied UPLC-ToF-MS to a subset of 100 beers to examine the outcomes with resolution on the potential isomers. UPLC-ToF-MS involves using chromatography to initially isolate ions with similar masses and fragmentation of the mass ions to daughter ions, thereby enabling the accurate molecular structure to be predicted.
代谢物在“化学空间”中定位在“化学空间”中，每种反应都与一个或多个其他反应相关联，例如，将硫酸盐，羟基，甲氧基或糖基添加到分子主链中，或转化不饱和的键入饱和键。
This enabled a reconstruction of a metabolite network resulting in the final product, comprising almost a hundred steps with a starting point in molecules from the original cereals, produced from the amino acid tryptophan. The products acquired from these are the secondary metabolites, which are exclusive to every cereal.
Powerful Method for Quality Control
Our mass spectrometry method, which takes only 10 minutes per sample, should be very powerful for quality control in food industry and set the basis of novel molecular markers and non-targeted metabolite profiles needed in foodstuff inspection。
Philippe Schmitt-Kopplin，慕尼黑技术大学综合食品平台的研究对应作者兼教授
The researchers discovered nearly 7700 ions exhibiting exclusive masses and formulas, such as phenolics, nucleotides, peptides, lipids, carbohydrates, phosphates, and organic acids. Of these, almost 80% are not yet explained in chemical databases. Since there are possibilities of each formula covering up to 25 various molecular structures, this amounts to tens of thousands of special metabolites.
Here we reveal an enormous chemical diversity across beers, with tens of thousands of unique molecules. We show that this diversity originates in the variety of raw materials, processing, and fermentation。
Stefan Pieczonka, Study First Author and PhD Student, Technical University of Munich
Pieczonka continued, “然后通过所谓的分子复杂性扩增’Maillard reaction’between amino acids and sugars which also gives bread, meat steaks, and toasted marshmallow their’roasty’味道。”
“鉴于其对粮食质量，风味的重要性以及新颖的健康生物活性分子的发展，这种复杂的反应网络是我们研究的激动人心的重点,” added Pieczonka.
期刊参考：
Pieczonka, S. A.,et al。（（2021) On the Trail of the German Purity Law: Distinguishing the Metabolic Signatures of Wheat, Corn, and Rice in Beer。Frontiers in Chemistry。doi.org/10.3389/fchem.2021.715372.
Source:https://www.frontiersin.org/