John Warren A, Kumari Neha, Böttcher Nina L, Koffi Kouame Jean, Grimbs Sergio, Vrancken Gino, D'Souza Roy N, Kuhnert Nikolai, Ullrich Matthias S
Department of Life Sciences and Chemistry, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany.
Barry Callebaut Belgium N.V., Aalstersestraat 122, 9280 Lebbeke-Wieze, Belgium.
Food Res Int. 2016 Nov;89(Pt 1):764-772. doi: 10.1016/j.foodres.2016.10.011. Epub 2016 Oct 12.
The fermentation of cocoa beans is essential for the generation of flavour precursors that are required later on to form the flavour components of chocolate. From the many different precursors that are generated, oligopeptides and free amino acids comprise a significant proportion as some of them form Maillard reaction products during the roasting process. Therefore, the diversity of peptides is an important contributing factor to the quality of a fermentation which is in turn controlled by proteolytic activity within the cocoa bean, and is driven by changes in the presence of fermentation by-products as a result of microbial activity outside the bean. Being able to control proteolytic activity within the bean using only the presence of fermentation by-products would prove a valuable tool in the study of these proteases and the processing of cocoa storage proteins. Thus, this tool would help elucidate key mechanisms that generate the components responsible for flavour. In this study, we describe an artificial fermentation system, free from microbial activity, which is able to replicate proteolytic degradation of protein as well as to generate similar peptide fragments as seen during a commercial fermentation. It was also found that acidification is a main contributor to protein degradation.
可可豆的发酵对于风味前体的生成至关重要,这些风味前体在后续过程中会形成巧克力的风味成分。在生成的众多不同前体中,寡肽和游离氨基酸占了很大比例,因为其中一些在烘焙过程中会形成美拉德反应产物。因此,肽的多样性是影响发酵质量的一个重要因素,而发酵质量又由可可豆内的蛋白水解活性所控制,并且受到豆外微生物活动导致的发酵副产物存在变化的驱动。仅利用发酵副产物的存在来控制豆内的蛋白水解活性,将成为研究这些蛋白酶和可可储存蛋白加工过程的一个有价值的工具。因此,这个工具将有助于阐明产生风味相关成分的关键机制。在本研究中,我们描述了一种无微生物活动的人工发酵系统,该系统能够复制蛋白质的蛋白水解降解过程,并产生与商业发酵过程中所见类似的肽片段。研究还发现,酸化是蛋白质降解的主要因素。