Experimental and numerical investigations on the effects of cavitation and flow-related collisions on aggregate formation and loss of activity after cell disruption in the high-pressure homogeniser using the model systems lipase or beta-lactoglobulin as e

使用模型系统脂肪酶或 β-乳球蛋白作为实验和数值研究，研究空化和流动相关碰撞对高压匀浆器中细胞破碎后聚集体形成和活性丧失的影响。

• 批准号: 425332181
• 负责人: Professorin Dr.-Ing. Heike Karbstein
• 金额: --
• 依托单位: Bereich I: Lebensmittelverfahrenstechnik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/425332181?language=en
• 关键词: Experimental; numerical; investigations; effects; cavitation

Biotechnologically obtained enzymes or protein isolates from plant sources are often obtained by cell disruption. High pressure homogenisers are used for this purpose. In high-pressure homogenization, an extreme acceleration of the medium generates stresses, which are responsible for high cell disintegration rates. A side effect is often cavitation, which creates gas/liquid (bubbles) and/or solid/liquid (abrasion particles) interfaces. This research proposal concentrates on the loss of enzyme activity and the denaturation and aggregation of proteins, for which according to literature a boundary and/or shear-induced unfolding of the three-dimensional structure followed by aggregation in the flow is held responsible. The basic working hypothesis of this project is the assumption that structural losses of enzyme or protein activity can be reduced if cavitation in disruption units of high-pressure homogenisers is largely avoided and the collision frequency in the out-flow chamber is efficiently reduced. Methods for this are the application of back pressure and feeding of a diluting mixed stream directly into the outflow chamber behind the narrowest cross-section, so that high mixing efficiencies can be achieved locally. In the proposal, numerical flow simulations of such novel simultaneous homogenizing and mixing (SHM) units will be performed and evaluation methods for predicting cavitation and collision rates as a function of geometry and process parameters will be developed and verified by accompanying experiments. In cooperation with other subproject partners in the SPP, stress histories and expected aggregation rates are predicted. This leads to design strategies for the preservation of functionality of enzymes and proteins obtained by cell disruption in a high-pressure homogeniser.

通过生物技术从植物来源获得的酶或蛋白质分离物通常是通过细胞破碎获得的。高压均质机用于此目的。在高压均质化中，介质的极度加速会产生应力，从而导致高细胞崩解率。副作用通常是空化，它会产生气体/液体（气泡）和/或固体/液体（磨损颗粒）界面。该研究提案集中于酶活性的丧失以及蛋白质的变性和聚集，根据文献，边界和/或剪切诱导的三维结构展开，随后在流动中聚集是造成这种情况的原因。该项目的基本工作假设是，如果很大程度上避免高压均质器破碎单元中的空化并且有效降低流出室中的碰撞频率，则可以减少酶或蛋白质活性的结构损失。其方法是施加背压并将稀释的混合流直接送入最窄横截面后面的流出室，从而可以局部实现高混合效率。在该提案中，将对这种新型同时均质和混合（SHM）装置进行数值流动模拟，并将开发预测空化和碰撞率作为几何形状和工艺参数函数的评估方法，并通过随附的实验进行验证。与 SPP 中的其他子项目合作伙伴合作，预测压力历史和预期聚集率。这导致了在高压均质机中通过细胞破碎获得的酶和蛋白质的功能保存的设计策略。