Lankhorst Peter P, Voogt Benjamin, Tuinier Remco, Lefol Blandine, Pellerin Patrice, Virone Cristiana
DSM Biotechnology Centre , P.O. Box 1, 2600 MA Delft, The Netherlands.
DSM AHEAD, ACES , Geleen, P.O. Box 18, 6160 MD Geleen, The Netherlands.
J Agric Food Chem. 2017 Oct 11;65(40):8923-8929. doi: 10.1021/acs.jafc.7b01854. Epub 2017 Oct 3.
Young wines are supersaturated in potassium bitartrate, which induces rather uncontrolled crystallization processes. Delayed crystallization may occur even after bottling of the young wines, which is undesirable because it gives rise to a visual defect in the wine. Colloids such as mannoproteins, metatartaric acid, and carboxymethylcellulose are available on the market and may be added to delay crystallization. It has been a matter of debate whether such hydrocolloids prevent nucleation, growth of crystals, or both. It was the objective of this investigation to study the crystallization event by a new approach using dynamic light scattering and to clarify the mode of action of these hydrocolloids. To achieve this, model solutions and standardized wines were enriched with potassium bitartrate (KHT) to trigger crystallization. In this way, it was possible to distinguish between the influence of the hydrocolloids on nucleation and on crystal growth. It was found that the hydrocolloids do not prevent KHT nucleation. Instead, these compounds delay or even arrest the outgrowth of the crystals to a macroscopic, visual size.
年轻葡萄酒中的酒石酸氢钾处于过饱和状态，这会引发相当难以控制的结晶过程。即使在年轻葡萄酒装瓶后，也可能会出现延迟结晶的情况，这是不理想的，因为它会导致葡萄酒出现视觉缺陷。诸如甘露糖蛋白、偏酒石酸和羧甲基纤维素等胶体在市场上有售，可以添加它们来延迟结晶。这些水胶体是阻止成核、晶体生长，还是两者都阻止，一直存在争议。本研究的目的是通过一种使用动态光散射的新方法来研究结晶过程，并阐明这些水胶体的作用方式。为了实现这一目标，在模型溶液和标准葡萄酒中添加酒石酸氢钾（KHT）以引发结晶。通过这种方式，可以区分水胶体对成核和晶体生长的影响。研究发现，水胶体不会阻止KHT成核。相反，这些化合物会延迟甚至阻止晶体生长到肉眼可见的宏观尺寸。
