PDF(Pubmed)
Abstract：
To reduce unwanted fat bloom in the manufacturing and storage of chocolates, detailed knowledge of the chemical composition and molecular mobility of the oils and fats contained is required. Although the formation of fat bloom on chocolate products has been studied for many decades with regard to its prevention and reduction, questions on the molecular level still remain to be answered. Chocolate products with nut-based fillings are especially prone to undesirable fat bloom. The chemical composition of fat bloom is thought to be dominated by the triacylglycerides of the chocolate matrix, which migrate to the chocolate\'s surface and recrystallize there. Migration of oils from the fillings into the chocolate as driving force for fat bloom formation is an additional factor in the discussion. In this work, the migration was studied and confirmed by MRI, while the chemical composition of the fat bloom was measured by NMR spectroscopy and HPLC-MS, revealing the most important triacylglycerides in the fat bloom. The combination of HPLC-MS with NMR spectroscopy at 800 MHz allows for detailed chemical structure determination. A rapid routine was developed combining the two modalities, which was then applied to investigate the aging, the impact of chocolate composition, and the influence of hazelnut fillings processing parameters, such as the degree of roasting and grinding of the nuts or the mixing time, on fat bloom formation.
摘要：
为了减少巧克力制造和储存过程中不必要的脂肪堆积，需要详细了解所含油脂的化学成分和分子流动性。虽然巧克力产品上脂肪的形成已经研究了几十年，关于预防和减少它，分子水平上的问题仍然有待回答。具有基于坚果的馅料的巧克力产品特别容易产生不期望的脂肪起霜。据认为，脂肪霜的化学成分主要由巧克力基质的三酰甘油酯组成，它迁移到巧克力的表面并在那里重结晶。油从填充物中迁移到巧克力中作为形成脂肪起霜的驱动力是讨论中的另一个因素。在这项工作中,通过MRI研究并证实了迁移，虽然通过NMR光谱和HPLC-MS测量了脂肪霜的化学成分，揭示了脂肪中最重要的三酰基甘油酯。HPLC-MS与800MHz的NMR光谱的组合允许详细的化学结构测定。开发了一种结合两种模式的快速例程，然后用于研究衰老，巧克力成分的影响，以及榛子馅料加工参数的影响，如坚果的烘烤和研磨程度或混合时间，关于脂肪绽放的形成。
