Laboratoire de Physique des Systèmes Complexes, Université Picardie Jules Verne, 33 rue S(t)Leu, 80039 Amiens cedex, France.
Laboratoire de Physique des Systèmes Complexes, Université Picardie Jules Verne, 33 rue S(t)Leu, 80039 Amiens cedex, France.
Food Chem. 2018 Nov 30;267:187-195. doi: 10.1016/j.foodchem.2017.09.006. Epub 2017 Sep 5.
Raman spectroscopy was used to characterize the polymorphs and liquid state of anhydrous milk fat, with emphasis placed on the thermal evolution of the ester carbonyl stretching modes (1800-1700cm) and the comparative study of the Raman-active CC (1660cm) and CH (3000-2700cm) vibrational modes. Specific Raman signatures in the crystalline phase were found and attributed to the coexistence of two groups of triglycerides. This was confirmed using differential scanning calorimetry and X-ray diffraction methods. In the ester carbonyl band, the effect of changing temperature on both the number of modes and new defined intensity ratios was studied and enabled polymorph discrimination. CH stretching signals increased with polymorph stability, indicating the dominance of antisymmetric CH methylene vibrations as the anhydrous milk fats crystal lattice became more ordered. The change in intensity of the CH stretching bands as a function of temperature was used to probe the order-disorder transition.
拉曼光谱用于对无水乳脂的多晶型物和液相进行特征分析，重点研究酯羰基伸缩模式（1800-1700cm）的热演化以及拉曼活性 CC（1660cm）和 CH（3000-2700cm）振动模式的比较研究。在结晶相中发现了特定的拉曼特征，并将其归因于两组甘油三酯的共存。这一点通过差示扫描量热法和 X 射线衍射法得到了证实。在酯羰基带中，研究了温度变化对模式数量和新定义的强度比的影响，从而实现了多晶型物的鉴别。随着多晶型物稳定性的增加，CH 伸缩信号增加，表明随着无水乳脂晶格变得更加有序，反式 CH 亚甲基振动占主导地位。随着温度的变化，CH 伸缩带的强度变化用于探测有序-无序转变。
