The objective of this work was to identify the effects that milk phospholipids (PL) have on crystallization of anhydrous milk fat (AMF). Three mixtures were prepared by adding 0%, 0.01%, and 0.1% PL to AMF. Each mixture was crystallized for 90 min at 24, 26, and 28 °C. The solid fat content was measured as a function of time and fitted to the Avrami equation. Melting point, thermal behavior, viscoelastic properties, and crystal morphology were all measured at 90 min. All assays were repeated, as well as hardness, after being stored at 5 °C for 48 hours. Samples containing PL showed slower crystallization as concentration increased especially at higher temperatures (26 and 28 °C). The addition of PL caused a difference in crystal morphology resulting in visibly larger crystals at 90 min. The elasticity and hardness at 90 min were influenced by the addition of PL at 24 °C with lower values obtained in samples with PL compared to the AMF alone. No differences in hardness nor in elasticity was observed for samples crystallized at 26 and 28 °C. A decrease in melting enthalpy was observed in samples with PL indicating a reduction in crystallization at all temperatures, which was supported by crystal morphology.

中文翻译：

---

通过添加乳制品磷脂来延缓结晶

这项工作的目的是确定乳磷脂（PL）对无水乳脂（AMF）结晶的影响。通过向AMF中添加0％，0.01％和0.1％PL来制备三种混合物。每种混合物在24、26和28°C结晶90分钟。固体脂肪含量作为时间的函数进行测量，并与Avrami方程拟合。熔点，热行为，粘弹性和晶体形态均在90分钟时测量。在5°C下储存48小时后，重复所有测定以及硬度测定。包含PL的样品显示出随着浓度增加而结晶的速度变慢，尤其是在较高温度（26和28°C）下。PL的添加引起晶体形态的差异，导致在90分钟时明显更大的晶体。90分钟时的弹性和硬度受24°C下PL含量的影响，与单独使用AMF相比，PL样品中的PL值更低。对于在26和28°C结晶的样品，未观察到硬度或弹性的差异。在PL样品中观察到熔融焓降低，这表明在所有温度下结晶的减少，这由晶体形态支持。