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目的研究和调节丙氨酰谷氨酰胺冻干样品的结晶度及粒度均一性,为冻干工艺研究和产业化奠定基础。方法用扫描电镜、X-射线粉末衍射、差示扫描量热、热重分析和冻干实验分别研究了快速降温预冻和多次变温退火预冻对丙氨酰谷氨酰胺冻干样品结晶度及结晶粒度的影响。结果扫描电镜结果揭示了快速降温预冻后丙氨酰谷氨酰胺冻干样品的颗粒细小,结晶度低,但经多次变温退火处理后,冻干样品结晶粒度均一,结晶度高;X-射线粉末衍射结果和差示扫描量热分析结果均说明多次变温退火预冻方式较快速降温预冻方式更有利于丙氨酰谷氨酰胺形成结晶粒度均一、晶体缺陷少、结晶度高的冻干样品;热重分析的实验结果表明,经过快速降温预冻再冻干的丙氨酰谷氨酰胺样品热稳定性差;多次变温退火预冻再冻干的丙氨酰谷氨酰胺样品热稳定性好。结论最终的真空冻干实验证明,多次变温退火预冻不仅提高了丙氨酰谷氨酰胺冻干样品的质量和冻干效率,节约了成本,还达到生产节能降耗的最终目的。
Objective To study and adjust the crystallinity and particle size uniformity of the alanyl glutamine freeze-dried samples, and lay a foundation for the research of freeze-drying technology and industrialization. Methods The crystallinity of freeze-dried samples of alanyl glutamine was studied by scanning electron microscopy, X-ray powder diffraction, differential scanning calorimetry, thermogravimetric analysis and freeze-drying experiments, respectively. And the impact of grain size. Results The results of scanning electron microscopy revealed that the freeze-dried alanyl-glutamine samples after freeze-thawing were small in size and low in crystallinity. However, the samples were homogeneously crystallized and the crystallinity was high after multiple temperature-controlled annealing. X- Ray powder diffraction results and differential scanning calorimetry results show that the multi-temperature annealing prefreezing method is more conducive to the formation of alanylglutamine uniform crystalline grain size, less crystal defects, high crystallinity of the frozen The results of thermogravimetric analysis showed that the alanylglutamine samples after pre-freezing and then freeze-drying were poor in thermal stability. The samples of alanylglutamine with multiple-temperature annealing pre-freeze and freeze-dried were thermally stable Good sex. Conclusions The final vacuum freeze-drying experiment proves that pre-freezing by multiple temperature annealing not only improves the quality and lyophilization efficiency of the alanyl glutamine lyophilized sample, saves the cost, but also achieves the ultimate goal of saving energy and reducing consumption.