In situ observation of transformation pathways of polymorphic forms of 1,3-dipalmitoyl-2-oleoyl glycerol (POP) examined with synchrotron radiation X-ray diffraction and DSC

摘要: POP (1,3-dipalmitoyl-2-oleoyl glycerol), a major triacylglycerol component of vegetable and animal fats found in chocolate, fat spread, other edible fats, crystallizes seven polymorphic forms: α, γ, δ, β′2, β′1, β2, β1. The crystallization transformation pathways the polymorphs are influenced by many factors. In present work, we studied influence rates cooling heating on POP. rate (heating) was changed from 15 to 2, 1, 0.5 °C min−1 (15 0.5, 0.1 min−1). processes were examined with differential scanning calorimetry (DSC) synchrotron radiation X-ray diffraction (SR-XRD). results indicated that more stable forms formed higher quantity when slowly cooled heated, whereas less occurred at heating. Specifically, α γ directly obtained min−1. β′ or β did not occur even min−1, transformed transformations either solid-state melt-mediation largely rates. We discuss considering differences activation free energies for forms, which may determine heating-rate-dependent pathways.