Polymorphic crystallization and transformation pathways of 1,2-dipalmitoyl-3-oleoyl-rac-glycerol (PPO) during a liquid–solid-liquid journey

Abstract

The polymorphic behavior of triacylglycerol (TAG) crystals formed during the manufacturing process of lipid-based food</p><p>products relates directly to their textural and melting properties. In this work, we analyzed the polymorphic crystallization</p><p>and transformation behavior of 1,2-dipalmitoyl-3-oleoyl-rac-glycerol (PPO), a widespread TAG in edible fats and oils, during</p><p>the application dynamic thermal treatments of cooling and heating. By implementing calorimetric, X-ray diffraction,</p><p>and microscopy techniques, we mapped the polymorphic occurrence and the polymorphic transformation pathways of PPO</p><p>as a function of the rate of thermal treatments. The results obtained were later compared to that reported for diverse TAGs</p><p>in previous studies. Despite the overall crystallization and transformation behavior of PPO following a similar trend to other</p><p>TAGs close in fatty acid composition, we can highlight the much lower influence of varying cooling and heating conditions</p><p>on the crystallization properties of this TAG. In more detail, crystalline forms of low stability were generally promoted</p><p>during crystallization, whereas transformations occurred always through the melt independently of the heating conditions.</p><p>One may expect this behavior to influence the industrial processing and final properties of food products based on edible</p><p>fats containing PPO.