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Polymorphic crystallization of cocoa butter (CB) in a bulk system was examined for the influence of adding talc particles at different concentrations (0.1%-5%). While the system was cooled from the melt and subsequently heated, changes in the heat flow and crystal structure of CB were analyzed using differential scanning calorimetry (DSC) and synchrotron radiation X-ray diffraction (SR-XRD). Synchrotron radiation microbeam X-ray diffraction (SR-µ-XRD) was employed to determine lamellar-plane directions of CB crystals occurring with talc addition. At any cooling rates (0.1-15 °C/min) applied, talc promoted CB crystallization to elevate the onset crystallization temperature logarithmically with the increasing concentration of talc; this effect became more prominent at higher cooling rates. Talc also acted as a polymorphic stabilizer, so that CB crystallized in more stable forms even when cooled at the highest rate of 15 °C/min. Moreover, a highly ordered lamellar-plane direction was extensively observed for CB crystals occurring with 0.1% talc addition, which was disturbed by 0.5% talc addition probably due to the spatial dispersion of densely populated talc particles in their randomized orientation. These heterogeneous nucleation effects indicate the potential of talc particles to be used for quality and productivity control of CB-based products.

Simetría es equivalencia, proporción, armonía e incluso belleza. La simetría está implícita en los cristales, y por lo tanto en los minerales, como una propiedad derivada de la periodicidad. Nos ayuda en la comprensión y descripción de la materia cristalina, tanto a escala macroscópica como microscópica. Pero simetría es un concepto interdisciplinar por excelencia que utilizamos en química, física, matemáticas, zoología, botánica, y también en la música, la pintura, la ornamentación, la arquitectura…A un nivel de divulgación científica desarrollaremos algunos conceptos fundamentales de la simetría y los aplicaremos en diferentes dominios de nuestro entorno cotidiano.

Arbequina monovarietal extra virgin olive oil (EVOO) was fractionated through a multi-step dry fractionation method. Three of the isolated fractions were selected and analyzed: one being liquid at 4 °C, and two being solid at 4 °C, and at 12 °C. Differential scanning calorimetry (DSC) combined with synchrotron radiation X-ray diffraction (SR-XRD) techniques were employed to monitor the polymorphic crystallization and transformation processes when samples were cooled from the melt to complete crystallization and reheated at a rate of 2 °C/min. Fatty acid profiles and α-tocopherol contents were also determined for EVOO and associated fractions. Each sample exhibited a different and unique crystallization and polymorphic behavior, and the number of crystallizing forms and complexity of transitions increased for solid fractions. In more detail, just two polymorphs (β'3- 2L and β'2-2L) were detected in the liquid fraction, whereas the fraction which remained in the solid state at 12 °C exhibited six different phases (α-2L; β'3-2L; β'2-2L; β'1-2L; β'2-3L; β'1-3L). These dissimilarities were strongly correlated with meaningful variations in the fatty acid moieties forming TAG structures and caused large deviations in the crystallization and melting temperatures. As an example, melting temperatures of the liquid and the solid fraction at 12 °C were about -3 °C and 17 °C, respectively. It may be worth exploring the potential of EVOO fractions to be used for improving properties of food stuff, among others. The liquid fraction may be of interest due to its high nutritional value owing to elevated contents in monounsaturated fats and antioxidants, whereas the solid fraction at 12 °C may become a good choice to be used as a high-oleic soft fat.

Differential scanning calorimetry and X-ray diffraction were used to investigate the mixing behavior of triacylglycerol (TAG) mixtures of PPP/PPO (tripalmitoyl glycerol/1,2-dipalmitoyl-3-oleoyl-rac-glycerol) and PPP/MCPOP/PPO (where MCPOP/PPO is the equimolecular blend of 1,3-dipalmitoyl-2-oleoyl-glycerol and PPO forming a molecular compound) under metastable and stable conditions. During cooling and reheating treatments at moderate rates, the eutectic properties of the two systems examined were mainly governed by the crystallization, transformation, and melting behavior of structurally similar β′ forms. In addition, steric and kinetic effects determined the formation of solid solutions with up to 10% and 20% of mixed-acid components in PPP/PPO and PPP/MCPOP/PPO mixtures, respectively. These values increased to 30% and 35% when thermodynamically stable β crystalline phases were obtained. In PPP/MCPOP/PPO mixtures, the diffraction data suggested that POP and PPO acted as a single component by dissolving in similar amounts in the solid solution phases and forming molecular compound crystals in eutectic compositions. This fundamental research shows the important role of specific combinations of mixed-acid TAGs and their interaction with high-melting components on the solidification behavior of edible lipids.

The binary phase behavior of triacylglycerol (TAG) mixtures constituted by PPP (tripalmitin) and either POP (1,3-dipalmitoyl-2-oleoyl-glycerol), OPO (1,3-dioleoyl-2-palmitoyl-glycerol), or MCPOP/OPO (molecular compound formed by POP/OPO at a 1:1 concentration ratio) was determined by differential scanning calorimetry (DSC), synchrotron (SR-) and laboratory-scale X-ray diffraction (XRD). Steric hindrance due to saturated-unsaturated acyl chain interactions and differences in the thermal stability of TAGs seemed to dictate the independent polymorphic crystallization and transformation observed under kinetic conditions, as well as the very asymmetric eutectic-type phase diagrams obtained from the study of thermodynamically stabilized PPP/POP, PPP/OPO, and PPP/MCPOP/OPO mixtures. Moreover, the solid integration determined for MCPOP/OPO in the βPPP crystalline phase (20-25%), halfway between that of OPO (

High-commercial-value products are often susceptible to food fraud. Among them, Iberian dry-cured ham is highly appreciated due to its particular and sensory, but also nutritional, properties. There are four different Iberian ham categories (namely bellota, recebo, cebo de campo and cebo), which directly depend on the rearing system of the pig during the last stage of the fattening phase. However, there is still a lack of a normalized and robust method capable of authenticating the different product categories and, therefore, preventing mislabeling. In the present work, we characterized the polymorphic behavior of raw (before curing) lipid extracts belonging to the four categories of Iberian pig. A total of 80 different samples were analyzed by DSC, and synchrotron radiation XRD experiments were carried out for selected ones. The results obtained showed that bellota and recebo categories exhibited essentially the same crystallization and polymorphic behavior and this was significantly different (p

The crystallization properties of triacylglycerols (TAGs) strongly determine the functional properties of natural lipids. The polymorphic and mixing phase behavior of TAG molecules have long been, and still are, a hot topic of research with special relevance for the cosmetic, pharmaceutical, and food industry. To avoid the difficulties arising from the study of whole real fats, studies at the molecular level on mixtures of a limited number of TAGs has become an indispensable tool to identify the underlying causes of the physical properties in lipid systems. In particular, phase diagrams of binary mixtures of TAGs exhibiting a different degree of heterogeneity (monoacid or mixed fatty acids; molecular symmetry; the presence of cis or trans double bonds) have resulted in a significant breakthrough in our knowledge about structure–interaction–function relationships. The present work aims to provide an overview of the main reports regarding binary and ternary TAG systems, from the early studies to the most recent developments.

The aim of this work is to study the influence of different substituents in two closely related ligands, 3,5-dihydroxybenzoate (3,5-(HO)2Bz) and 3,5-dimethoxybenzoate (3,5-(MeO)2Bz), in the structure of zinc complexes. The compound [Zn(3,5-(MeO)2Bz)2(CH3OH)]2 (2) has been synthesized, characterized and its crystal structure elucidated, showing a paddle wheel type dinuclear molecule, with four bridging carboxylate ligands in a syn-syn coordination mode and methanol molecules in the apical positions. This discrete structural array is different than the polymeric structure observed in {[Zn(µ-3,5-(HO)2Bz)(µ-OH2)(H2O)2]·3,5-(HO)2Bz·4H2O}n, previously reported in our group. These two zinc complexes were used as precursor for the synthesis of coordination polymers (CPs) with the 4,4′-bipyridine (4,4′-bpy) linker. The solvent used in their synthesis influences the chemical composition of this CPs. Thus, {[Zn(3,5-(HO)2Bz)2(µ-4,4′-bpy)]·2DMSO}n (3) was achieved in dimethylsulfoxide (DMSO) while {[Zn(3,5-(HO)2Bz)2(µ-4,4′-bpy)]·4,4′-bpy·1/2CH3OH}n (4) was formed in methanol (MeOH) as solvent. The reaction of 2 with 4,4′-bpy yielded [Zn2(μ-3,5-(MeO)2Bz)4(µ-4,4′-bpy)]n (5) in methanol, while after recrystallization in boiling water, complex {[Zn(3,5-(MeO)2Bz)2(µ-4,4′-bpy)]·H2O}n (6) was isolated in low yield. This compound 6 can also be synthesized by a mechanochemical approach, using water in a liquid assisted grinding. The crystal structures of complexes 3, 4 and 6 were elucidated, all three showing zigzag polymeric arrays. Both polymers containing 3,5-(MeO)2Bz (5 and 6), showed solid state luminescence.

The present study aims at observing the crystallization and polymorphic behavior of cocoa butter (CB) in fresh cacao beans with DSC and X-ray diffraction techniques. Underlying idea of this study was to relate the necessary conditions of germination of cacao beans to the crystallization of CB, which are present in oil-in-water emulsion droplets (lipid bodies) with diameters of 1-2 μm. Different cooling and heating conditions, with rates of 15, 2, 0.5, and 0.1 °C/min, were applied to fresh cacao beans and compared to bulk CB. The results showed that the crystallization temperatures (Tc) of CB in fresh cacao beans were lower than those of bulk CB at all the experimental conditions. In addition, polymorphic behavior of the occurrence of metastable and stable forms of CB was also different between the fresh cacao beans and the bulk state. The thermal behavior of fresh and dried cacao beans that have different geographical origins was also analyzed. This study indicates that the germination conditions of cacao beans are extended to low-temperature environmental areas by reducing the Tc value of CB in fresh beans than of the bulk oil. The results were consistent with the germination experiments of fresh cacao beans at different temperatures.

We examined the influence of dynamic thermal treatment (variation of cooling/heating rates) on the polymorphic crystallization and transformation pathways of 1-palmitoyl-2,3-dioleoyl glycerol (POO), 1-stearoyl-2,3-dioleoyl glycerol (SOO), and 1-palmitoyl-2-oleoyl-3-linoleoyl glycerol (POL), which are major saturated-unsaturated-unsaturated (SUU) triacylglycerols (TAGs) of vegetable oils and animal fats (e.g., palm oil, olive oil, and Iberian ham fat). Using mainly a combination of differential scanning calorimetry (DSC) and synchrotron radiation X-ray diffraction (SR-XRD), we analyzed the polymorphic behavior of TAGs when high (15 °C min− 1), intermediate (2 °C min− 1), and low (0.5 °C min− 1) cooling and heating rates were applied. Multiple polymorphic forms were detected in POO, SOO, and POL (sub-α, α, β'2, and β'1). Transient disordered phases, defined as kinetic liquid crystal (KLC) phases, were determined in POO and SOO for the first time. The results demonstrated that more stable forms were directly obtained from the melt by decreasing the cooling rates, whereas less stable forms predominated at high cooling rates, as confirmed in our previous work. Regarding heating rate variation, we confirmed that the nature of the polymorphic transformations observed (solid-state, transformation through KLC phase, or melt-mediation) depended largely on the heating rate. These results were discussed considering the activation energies involved in each process and compared with previous studies on TAGs with different saturated-unsaturated structures (1,3-dioleoyl-2-palmitoylglycerol, 1,3-dipalmitoyl-2-oleoyl-glycerol, trioleoyl glycerol, and 1,2-dioleoyl-3-linoleoyl glycerol).

Foods with high added value, such as Iberian dry-cured products, are susceptible to fraud. Many attempts have been made to differentiate the commercial/quality categories of Iberian dry-cured hams by analytical determinations. However, as discrimination by such means is not fully reliable, legislation to prevent fraudulent practice is based on administrative controls and certification. Here, new analytical approaches based on ultrahigh resolution mass spectrometry (UHRMS) and crystallographic techniques applied to the lipid fraction, in combination with chemometrics, are studied. The results of the triacylglycerol profile determined by UHRMS and the fingerprint provided by the thermograms obtained by differential scanning calorimetry offer the promise of analytic discrimination of Iberian dry-cured ham categories. In addition, these determinations, in combination with chemometrics, may prove extremely useful to authenticate many foods containing high to moderate amounts of lipids.

The complexes [Cu(PhOBz)2(dPy)]2 (PhOBz = 4-phenoxybenzoate; dPy = pyridine (1), 3-phenylpyridine (2), 4-benzylpyridine (3) and 4-phenylpyridine (4) and the complex [Cu(PhOBz)2(4-Phpy)2(H2O)] (5) were prepared and fully characterized. X-ray crystal structures of the five complexes have been determined. Complexes 1–4 consist of binuclear units where both Cu(II) are linked by four syn–syn carboxylate bridges, showing a paddle-wheel unit. The compound 5 is mononuclear and the metal center is coordinated to two PhOBz in monodentate form, two 4-Phpy ligands and one H2O molecule with slightly distorted square pyramidal geometry. Finally, the magnetic properties of compounds 3 and 5 have also been studied, confirming the different strength interactions between Cu(II) cations.

Five new coordination compounds [Zn(μ‑3,5‑DHB)2(H2O)2]n (1a), [Zn(μ‑3,5‑DHB)(μ‑OH2)(H2O)2]n·(3,5‑DHB)n·(4H2O)n (1b), [Zn(3,5‑DHB)2(Isna)2]·2H2O (2), [Zn(3,5‑DHB)2(4‑Acpy)2]·3H2O (3) and [Zn(3,5‑DHB)2(3‑Mepz)2]·H2O (4) (3,5‑HDHB = 3,5‑dihydroxybenzoic, Isna = isonicotinamide, 4‑Acpy = 4‑acetylpyridine and 3‑Mepz = 3‑methylpyrazole) were synthesized in water or water-methanol as solvents. All these compounds have been characterized by elemental analysis, FTIR-ATR and 1H NMR spectroscopies and Powder X-ray diffraction (PXRD). For compounds 1b–4, X-ray crystal structures have been determined. In these compounds, 3,5‑DHB ligand displays different coordination modes. Complex 1b is a coordination polymer, while the addition of the pyridine/pyrazole ligands in the reaction provokes the formation of monomeric compounds (2–4). Moreover, the crystal packing indicates that these complexes expand into 2D/3D network structures mainly by intermolecular hydrogen bond interactions. Finally, the photoluminescent properties of these complexes in solid state have also been investigated. The strong emission observed for 1b indicates that it may be a good candidate for photoluminescent devices.

The polymorphic crystallization and transformation behavior of extra virgin olive oil (EVOO) was examined by using differential scanning calorimetry (DSC) and X-ray diffraction with both laboratory-scale (XRD) and synchrotron radiation source (SR-XRD). The complex behavior observed was studied by previously analyzing mixtures composed by its main 2 to 6 triacylglycerol (TAG) components. Thus, component TAGs were successively added to simulate EVOO composition, until reaching a 6 TAGs mixture, composed by trioleoyl glycerol (OOO), 1-palmitoyl-2,3-dioleoyl glycerol (POO), 1,2-dioleoyl-3-linoleoyl glycerol (OOL), 1-palmitoyl-2-oleoyl-3-linoleoyl glycerol (POL), 1,2-dipalmitoyl-3-oleoyl glycerol (PPO) and 1-stearoyl-2,3-dioleoyl glycerol (SOO). Molten samples were cooled from 25 °C to − 80 °C at a controlled rate of 2 °C/min and subsequently heated at the same rate. The polymorphic behavior observed in multicomponent TAG mixtures was interpreted by considering three main groups of TAGs with different molecular structures: triunsaturated OOO and OOL, saturated-unsaturated-unsaturated POO, POL and SOO, and saturated-saturated-unsaturated PPO. As confirmed by our previous work, TAGs belonging to the same structural group displayed a highly similar polymorphic behavior. EVOO exhibited two different β'-2 L polymorphic forms (β'2-2 L and β'1-2 L), which transformed into β'-3 L when heated. Equivalent polymorphic pathways were detected when the same experimental conditions were applied to the 6 TAG components mixture. Hence, minor components may not exert a strong influence in this case.

The ongoing academization of gastronomic studies indicates the necessity for a commonly accepted classification system for cooks that does not contradict scientific approaches. This work discusses the fundamentals used by chefs and scientists to classify unelaborated food products; proposes taxonomic gastronomy as a new interdisciplinary framework that studies the taxonomy surrounding gastronomy; and presents a categorization of unelaborated food products that follows commonly accepted culinary criteria yet avoids contradiction by scientific knowledge. As little literature focuses on these issues, and similar experiences are scarce, it is concluded that further cross-disciplinary endeavors such as this will continue to be greatly fruitful., This work was carried out in the framework of the agreement between the Universitat de Barcelona and elBulliFoundation signed on 23 October 2012 and was subsidized by the Catalan government (grant number 2009SGR0403, 2014SGR1241, 2014SGR7, 2014SGR514, 2014SGR1315, 2014SGR1208, 2014SGR1480 and 2014SGR623).

Many physical properties (e.g., hardness, texture, rheology, and spreadability) of lipid‐based products largely depend on the extent of crystallization and transformation of lipids, and their network formation. Therefore, many studies have focused on controlling the crystallization of lipids in order to determine the functionality of lipid crystals. Both internal and external factors greatly affect the processes of lipid crystallization. The most important internal factors are polymorphism, which depends on variation in fatty acid moieties, and the composition or blending of different lipid materials. Important external factors are thermal treatment, additives, application of shear, sonication, and pressure. This paper briefly reviews recent advances in research on these external factors. We discuss the results by considering the relationships between external factors and thermodynamics, as well as kinetic properties of the crystallization and transformation of polymorphic forms of lipid crystals.

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

We systematically examined the phase behavior of binary mixtures of mixed-acid triacylglycerols (TAGs) containing palmitic and oleic acid moieties 1,3-dioleoyl-2-palmitoyl-glycerol (OPO), 1,2-dipalmitoyl-3-oleoyl-rac-glycerol (PPO), and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (OOP), which are widely present in natural fats and are employed in the food, pharmaceutical, and cosmetic industries. Differential scanning calorimetry and X-ray diffraction methods were applied to observe the mixing behavior of PPO/OPO, OOP/OPO, and PPO/OOP under metastable and stable conditions. The results led to three conclusions: (1) Eutectic behavior was observed in PPO/OPO. (2) Molecular compound (MC) crystals were formed in the mixtures of OOP/OPO and PPO/OOP. (3) However, the MC crystals occurred only under metastable conditions and tended to separate into component TAGs to form eutectic mixture systems after 17 months of incubation. These results were contrary to those of previous studies on 1,3-dipalmitoyl-2-oleoyl glycerol (POP)/OPO and POP/PPO in which the MC crystals were thermodynamically stable. We determined that specific molecular interactions may cause this different phase behavior (stability of POP/OPO and POP/PPO MC crystals and metastability of OOP/OPO and PPO/OOP MC crystals). All results confirm the significant effects of molecular structures of glycerol groups, interactions of fatty acid chains, and polymorphism of the component TAGs on the mixing behavior of mixed-acid TAGs.

The extent of crystallization and transformation of lipids, and their network formation, play decisive roles in determining physical properties (e.g., hardness, texture, rheology, and spreadability) of lipid-based food products. In these products, the lipid materials are present in rather complicated physical states such as mixtures of solid and liquid lipids or emulsified with water phases. In addition, various external influences are applied during actual production in a factory. Therefore, exploration of lipid crystallization under multiple external influences is necessary to improve the functionality of lipid-based food products.

This study examined the influence of different thermal treatments on the crystallization and transformation of trioleoyl glycerol (OOO) and 1,2-dioleoyl-3-rac-linoleoyl glycerol (OOL). Two triacylglycerol (TAG) samples were cooled at 0.5-15 °C·min(-1) and heated at 2 and 15 °C·min(-1). The polymorphic characteristics of the two TAGs were analyzed in situ using differential scanning calorimetry, Raman spectroscopy, and synchrotron radiation X-ray diffraction. Multiple polymorphic forms were identified in OOO (α, β'2, β'1, β2, and β1) and OOL (α, β'2, and β'1). Larger quantities of more stable forms (e.g., β2 and β1 of OOO and β'1 of OOL) were obtained when the samples were slowly cooled and heated. In contrast, less stable polymorphs were obtained with increased cooling and heating rates. Polymorphic transformations occurred in either solid-state or melt-mediation and were influenced by heating rates. The results were analyzed by considering the activation energies for crystallization and transformation of stable and less stable polymorphic forms in comparison with previous studies on 1,3-dipalmitoyl-2-oleoyl-glycerol and 1, 3-dioleoyl-2-palmitoyl-glycerol.

We examined the influence of kinetics on the polymorphic behavior of 1,3-dioleoyl-2-palmitoyl glycerol (OPO), a triacylglycerol (TAG) present in natural oils such as olive oil and human breast milk. Pure OPO was heated at 15 °C min−1 in all cases. The polymorphic crystallization of OPO was studied at different cooling rates (15, 2, 1, and 0.5 °C min−1), and the dynamic polymorphic transformations were characterized on heating by simultaneously using Differential Scanning Calorimetry (DSC) and Synchrotron Radiation X-Ray Diffraction (SR-XRD) with small-angle X-ray diffraction (SAXD) and wide-angle X-ray diffraction (WAXD). Thermo-Optical Microscopy (TOM) was also used in order to observe the polymorphic transitions. Polymorphic forms of OPO were identified and characterized. As the cooling rate decreased, more stable forms crystallized, not following the Ostwald step rule, although in most cases concurrent crystallization occurred and the whole process was highly complex.

In this study, phase change materials (Rubitherm® RT 27) microcapsules were successfully obtained by two different methods. The main difference between them remains on the shell composition, as they are composed of different coacervates (Sterilized Gelatine/Arabic Gum for the SG/AG method and Agar-Agar/Arabic Gum for the AA/AG method). Microcapsules were thermally characterized by thermo-optical microscopy and differential scanning calorimetry. Using scanning electron microscopy, their spherical morphology (sphericity factor of 0.94–0.95) and their particle size distribution were determined, obtaining an average diameter of 12 μm for the SG/AG method and lower values for the AA/AG method, where nanocapsules were also observed (average diameter of 4.3 μm for the microcapsules and 104 nm for the nanocapsules). The thermal stability determination was carried out by Thermogravimetric analyses (TG) and the results show a high decomposition temperature, although the process takes places in four steps for the two mentioned methods. Moreover, the microcapsules obtained by the AA/AG method decompose in a more gradual way, as in the TG results a double step, instead of one, is appreciable. On the whole, the prepared microencapsulated PCM are totally capable of developing their role in thermal energy storage.

The kinetic properties of crystallization and structural transformation are important, particularly for the application of polymorphic crystal systems in pharmaceutical, biomedical, food technology, and other applications. Triacylglycerols (TAGs) are the main components of alimentary fats and oils. Fat structures and compositions determine their physical properties (e.g., rheology, morphology, and texture), where polymorphism exerts a strong influence. There are different polymorphic forms of TAGs: the most general ones (in increasing stability) are: α form, which crystallizes in the hexagonal system, β' form (orthorhombic system) and β form (triclinic system). In this study, several techniques, like Synchrotron Radiation X-Ray Diffraction, Thermal Analysis and Thermo-optical Microscopy, were used in order to characterize the polymorphism under the kinetic point of view of some TAGs present in edible oils and fats. Therefore, the role of some kinetic parameters (e.g. cooling and heating rates) is highlighted.

We observed microstructures of spherulites made of two triacylglycerols (TAGs) (POP (1,3-dipalmitoyl-2-oleoyl-sn-glycerol) and OPO (1,3-dioleoyl-2-palmitoyl-sn-glycerol)), which exhibit the mixing behavior of a molecular compound (MC) formation at a ratio of POP : OPO = 50 : 50, using synchrotron radiation microbeam (beam area of 5 × 5 μm2) X-ray diffraction (SR-μ-XRD). The spherulites were grown from neat liquid, and from solution containing 50% n-dodecane and 50% POP + OPO. SR-μ-XRD analysis revealed heterogeneous distributions of MCPOP:OPO and component TAGs in every spherulite; TAG compositions in the inner and outer areas differed when the relative ratios of POP and OPO were changed. In the 75POP : 25OPO spherulites, MCPOP:OPO always occupied the inner areas and POP dominated the outer areas as a result of different rates of crystallization of MCPOP:OPO and POP in the spherulite. In contrast, in the 25POP : 75OPO spherulites, the entire area was homogeneously occupied either with almost all OPO or with coexisting MCPOP:OPO and OPO. The microstructures of the spherulites grown from n-dodecane solutions demonstrated basically the same characteristics as those grown from the neat liquid both for 75POP : 25OPO and 25POP : 75OPO. SR-μ-XRD also clarified that the lamellar planes of the crystals are directed parallel to the radial direction from the central to the outer regions of the spherulites.