219 research outputs found
Functional Fat Blends of Specific Mixture Systems of Saturated-Oleic Mixed Acid Triacylglycerols: Impact of Molecular Compound Crystal Formation
Critically increasing high demands for trans-free and reduction of saturated fats have been asking lipid researchers to develop novel ideas of materials designs of hard stocks for various edible fats
Mixing phase behavior of trilaurin and monounsaturated triacylglycerols based on palmitic and oleic fatty acids
Differential scanning calorimetry and X-ray diffraction were used to examine the mixing phase behavior of LLL (trilaurinor 1,2,3-trilauroyl-glycerol) and POP (1,3-dipalmitoyl-2-oleoyl-glycerol), PPO (1,2-dipalmitoyl-3-oleoyl-rac-glycerol), orthe 50POP/50PPO blend able to form a molecular compound. This research aims to provide an insight into the molecularinteractions ruling the physical behavior of fat blends of lauric (i.e., coconut oil) and non-lauric lipids (cocoa butter, palmoil, etc.). The results showed eutectic behavior and no mutual solubility of triacylglycerols in stable LLL/POP and LLL/PPO mixtures. Applying high-rate cooling treatments had a positive effect on miscibility, but the high incompatibility ofthe components due to differences in length and degree of unsaturation of fatty acids was still evident in metastable polymorphs.In ternary LLL/(50POP/50PPO) mixtures, on the other hand, molecular compound β-2L crystals formed by POPand PPO showed to favor the solubility of LLL as compared to the binary systems. Accordingly, promoting the presence oftriacylglycerols forming molecular compound in specific fat blends may help reducing eutectic or incompatible interactionsamong triacylglycerol molecules in the solid state. These lead to phase separation and are a major cause of the restrictedapplicability of lauric oils in the confectionery and chocolate industries
An insight into the solid-state miscibility of triacylglycerol crystals
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
Deliciosos polimorfos
El polimorfismo, tan habitual y conocido por geólogos en minerales como la calcita-aragonito, el diamante-grafito y el grupo de la sílice, se extiende a muchos otros campos. Desde la cristalografía y la mineralogía, dando un gran salto en los materiales pero no en los fenómenos, el polimorfismo también tiene lugar en productos alimentarios. En particular, los triacilgliceroles, los cuales constituyen los componentes mayoritarios de grasas y aceites, tales como el chocolate, el aceite de oliva o el jamón ibérico, muestran un complejo comportamiento polimórfico (Larsson et al., 2006). La caracterización de sus formas cristalinas resulta crucial en aplicaciones de la industria alimentaria para satisfacer las necesidades del consumidor, optimizar procesos industriales o desarrollar nuevos productos. Sin embargo, el polimorfismo también podría ser utilizado como herramienta discriminatoria entre diferentes categorías de un mismo producto alimentario, así como para la detección de acciones fraudulentas (Bayés-García et al., 2016)
Chocolate: a useful model for teaching basic terms on Crystallography and Thermodynamics
By using a simple, attractive and sweet model, as chocolate is, many scientific concepts related to different disciplines, which are often understood as complex and dull by most students, may be introduced. In particular, the student may be able to develop crystallographic concepts and methodologies combined with some thermodynamic aspects, which have been historically known as complex and arduous disciplines. Hence, the student may enjoyably assimilate complicated concepts such as polymorphism, mixing behavior, crystal morphology, crystal size or thermodynamic stability, and may also be capable of understanding their application to daily life. These concepts may be applicable to any kind of material and can be more deeply developed depending on the level required
Solvent dependent formation of Cu (II) complexes based on isonicotinamide ligand
Five solvent-dependent Cu(II) compounds have been synthesized with [Cu(μ-OAc)(μ-Pip)(MeOH)]2 (OAc = acetate; Pip = 1,3-benzodioxolecarboxylate) and isonicotinamide (Isn) as an auxiliary ligand in different solvents. In all the compounds, Pip units are displaced resulting in dimeric [Cu(μ-OAc)(OAc)(Isn)2(solvent)]2 (solvent = MeOH (2a), dmf and H2O (3) or H2O and HPip (4a)), paddle-wheel [Cu(μ-OAc)2(Isn)]2·2dmso (5) or monomeric compounds [Cu(OAc)2(HOAc)(Isn)2]·HOAc (6). All of them have been characterized by analytical and ATR-FTIR techniques and their X-ray crystal structures solved. The OAc anions construct different arrays and exhibit different coordination modes depending on the solvent used. The supramolecular expansion is constantly determined by the amide-amide pattern and the role of the occluded solvent molecules. This tendency is confirmed by Hirshfeld Surface analysis. Finally, the thermal stability of compound 4a has been analyzed
Resonance-Based microwave technique for body implant sensing
There is an increasing need for safe and simple techniques for sensing devices and prostheses implanted inside the human body. Microwave wireless inspection may be an appropriate technique for it. The implanted device may have specific characteristics that allow to distinguish it from its environment. A new sensing technique based on the principle of differential resonance is proposed and its basic parameters are discussed. This technique allows to use the implant as a signal scattering device and to detect changes produced in the implant based on the corresponding change in its scattering signature. The technique is first tested with a canonic human phantom and then applied to a real in vivo clinical experiment to detect coronary stents implanted in swine animalsPeer ReviewedPostprint (published version
Polymorphic fingerprint as an approach to authenticate Iberian pig categories
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 < 0.05) from that of cebo de campo and cebo. The latter exhibited higher crystallization and melting temperatures than bellota and recebo samples, due to the occurrence of an additional β′-2L polymorphic form. By considering the differences in rearing systems of pigs belonging to the different categories, we concluded that the key factor which determined the polymorphism of Iberian pig lipid extracts was not the physical exercise practiced by the pig, but the inclusion of acorns in the feeding system. This work demonstrated that thermal and crystallographic techniques, like DSC and XRD, may be promoted to be used as fingerprinting tools for the authentication of high-value food products
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