4 research outputs found
Cristal·lització i polimorfisme de mescles de mantega de cacau i estearina de karité per al desenvolupament de nous sistemes lipídics
No full textTreballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2021, Tutores: Laura Bayés García, Mª Concepción López MartínezCocoa butter (CB) is a natural edible fat mainly composed of three main 1,3-disaturated-2-unsaturated triacylglycerols (TAGs): 1,3-dipalmitoyl-2-oleoyl-glycerol (POP), 1,3-distearoyl-2-oleoyl-glycerol (SOS), and rac-palmitoyl-stearoyl-2-oleoyl-glycerol (POS) and is responsible for the unique physicochemical properties of chocolate. In recent days, the increase in the demand for cocoa beans in the market has led to a rise in CB price, and for that reason the search for alternatives fats to CB is promoted. Some of these alternatives are Cocoa Butter Equivalents (CBEs), which usually are fat blends compatible with CB because of their similar physical and textural characteristics (melting, rheology, plasticity, etc.) compared to those of CB, and,
generally, are obtained by blending fats rich in POP and SOS. One of the fats used as a source of SOS is shea butter from which shea stearin (ShS) is obtained by fractionation.
This work focuses on studying blends based on cocoa butter and shea stearin as a way to develop new lipid systems with improved properties for specific applications, and also to find out how ShS influences some properties of CB. To achieve all of these, in this research, the polymorphic and crystallization behaviour, the solid fat index (SFI), and the crystal morphology of CB, ShS, and some CB:ShS blends were investigated through differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarized light microscopy (PLM) technique
Hydrolysis of Lactose: Conventional Techniques and Enzyme Immobilization Strategies on Polymeric Supports
No full textThis chapter explores lactose hydrolysis, emphasizing conventional techniques
and the noteworthy immobilization of β-galactosidase on polymeric matrices to
enhance the process. Lactose, present in milk and dairy, poses challenges for lactoseintolerant
individuals, requiring enzymatic hydrolysis for lactose-free product development.
The presence of other milk components, such as proteins and minerals, can
indirectly influence the efficiency of lactose hydrolysis by potentially interacting with
β-galactosidase enzyme or affecting its stability and activity, making it necessary to
control factors such as enzyme concentration, temperature, pH, and reaction time to
improve lactose hydrolysis rates. The chapter delves into established methodologies,
covering enzymatic kinetics, reaction conditions, and substrate concentrations. It
also describes the innovative approach of immobilizing β-galactosidase on polymeric
supports to enhance enzyme stability, reusability, and overall efficiency in lactose
hydrolysis. Discussions include the design of suitable polymeric matrices, providing
insights into mechanisms governing catalytic performance. This comprehensive
exploration contributes to understanding lactose hydrolysis, offering valuable insights
for developing efficient and sustainable enzymatic processes applicable to the food
and pharmaceutical industries.We gratefully acknowledge the financial support provided by all funders. This work was supported by the Regional Government of Castilla y León (Junta de Castilla y León) and by the Ministry of Science and Innovation MICIN and the European Union NextGenerationEU PRTR. Author Saul Vallejos received grant BG22/00086 funded by the Spanish Ministerio de Universidades. Author Jose Miguel García received grant PID2020-113264RB-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe,” The financial support provided by Fondo Europeo de Desarrollo Regional-European Regional Development Fund (FEDER, ERDF) and Regional Government of Castilla y León -Consejería de Educación, Junta de Castilla y León- (BU025P23) is gratefully acknowledged
Cobalt ferrite magnetic nanoparticles as stirring actuators to improve UV–Vis spectroelectrochemical measurements in normal reflection mode.
No full textSpectroelectrochemical (SEC) measurements using UV–Vis radiation in normal reflection mode (or normal configuration)are less sensitive than parallel approaches, since the volume of sample monitored has a much lower proportion of the diffusionlayer created by the electrochemical processes, i.e., the region where relevant optical changes take place. In contrast,the normal configuration is more robust and reproducible and, as of today, is the only commercially available. This workpresents a strategy to enhance normal reflection SEC measurements of Fe(III)/(II)-orthophenanthroline system using ascreen-printed carbon electrode (SPCE), improving competitiveness with parallel designs. This method required the designof a new measuring cell based on the geometry of the commercial one, but replacing the eight magnets by a non-magneticclosing system. The developed approach involves adding cobalt ferrite magnetic nanoparticles (CoFe2O4 MNPs) to theanalyte solution and coupling the SEC cell to a conventional magnetic stirrer. The resulting nanostirring, driven by MNPsmovement, enhances mass transport toward the electrode. This accelerates diffusion layer renewal, leading to a noticeableincrease of both electrochemical and optical signals
Support STL files for a Spectroelectrochemical 3D designed cell for magnetic nanostirring
No full textSTL Files for the 3D Printing of a Customized Spectroelectrochemical Cell for Magnetic Nanostirring Applications on the SPELEC Instrument (Metrohm)
This dataset contains STL files for the 3D printing of a customized spectroelectrochemical (SEC) cell specifically designed to enable magnetic nanostirring during SEC measurements using the SPELEC instrument (Metrohm). The original design was created using FreeCAD software.
The printed cell used in experimental studies was fabricated in black polylactic acid (PLA) using an XYZPrinter da Vinci 1.0 Pro equipped with a 0.4 mm nozzle. The design includes two modular parts forming the main cell body, incorporating a 4-pillar structure to ensure proper sealing and minimize external light interference during measurements. This configuration allows for the use of magnetic nanostirring with sample volumes as low as 50 µL when placed on a standard magnetic stirrer platform.
The closure mechanism in this design provides an alternative to the standard commercial SEC cell, which uses a magnetic coupling closure system that is not compatible with magnetic nanostirring under equivalent experimental conditions.
The files are provided in STL format and can be directly used for additive manufacturing using common FDM 3D printers
