Extracción asistida por ultrasonido de compuestos bioactivos con actividad antioxidante de grano de cacao (theobroma cacao l.)

Tesis (Doctorado en Tecnología Avanzada). Ciudad de México, Instituto Politécnico Nacional, PTA, CICATA, Unidad Legaria. 2016. 1 archivo PDF, (118 pàginas). tesis.ipn.m

Design cocoa processing towards healthy cocoa products : The role of phenolics and melanoidins

Roasting and fermentation are key steps in cocoa processing that can be modulated to optimize the presence of health-promoting compounds in the final product. Roasting promote melanoidins formation and polyphenols depolymerization. Results of Forastero and Criollo cocoa beans were processed in different conditions showed that higher fat content and high phenolic content could promote melanoidins formation. Forastero variety had the highest melanoidins and phenols concentration under severe roasting conditions. More severe thermal treatment decreased the concentration of total phenolic compounds and proanthocyanidins in both varieties and also influenced the flavan-3-ols profile. The antioxidant activity determined using DPPH Quencher assay was the highest in Forastero fractions above 20 kDa obtained under severe roasting condition; thus supporting the idea that melanoidins play a major role in roasted cocoa antioxidant activity. It can be concluded that a proper design of roasting process and the adequate selection of cocoa variety can optimize the cocoa health potential; especially melanoidins and phenolic compounds

Development and characterization of gelatin nanoparticles loaded with a cocoa-derived polyphenolic extract

Introduction. Polyphenols have received significant attention in recent years due to their antioxidant capacity and their significant role in disease prevention. Cocoa is one of the major naturally occurring sources of antioxidants, particularly of polyphenolic compounds. Materials and methods. Gelatin nanoparticles loaded with a cocoa-derived polyphenolic extract were synthesized by nanoprecipitation. The nanoparticle synthesis was performed using a central composite experimental design that allowed for the assessment of how gelatin concentration and surfactant concentration (Tween 80) affected the hydrodynamic diameter and polydispersity of the particles. The nanoparticles were characterized using dynamic light scattering (DLS), assessments of zeta potential, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Results. The analyses demonstrated that the nanoparticles examined exhibited hydrodynamic diameters of (100 to 400) nm, polydispersity indices of less than 0.2 and average zeta potential values of 29–33 mV. SEM images revealed that most nanoparticles were spherical and uniform in morphology, with average sizes less than 250 nm. In vitro experiments in which the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method was used to assess the prevalence of free radical-scavenging ability among these nanoparticles indicated that the loading efficiency for the nanoparticles was approximately 77.56%. Conclusion. Nanoparticles loaded with polyphenolic extract were obtained with average sizes ranging from (120 to 250) nm and largely spheroidal morphologies. Polymer and surfactant concentrations significantly influenced the hydrodynamic diameters and polydispersity indices of the particles. The incorporation of the polyphenolic extract into the polymer matrix enabled the preservation of the antiradical activity of the bioactive compound

Optimización del proceso de extracción asistida por ultrasonido de compuestos fenólicos de Justicia spicigera Schltdl. mediante la metodología de superficie de respuesta

The interest in the study of polyphenols has grown considerably in recent years due to its high capacity to scavenge free radicals associated with various diseases. For this reason, the aim of this work was to obtain and characterize phenolic compounds from Justicia spicigera Schltdl by ultrasound-assisted extraction. The extracts were characterized in terms of the total phenolic content (Folin-Ciocalteu method), antioxidant activity (ferric-reducing/antioxidant power) and free radical scavenging activity (2,2-diphenyl-1-picrylhydrazyl free radical method). The response surface methodology (RSM) was used to evaluate the effect of the solvent (water/ethanol) and the extraction time, on the total phenolic content and antioxidant properties. The analysis of variance (ANOVA) indicated that the concentration of water in the solvent mixture significantly affected the yield of the compounds, as well as the antioxidant and antiradical activities. According to the RSM, the optimal extraction conditions are 25% water in the solvent mixture and a sonication time of 16 min.El interés en el estudio de los polifenoles ha crecido de manera considerable en los últimos años debido a su alta capacidad para atrapar radicales libres asociados con diversas enfermedades. Por este motivo, el objetivo del presente trabajo fue obtener y caracterizar los compuestos fenólicos de Justicia spicigera Schltdl. mediante extracción asistida por ultrasonido. A los extractos, se les determinó el contenido fenólico total (método de Folin-Ciocalteu), actividad antioxidante (potencial antioxidante/reductor del hierro) y actividad secuestradora de radicales libres (método del radical libre 2,2-difenil-2-picrilhidrazil). La metodología de superficie de respuesta (MSR) se empleó para evaluar el efecto del disolvente (agua/etanol) y el tiempo de extracción, en el contenido de fenoles totales y las propiedades antioxidantes. El análisis de varianza (ANOVA) indicó que la concentración de agua en la mezcla del disolvente afectó de manera importante el rendimiento de los compuestos, así como la actividad antioxidante y antiradical. De acuerdo con la MSR, las condiciones óptimas para la extracción son 25% de agua en la mezcla del disolvente y un tiempo de sonicación de 16 minutos