Papers by Veronica Calado
Fermentation, Aug 23, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Brazilian Journal of Botany
Green Chemistry
Lignin is a tricky and complex structure. The growing interest in its use requires a unanimous ap... more Lignin is a tricky and complex structure. The growing interest in its use requires a unanimous approach to its nature; so, misconceptions that have already been overcome and those perpetuated by those who are not familiar with its complexity do not spread.
Biomass Conversion and Biorefinery
Macromolecules, 2021
To blend and process different high molar mass polymers into multiphase materials, predicting/con... more To blend and process different high molar mass polymers into multiphase materials, predicting/controlling their morphology and rheological behavior is paramount. Herein, a segmental repulsive poten...
Powder Technology, 2021
Abstract To mitigate the fluid invasion and the loss of circulation, drilling fluids are designed... more Abstract To mitigate the fluid invasion and the loss of circulation, drilling fluids are designed to provide a thin mudcake with low permeability. Among the many methods of determining the mudcake properties, the absence of proper procedures related to the estimation of mudcake parameters that also consider the experimental uncertainties is noticed. Besides, the non-Newtonian rheological behavior in filtration and its consideration in resistive force modeling is still lacking in the literature. This paper proposes a new methodology of parameter estimation using the particle swarm optimization technique with a modification of the classic model approaches considering the non-Newtonian fluid filtration theory, including the fluid phase rheological behavior. Static filtrations were performed in an HTHP filtration cell with non-Newtonian suspensions with concentrations like those used in actual drilling processes. The internal structure of the mudcakes was studied by SEM images. A reparameterization of the static filtration model was proposed for the simultaneous estimation of precise and uncorrelated parameters: filter resistance, permeability, and compressibility of the mudcakes, considering two different methodologies, Method I – classic and not advisable - and Method II – rigorous statistical process and pressure-dependent filtration properties. As shown in this research, the confidence intervals for all parameters obtained by Method II were narrow with significative statistical meaning, at a confidence level of 95%, and close to those obtained by other authors. Also, the reparameterization procedure removed the parametric correlation between the mudcake permeability and compressibility, resulting in parameters with null correlation. The numerical solution does not lead to a high computational cost and could be installed in an onboard control device to predict online filtration loss, providing valuable pieces of information in oil drilling processes.
This study aimed at investigating human fluids as bioavailability and excretion markers of chloro... more This study aimed at investigating human fluids as bioavailability and excretion markers of chlorogenic acids from coffee. Three caffeoylquinic acids and other non-esterified cinnamic acid derivatives were identified in human digestive fluids and plasma. In addition, three dicaffeoylquinic acids were identified in plasma. Our results show, for the first time, that chlorogenic acids from coffee are absorbed in humans, circulate in their blood stream and are partially excreted via saliva and gastro-intestinal fluids.
Advanced Powder Technology, 2021
Abstract To more closely bridge the technological advent of shear thickening fluids with material... more Abstract To more closely bridge the technological advent of shear thickening fluids with material applications, a well-defined sample preparation protocol is needed. In this work, preparation conditions have been studied for suspensions of precipitated calcium carbonate (PCC) particles by means of a 2 k Factorial Experimental Design (DOE), with three center points, and as a function of PCC particle shape. Shear thickening maximum viscosity was the response variable and the corresponding analyzed factors were: particle concentration, stirring time, stirring speed and sonication time. Samples with rosette PCC particles exhibited a stronger shear thickening behavior in view of stronger frictional interactions and they also shear thicken at lower shear rates compared to samples with acicular PCC particles. In the case of acicular PCC particles, the shear thickening fluid that provided the highest maximum viscosity η m was obtained with higher particle concentration, lower stirring speed and shorter sonication time, as acicular PCC particles align more easily in the flow direction. In the case of rosette PCC particles, η m was achieved with higher particle concentration, longer stirring time and shorter sonication time. Finding optimal sample preparation conditions and particle shapes that take the most advantage of shear thickening behavior is very important for final applications.
LWT, 2020
Beer is a drink appreciated by different cultures for its diversity and social interaction. The m... more Beer is a drink appreciated by different cultures for its diversity and social interaction. The microencapsulation can be used to concentrate and stabilize phenolic compounds; creating a product with possible functional claims and health properties. The present study developed a craft beer powder product using an experimental design to evaluate the influence of temperature on spray-drying, and maltodextrin proportions, as an encapsulating agent, and functional quality. The craft beer powder was also analyzed for stability, nutritional composition, and sensory aspects. Solubility assays revealed an average value of 95, the water activity was 0.28, and the total phenolic compounds of gallic acid equivalents was 97 mg g − 1 of dried weight. The characterization of powdered pure beer microparticles and maltodextrin associated microparticles showed satisfactory results for wettability (77 s), hygroscopicity (14%) and dispersibility (− 0.33 Δ Abs x 10) 3. In the stability study, no significant difference was observed in the reduction of phenolic compounds and antioxidant activity; both showed 100% retention in beer microparticles with and without maltodextrin over 180 days. The sensory analysis showed good acceptance. The powdered beer product presented antioxidant characteristics and the flavor was preserved with the elimination of alcohol, suggesting it could be an innovative product with possible health functions.
Journal of Non-Newtonian Fluid Mechanics, 2020
ABSTRACT Starch is synthesized in intracellular structures called amyloplasts, whose wraps delimi... more ABSTRACT Starch is synthesized in intracellular structures called amyloplasts, whose wraps delimiting the organelle are referred to as plastid membranes. Such envelopes are generally removed in the industrial processing of cereal starches, but not of cassava starch (CS), which is submitted to a different process. The occurrence of different rheological behaviors before a shear thickening (ST) event for granular starch suspensions is well known, but not yet thoroughly explained. The objective of this work was to study physical changes on commercial CS suspensions that could intensify their shear thickening properties when glycerol is used as a solvent. The results show that the removal of plastid envelopes from starch granules significantly reduces its deformable character in glycerol suspensions. It intensifies the delayed ST behavior and maintains the flow stability during an eventual discontinuous ST transition, provided that suspensions are conditioned at an adequate relative humidity (close to 43%). Experimental data also have suggested an explanation for why a Newtonian or a shear-thinning behavior precedes shear thickening in starch suspensions.
Materials Research Express, 2018
Carbohydrate Polymers, 2016
The influence of encapsulating carbohydrates (EC) with varying properties on the technological an... more The influence of encapsulating carbohydrates (EC) with varying properties on the technological and functional properties of jussara pulp microparticles produced by spray drying were evaluated using experimental design. Microparticles produced with sodium octenyl succinate (OSA) starch at 0.5 core to EC ratio and with mixtures of inulin and maltodextrin at 1.0 and 2.0 core to EC ratio showed darker color, and higher anthocyanins contents and antioxidant activity. Seven microparticles showing high water solubility and desirable surface morphology. Hygroscopicity (10.7% and 11.5%) and wettability (41s and 43s) were improved when OSA starch and mixtures of inulin and maltodextrin were used. The anthocyanins contents and color of the microparticles did not change when exposed to light at 50°C for 38days. Finally, microparticles produced at 1.0 core to EC ratio with 2/3 OSA starch, 1/6 inulin and 1/6 maltodextrin were selected. These microparticles may be applied as colorant in numerous foods, whilst adding prebiotic fiber and anthocyanins.
Polymer Composites, 2002
Composite materials are manufactured by different processes. In all, the process variables have t... more Composite materials are manufactured by different processes. In all, the process variables have to be analyzed in order to obtain a part with uniform mechanical properties. In the pultrusion process, two variables are the most important: the pulling speed of resin‐impregnated fibers and the temperature profile (boundary condition) imposed on the mold wall. Mathematical modeling of this process results in partial differential equations that are solved here by a detailed procedure based on the Galerkin weighted residual finite element method. The combination of the Picard and Newton‐Raphson methods with an analytical Jacobian calculation proves to be robust, and a mesh adaptation procedure is presented in order to avoid integration errors during the process optimization. The two earlier‐mentioned variables are optimized by the Simulated Annealing method with some constraints, such as a minimum degree of cure at the end of the process, and the resin degradation (the part temperature ca...
Journal of Food and Nutrition Research
Food and Bioprocess Technology, 2020
Gelatin-based nanocomposite films were prepared by casting and characterized as a sensitive hybri... more Gelatin-based nanocomposite films were prepared by casting and characterized as a sensitive hybrid material to relative humidity changes in the development of electrical sensors. Zinc oxide nanoparticles (ZnO-NPs) and glycerol (Gly) were incorporated as reinforcing and plasticizing agents, respectively, and their effects on the sensibility property of films were investigated. The proposed sensors were investigated at 25 °C. The behavior of gelatin-based films as a function of water presence was analyzed in terms of moisture content (MC), water vapor permeability (WVP), and water contact angle (WCA). The incorporation of ZnO-NPs and Gly induced morphological and structural changes in the composite films. Increased WCA (7.51%) and reduced WVP (18%) were observed for the nanocomposite films. In addition, ZnO-NPs and Gly significantly contributed to a further improvement of relative humidity sensibility of films compared to the control film. Electrical characterizations, carried out at different environments for gelatin-based films, revealed a positive responsive relative humidity behavior of materials and a sensibility of 99.47% for hybrid materials, suggesting the development of a new promising nanocomposite material for monitoring relative humidity conditions at 25 °C.
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Papers by Veronica Calado