Papers by Maria Alejandra Garcia
Foods
Natural polymer-based adhesives are green alternatives, necessary to reduce the problems impacted... more Natural polymer-based adhesives are green alternatives, necessary to reduce the problems impacted by synthetic adhesives. Starch and gelatin have extraordinary potential for the synthesis of biobased adhesives. Citric acid (CA), a natural acid, induces the crosslinking and hydrolyzing of both gelatin and starch. In this sense, this work deals with the use of gelatin capsule residues as a promising material to produce biobased adhesives in combination with cassava starch in the presence of different CA concentrations characterizing their mechanical, physicochemical and microstructural properties. Depending on CA concentration, formulations adjusted to different applications can be obtained such as liquid and pressure-sensitive adhesive films. The inclusion of CA allows us not only to improve the applicability of the system since it modifies the flowability of the adhesives as evidenced by the observed changes in the viscosity (from 158.3 to 90.3 for formulations with 20 and 80% CA, r...
Future Foods
Fiber-enriched residues from cassava and ahipa roots starch extraction were analyzed by their str... more Fiber-enriched residues from cassava and ahipa roots starch extraction were analyzed by their structural, physicochemical, and techno-functional properties, before and after being subjected to overpressure thermal and ultrasound treatments. Thermal treatment efficiently reduced the residual starch content of both residues (up to 3.4 and 9.6% for ahipa and cassava, respectively), and its combination with ultrasound modified the structural and functional properties of cassava residue, while ahipa bagasse resulted almost unaffected. Ahipa residues swelling power (5.1-5.4 mL/g), WHC (6.9-7.3 g H 2 O/g), WBC (4.4-5.4 g H 2 O/g), and OBC (3.1-3.3 g oil/g) were in the range reported for several fiber-enriched ingredients, and resulted higher than those of cassava bagasse. Gel-forming capacity was observed for cassava residues coming from starch extraction, mainly due to their residual starch content. This property was lost after thermal treatment, but ultrasound restored the thermally driven gelling capacity. This recovery was associated with fiber structural changes revealed by microscopy, particle size distribution, and FTIR spectra. Based on their gelling properties, thermal and ultrasound-treated cassava bagasse could contribute to modify textural properties in low-calories fruit spreads. Although none of ahipa residues exhibited gelling capacity, their hydration properties and OBC can be applied in the formulation of fiber-enriched bakery products.
VI Congreso Internacional de Ciencia y Tecnología de los Alimentos (Córdoba, 2016), 2016
El objetivo del trabajo fue modificar físicamente almidón de mandioca con ultrasonido y estudiar ... more El objetivo del trabajo fue modificar físicamente almidón de mandioca con ultrasonido y estudiar su influencia sobre las propiedades estructurales y funcionales del polímero. Suspensiones al 5% p/v se trataron con ultrasonido durante 5, 10 y 20 min a 40% de amplitud y 750 W. El tratamiento se realizó a temperatura ambiente y en un baño con hielo. Observaciones al microscopio óptico evidenciaron un mayor hinchamiento de los gránulos luego del ultrasonido independientemente de la temperatura de tratamiento. Por SEM se observó que el ultrasonido indujo un daño físico superficial de los gránulos. El tratamiento afectó la distribución de tamaños, siendo los gránulos más pequeños los más susceptibles. Por DSC no se observaron diferencias significativas en la temperatura y la entalpía de gelatinización de las muestras tratadas respecto al control, excepto para las muestras tratadas durante 20 min. Cambios observados en la región 1075-1020 cm-1 de los espectros FTIR indicaron que el tratamiento modificó la cristalinidad de los almidones, resultados corroborados por difracción de rayos X. Las pastas presentaron un comportamiento pseudoplástico tixotrópico ajustando satisfactoriamente los datos experimentales con el modelo de Ostwald de Waele. Los espectros dinámicos mostraron las características viscoelásticas del sistema. La modificación física favoreció la retrogradación de las pastas. Esta tecnología simple y eco-compatible permitió inducir cambios estructurales en el almidón.
LWT, 2018
Cassava sour starch is a naturally-fermented, sun-dried product. It allows obtaining less dense b... more Cassava sour starch is a naturally-fermented, sun-dried product. It allows obtaining less dense bakery products than the native starch, being an appreciated gluten-free ingredient. The aim of this work was to study the effect of fermentation and drying method on the physicochemical and technological characteristics of cassava sour starch and to identify the relationships among those distinctive features that may condition their potential food applications. Natural fermentation following starch extraction could not be replaced by the use of a starter. Sour starches pastes showed lower apparent viscosities related to their lactic and/or butyric acid content, and a higher retrogradation tendency, mainly associated to sun-drying. The fermentation combined with the solar exposition represent a complex process that induce changes not easily observed on starch powders but clearly evidenced after gelatinization of the starch suspensions.
Food and Nutrition Sciences, 2017
The development of gluten-free foodstuffs with high nutritional quality components is an importan... more The development of gluten-free foodstuffs with high nutritional quality components is an important objective to achieve. Pachyrhizus ahipa is one of the few leguminous species that produce edible tuberous roots with high nutritional value. Thus, the aim of this work was to formulate biscuits containing corn starch and 125-350 g•kg −1 of P. ahipa flour (AF) and to study the main physicochemical properties related to their nutritional and technological quality as well as their sensory acceptability. The formulation containing 250 g of AF kg −1 was selected for improving the product nutritional quality (i.e. higher protein content) without an extensive modification of textural properties. A formulation replacing corn starch by cassava flour (250 g•kg −1) was also analyzed. In this case, ahipa and cassava biscuits showed maximum force and energy required to bite twice and three times higher than the control, respectively. Slight variations were observed in color (∆E and browning index). The overall acceptability of biscuits formulated with both flours was better scored than the control by a sensory panel. Principal component analysis allowed to relate quality attributes, chemical composition, and sensory characteristics of biscuits containing cassava or ahipa flours. The results indicated that ahipa flour could satisfactorily substitute part of the corn starch used in the formulations of gluten-free biscuits.
Journal of Agricultural and Food Chemistry, 2011
This work was focused on analyzing the effect produced by the addition of tannic acid as a crossl... more This work was focused on analyzing the effect produced by the addition of tannic acid as a crosslinking agent of chitosan matrix and the influence of the heat treatment applied. Taking into account those aspects relevant for packaging applications, thermal stability, mechanical properties, water resistance and kinetics of biodegradation of the film were monitored. The chemical crosslinking as well as the curing of the matrices have improved the mechanical properties and those related to the water affinity such as solubility, permeability and contact angle. Although both processes had an influence on the extent of the film degradation, these materials conserved their biodegradable character. Moreover, it was observed a synergistic effect of both chemical and physical treatments since the two processes in simultaneous caused further delay in the biodegradation. Consequently, in these materials the access to fungal attack and all those reactions mediated by the presence of water were restricted, which confirmed the higher stability of the matrices submitted to chemical or physical crosslinking.
Carbohydrate Polymers, 2008
Native starch can be chemically modified to improve its functionality and to expand its uses. Mod... more Native starch can be chemically modified to improve its functionality and to expand its uses. Modified starches were characterized and the rheological behavior of filmogenic suspensions was analyzed. The film forming capacity of different chemical modified corn starches was evaluated. Acetylated starch was selected by the characteristics of the resulted films; its optimum concentration was 5% w/w since their films exhibited the lowest water vapor permeability (WVP, 1.26 Â 10 À10 g/m s Pa). The effect of glycerol as plasticizer on film properties depend on its concentration, being 1.5% w/w those that allows to obtain the lowest WVP value (1.64 Â 10 À11 g/m s Pa), low film solubility in water and a more compact structure than those of unplasticized films. Mechanical behavior of plasticized acetylated starch films depends on glycerol concentration, being rigid and brittle the unplasticized ones, ductile those containing 1.5% w/w of glycerol and very flexible those with a higher plasticizer content.
Polymers
In this work, films containing AgNPs were obtained by different green synthesis techniques (AgNP ... more In this work, films containing AgNPs were obtained by different green synthesis techniques (AgNP in situ and AgNP L). The inclusion of nanoparticles in the starch matrix improved both mechanical and barrier properties. The migration of AgNPs from the nanocomposite material to three food simulants (water, 3% v/v acetic acid and 15% v/v ethanol) was studied. The experimental data were fitted by using different widely accepted mathematical models (Fickian, Ritger and Peppas, and Weibull), indicating that the AgNP migration followed a complex mechanism. The silver concentration (mg Ag per kg of simulant) that was released from the nanocomposite films was higher for the samples with AgNPs in situ than for those containing AgNP L. Likewise, the maximum release value (0.141 mg/dm2 for AgNPs in situ in acetic acid simulant) was lower than the limits proposed by the legislation (European Commission and MERCOSUR; 10 and 8 mg/dm2, respectively). The replacement of conventional plastic material...
Plastic mulch is used in various crops production in order to increase yield, extend growing seas... more Plastic mulch is used in various crops production in order to increase yield, extend growing season, weed control, increase fertilizers efficiency and improve soil conditions. However, since such plastics removal and disposal represent not only an additional cost, but also a source of environmental pollution, interest in starch-based materials as a viable alternative for this and other agricultural applications has raised in the last years. In this regard, films based on starch present several advantages: biodegradability, renewable-resource based and relatively low cost. The present work exhibit the results obtained in the development and study of biodegradable materials based on cassava starch reinforced with cassava bagasse, evaluating their biodegradability in soil and the effects of their exposure to UV -visible light cycles (photo-periods) for 60 days. Fibre inclusion resulted in more opaque and coloured films, with water vapour permeability a 53% higher, and increased maximum...
Emergent Materials, 2021
The greater awareness of non-renewable natural resources preservation needs has led to the develo... more The greater awareness of non-renewable natural resources preservation needs has led to the development of more ecological high-performance polymeric materials with new functionalities. In this regard, biobased composites are considered interesting options, especially those obtained from agro-industrial wastes and by-products. These are low-cost raw materials derived from renewable sources, which are mostly biodegradable and would otherwise typically be discarded. In this review, recent and innovative academic studies on composites obtained from biopolymers, natural fillers and active agents, as well as green-synthesized nanoparticles are presented. An in-depth discussion of biobased composites structures, properties, manufacture, and life-cycle assessment (LCA) is provided along with a wide up-to-date overview of the most recent works in the field with appropriate references. Potential uses of biobased composites from agri-food residues such as active and intelligent food packaging, agricultural inputs, tissue engineering, among others are described, considering that the specific characteristics of these materials should match the proposed application.
Journal of Polymers and the Environment, 2021
The use of agroindustry by-products as reinforcements and/or composites filler is an innovative a... more The use of agroindustry by-products as reinforcements and/or composites filler is an innovative and economically attractive option that is still under study. Hence, the present work aims to study composite foams based on cassava-starch and sunflower oil press cake (SOPC), an oil industry by-product, using urea as an additive to enhance the biocomposites foaming capacity. Filler content (0, 20, and 40 wt%) and urea addition effect on foam morphology, physical properties and mechanical behaviour were analysed and compared to a benchmark polystyrene (PS) foam. In comparison with conventional PS foams, biofoams containing urea presented comparable mechanical properties yet higher hydrophilicity. Besides, formulations containing SOPC resulted in denser and harder materials and higher water uptake capacity than starch-based foams. Results provide further insights into biobased biodegradable foams development using agroindustrial residues as raw material and urea as foaming agent, with promising characteristics for food packaging.
Matéria (Rio de Janeiro), 2018
RESUMEN La utilización de plásticos de cobertura o mulching en diversos cultivos puede aumentar l... more RESUMEN La utilización de plásticos de cobertura o mulching en diversos cultivos puede aumentar los rendimientos, extender la temporada de crecimiento, controlar malezas, aumentar la eficiencia de los fertilizantes y mejorar las condiciones del suelo. Sin embargo, luego de su uso son fuente de contaminación ambiental y su remoción genera un costo adicional. Para este fin y otras aplicaciones de interés agronómico el uso de películas a base de almidón es una alternativa viable debido a su biodegradabilidad, procedencia de un recurso renovable y relativo bajo costo. En el presente trabajo se exponen los resultados obtenidos en el desarrollo y estudio de materiales biodegradables a base de almidón de mandioca reforzados con el bagazo de la raíz, evaluando su biodegradabilidad en suelo y el efecto de la exposición de las mismas a ciclos de luz UV-visible (foto-períodos) durante 60 días. El agregado de fibra da lugar a películas más opacas y coloreadas, aumentó su permeabilidad al vapor ...
Matéria (Rio de Janeiro), 2018
RESUMEN Una de las líneas para el desarrollo de envases activos contempla la incorporación de age... more RESUMEN Una de las líneas para el desarrollo de envases activos contempla la incorporación de agentes antimicrobianos como el quitosano, polisacárido derivado del exoesqueleto de crustáceos. No obstante, su elevada masa molar restringe su difusión desde el envase hacia el alimento por lo que el empleo de oligómeros de características diferenciales es una alternativa interesante, aún poco investigada. El objetivo de este trabajo fue obtener películas activas a base de almidón de maíz termoplástico (TPS) mediante la incorporación de oligoquitosanos (OQ, masa molar = 290 g mol-1 y grado de polimerización = 2). Estos materiales fueron obtenidos mediante termo-compresión en una prensa hidráulica. Se realizaron ensayos de difusión de los OQ desde la matriz de TPS hacia un medio líquido con diferentes grados de acidez (pH = 3, 5 y 7). Las condiciones del medio líquido fueron seleccionadas según la acidez de una amplia variedad de alimentos. A partir de estos ensayos, se demostró la capacid...
Heliyon, 2019
A structural study about the changes induced by plasticization of native corn starch was carried ... more A structural study about the changes induced by plasticization of native corn starch was carried out in this work. The influence of talc nanoparticles presence during starch thermal processing was also evaluated. Macroscopic observation of the granules appearance evolution during melt-mixing and thermo-compression was supported by a theoretical description related to these processing methods. Melt-mixing induced a polymorphic transformation from A-to V h-type and a reduction in the degree of crystallinity. Homogenous appearance of the plasticized starch was in accordance to the disruption of granules integrity, evidenced by SEM. This observation agreed to the distinctive XRD pattern of plasticized starch from unprocessed granules. Talc incorporation did not require the adjustment of processing parameters in order to obtain a homogenous thermoplastic material, with an adequate particles distribution within the matrix. Regardless talc presence, plasticized starch presented a V h-type crystalline structure. Thermo-compression led to particles alignment promoted by talc laminar morphology.
Food Packaging and Shelf Life, 2017
Antimicrobial biodegradable films based on thermoplastic corn starch (TPS) and chitosan oligomers... more Antimicrobial biodegradable films based on thermoplastic corn starch (TPS) and chitosan oligomers (CO) were obtained in order to develop a package prototype for perishable food products. Active films were fabricated thermo-compressing a sandwiched structure constituted by a thin layer of an oligomers enriched solution between two TPS films, previously made by melt-mixing and hot-pressing. Regarding enriched solution, it was obtained by dissolving oligomers in diluted acetic acid. Final material was characterized, determining its physical and optical properties, as well as, studying its microstructure. By diffusion assays it was demonstrated the capability of CO to migrate from the active film towards the aqueous simulant media. Moreover, oligomers were able to diffuse from the matrix, regardless the aqueous medium acidity. Experimental data of diffusion assays were fitted using a mathematical model, estimating diffusion coefficients at three studied pH values (3, 5, and 7). Active film was used to obtain sachets to package perishable foods such as strawberries, ricotta, and flavored breads, which were stored for 7 days under controlled conditions. Antimicrobial capacity of active sachets was corroborated through molds and yeast counts in the stored food products. Additionally, it was demonstrated that CO incorporation to the packaging material resulted in a more efficient way to inhibit microbial development than the spraying technique.
ACS Sustainable Chemistry & Engineering, 2018
Foods
Food loss and waste occur for many reasons, from crop processing to household leftovers. Even tho... more Food loss and waste occur for many reasons, from crop processing to household leftovers. Even though some waste generation is unavoidable, a considerable amount is due to supply chain inefficiencies and damage during transport and handling. Packaging design and materials innovations represent real opportunities to reduce food waste within the supply chain. Besides, changes in people’s lifestyles have increased the demand for high-quality, fresh, minimally processed, and ready-to-eat food products with extended shelf-life, that need to meet strict and constantly renewed food safety regulations. In this regard, accurate monitoring of food quality and spoilage is necessary to diminish both health hazards and food waste. Thus, this work provides an overview of the most recent advances in the investigation and development of food packaging materials and design with the aim to improve food chain sustainability. Enhanced barrier and surface properties as well as active materials for food c...
Polymers, 2021
Blueberries are highly appreciated for their high antioxidant content but are also particularly s... more Blueberries are highly appreciated for their high antioxidant content but are also particularly susceptible to fungal deterioration. In this work, corn starch and chitosan, byproducts of the fishing industry, as well as active compounds obtained from citrus processing waste were used to obtain active biodegradable film packaging. Blueberries were packed in corn starch–chitosan (CS:CH) films and in active films containing lemon essential oil (LEO) or grapefruit seed extract (GSE). The effects of film packaging on the quality parameters of berries and the fungal incidence of disease during storage were studied and compared to benchmark materials. A conservation assay simulating transport and commercialization conditions was conducted. Blueberries packed in CS:CH films showed antioxidant capacity values closer to those packed in commercial PET containers (Clamshells), preserving 84.8% of the initial antioxidants content. Fruit packed in LEO films exhibited the greatest weight loss and ...
Fil: Castillo, Luciana Andrea. Universidad Nacional del Sur; Argentina. Consejo Nacional de Inves... more Fil: Castillo, Luciana Andrea. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Bahia Blanca. Planta Piloto de Ingenieria Quimica (i); Argentina
Procedia Materials Science, 2015
Composite films of TPS with talc nanoparticles were obtained by thermo-compression in order to st... more Composite films of TPS with talc nanoparticles were obtained by thermo-compression in order to study the effect of this filler on structure, optical, and thermal properties. TPS-talc films showed good appearance and homogeneous thickness. Talc addition increased the amount of rigid phase in nanocomposite films, thus their cross-sections resulted more irregular than those of TPS ones. Talc preferential orientation within matrix and good compatibility between particles and TPS were evidenced. TEM observation showed scattered randomly dispersed individual talc platelets. Matrix crystallinity degree was not significantly affected by particles presence. Nanocomposite films were optically transparent due to the laminar morphology and nanosized particles. Materials microstructure presented glycerol-and starch-rich domains. Talc incorporation higher than 3 % w/w increased softening resistance of nanocomposites as stated by DMA assays. TPS relaxation temperature of glycerol-rich phase was shifted to higher values since talc nanoparticles reduce starch chains mobility.
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Papers by Maria Alejandra Garcia