Changes induced by UV radiation in the presence of sodium benzoate in films formulated with polyvinyl alcohol and carboxymethyl cellulose

This work was focused on: i) developing single and blend films based on carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVOH) studying their properties, ii) analyzing the interactions between CMC and PVOH and their modifications UV-induced in the presence of sodium benzoate (SB), and iii) evaluating the antimicrobial capacity of blend films containing SB with and without UV treatment. Once the blend films with SB were exposed to UV radiation, they exhibited lower moisture content as well as a greater elongation at break and rougher surfaces compared to those without treatment. Considering oxygen barrier properties, the low values obtained would allow their application as packaging with selective oxygen permeability. Moreover, the characteristics of the amorphous phase of the matrix prevailed with a rearrangement of the structure of the polymer chain, causing a decrease of the crystallinity degree. These results were supported by X-rays and DSC analysis. FT-IR spectra reflected some degree of polymer–polymer interaction at a molecular level in the amorphous regions. The incorporation of sodium benzoate combined with UV treatment in blend films was positive from the microbial point of view because of the growth inhibition of a wide spectrum of microorganisms. From a physicochemical perspective, the UV treatment of films also changed their morphology rendering them more insoluble in water, turning the functionalized blend films into a potential material to be applied as food packaging.Fil: Villarruel, S.. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Giannuzzi, Leda. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Rivero, Sandra G. M.. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Pinotti, Adriana Noemi. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

Estudio y aplicación de películas activas a base de quitosano

El quitosano es un material biocompatible, biodegradable, no-tóxico, de gran aplicación tanto en el campo de la biotecnología, la medicina, como en la industria alimentaria y en el área farmacéutica, cosmética, y de tecnología de envases. Las películas biodegradables a partir de recursos naturales no pretenden sustituir las aplicaciones de los polímeros sintéticos sino plantear un aprovechamiento integral y eficiente de los recursos. Su utilización en el área de envases depende fundamentalmente de sus propiedades de barrera y mecánicas. Asimismo, las investigaciones realizadas en el campo de la medicina y en el área farmacéutica demostraron que las matrices de quitosano son altamente efectivas en la liberación controlada de componentes activos, debido a su naturaleza hidrofílica y a sus particulares propiedades. El objetivo del presente trabajo de Tesis fue desarrollar y aplicar películas biodegradables a base de quitosano abordando diferentes estrategias para modificar sus propiedades funcionales.Material digitalizado en SEDICI gracias a la Biblioteca de la Facultad de Ingeniería (UNLP).Facultad de Ingenierí

Under the same sky with Amanar

Due to its technological, scientific and cultural dimensions, astronomy is a unique discipline to help achieve the United Nations Sustainable Development Goals. According to the United Nations High Commissioner for Refugees (UNHCR), there are currently nearly 30 million refugees in the world. While there are many (and very necessary) programmes supporting their basic needs, different indicators suggest that the resolution to refugee and internal displacement situations require not only humanitarian interventions, but also development-led actions. One of these initiatives is Amanar: Under the Same Sky, a project designed to support the Sahrawi refugee community by using astronomy to enhance their resilience and engagement in the community, through skill development and self-empowerment activities.Comment: 5 pages, 2 figures. Comment published on Nature Astronom

Functional Jelly Beans Based On Hydrocolloids And Citrus Cremogenates

Jelly beans were obtained from sugar, gelling agents, and citric cremogenates as source of bioactive compounds. To the best of our knowledge, the blends of modified starch and low methoxyl pectin (LMP) as well as the effect of citric cremogenates on the formulation of confectionery gels and their functional properties have hardly been reported. This work was focused on: i) obtaining cremogenates from different citrus fruits and characterizing them physicochemically; ii) formulating jelly beans based on acetylated starch, LMP, and cremogenate; iii) assessing the quality attributes and global acceptability. Furthermore, the changes on rheological behaviour due to cremogenate addition and calcium-induced gelation in composite model systems were studied. Viscoelasticity studies confirmed the type-gel structure of the formulated systems. Likewise, rheological results correlated with TPA profiles of jelly beans. General acceptability scores were 6.84 for formulations containing orange cremogenate and 5.72 for grapefruit ones. Composite developed systems have a protective effect of ascorbic acid exhibiting a slight reduction during the drying step especially in the case of samples containing grapefruit cremogenate. The functionalization of the matrix with calcium, involved in the chemical gelation mechanism of pectin, can incorporate this mineral in the final product, being this relevant from a nutritional point of viewCentro de Investigación y Desarrollo en Criotecnología de Alimento

Impregnation of kraft paper support with polylactic acid multilayers

PLA coating on Kraft paper is very promising systems for food packaging, and has potential environmental advantages over conventional synthetic paper coatings. This work was focused on: (i) analyzing the physicochemical, thermal and microstructural properties of PLA films; (ii) developing and studying multilayer systems obtained by impregnation of Kraft paper with different layers of PLA solution; (iii) evaluating the influence of PLA layers on the support cellulosic properties. The PLA coating improves packaging material performance and hence the functional properties of Kraft paper. The impregnation of hygroscopic materials as the Kraft paper with PLA was an alternative interesting to obtain more hydrophobic matrices. The assembled materials attained were heat-sealed. Furthermore, the use of PLA adds to potential food applications, a renewable resource value obtained from sources agricultural. The design of this multilayer support also allows its extension to other media such as paperboard. Moreover, the addition of 4 or 5 layers favourably modified the assembled system properties. Increasing even further the number of PLA layers, system properties hardly underwent a significant improvement. Consequently, the selection of the number of PLA layers would be a response to a relationship of commitment between the increase in the cost and the enhancement of the properties.Facultad de Ciencias Exacta

Functional Jelly Beans Based On Hydrocolloids And Citrus Cremogenates

Jelly beans were obtained from sugar, gelling agents, and citric cremogenates as source of bioactive compounds. To the best of our knowledge, the blends of modified starch and low methoxyl pectin (LMP) as well as the effect of citric cremogenates on the formulation of confectionery gels and their functional properties have hardly been reported. This work was focused on: i) obtaining cremogenates from different citrus fruits and characterizing them physicochemically; ii) formulating jelly beans based on acetylated starch, LMP, and cremogenate; iii) assessing the quality attributes and global acceptability. Furthermore, the changes on rheological behaviour due to cremogenate addition and calcium-induced gelation in composite model systems were studied. Viscoelasticity studies confirmed the type-gel structure of the formulated systems. Likewise, rheological results correlated with TPA profiles of jelly beans. General acceptability scores were 6.84 for formulations containing orange cremogenate and 5.72 for grapefruit ones. Composite developed systems have a protective effect of ascorbic acid exhibiting a slight reduction during the drying step especially in the case of samples containing grapefruit cremogenate. The functionalization of the matrix with calcium, involved in the chemical gelation mechanism of pectin, can incorporate this mineral in the final product, being this relevant from a nutritional point of viewCentro de Investigación y Desarrollo en Criotecnología de Alimento

Impregnation of kraft paper support with polylactic acid multilayers

PLA coating on Kraft paper is very promising systems for food packaging, and has potential environmental advantages over conventional synthetic paper coatings. This work was focused on: (i) analyzing the physicochemical, thermal and microstructural properties of PLA films; (ii) developing and studying multilayer systems obtained by impregnation of Kraft paper with different layers of PLA solution; (iii) evaluating the influence of PLA layers on the support cellulosic properties. The PLA coating improves packaging material performance and hence the functional properties of Kraft paper. The impregnation of hygroscopic materials as the Kraft paper with PLA was an alternative interesting to obtain more hydrophobic matrices. The assembled materials attained were heat-sealed. Furthermore, the use of PLA adds to potential food applications, a renewable resource value obtained from sources agricultural. The design of this multilayer support also allows its extension to other media such as paperboard. Moreover, the addition of 4 or 5 layers favourably modified the assembled system properties. Increasing even further the number of PLA layers, system properties hardly underwent a significant improvement. Consequently, the selection of the number of PLA layers would be a response to a relationship of commitment between the increase in the cost and the enhancement of the properties.Facultad de Ciencias Exacta

Changes induced by UV radiation in the presence of sodium benzoate in films formulated with polyvinyl alcohol and carboxymethyl cellulose

This work was focused on: i) developing single and blend films based on carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVOH) studying their properties, ii) analyzing the interactions between CMC and PVOH and their modifications UV-induced in the presence of sodium benzoate (SB), and iii) evaluating the antimicrobial capacity of blend films containing SB with and without UV treatment. Once the blend films with SB were exposed to UV radiation, they exhibited lower moisture content as well as a greater elongation at break and rougher surfaces compared to those without treatment. Considering oxygen barrier properties, the low values obtained would allow their application as packaging with selective oxygen permeability. Moreover, the characteristics of the amorphous phase of the matrix prevailed with a rearrangement of the structure of the polymer chain, causing a decrease of the crystallinity degree. These results were supported by X-rays and DSC analysis. FT-IR spectra reflected some degree of polymer–polymer interaction at a molecular level in the amorphous regions. The incorporation of sodium benzoate combined with UV treatment in blend films was positive from the microbial point of view because of the growth inhibition of a wide spectrum of microorganisms. From a physicochemical perspective, the UV treatment of films also changed their morphology rendering them more insoluble in water, turning the functionalized blend films into a potential material to be applied as food packaging.Centro de Investigación y Desarrollo en Criotecnología de AlimentosFacultad de Ciencias ExactasFacultad de Ingenierí

Physical and Chemical Treatments on Chitosan Matrix to Modify Film Properties and Kinetics of Biodegradation

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.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Criotecnología de AlimentosFacultad de Ingenierí