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

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

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

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

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.Fil: Rivero, Sandra G. M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones en Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Garcia, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones en Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Pinotti, Adriana Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones en Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Universidad Nacional de La Plata. Facultad de Ingenieria; Argentin

Structural Insight into Chitosan Supports Functionalized with Nanoparticles

The incorporation of suspensions of nanoparticles functionalized with gallic acid (GA) was used as a strategy to obtain nanocomposite active films with different both, chitosan: tripolyphosphate (CH:TPP) and nanoparticles:chitosan (N:CH) ratios. The thermal analysis carried out by modulated differential scanning calorimetry (MDSC) allowed observing the shift of an endothermic event towards higher temperatures with a greater N:CH ratio. Analyzing ATR-FTIR spectra through-principal component analysis (PCA) can be inferred that the incorporation of the nanoparticles produced a discrimination of the samples into clusters when the region 1400-1700 cm-1 was considered.The decrease in crystalline size with the inclusion of nanoparticles (NA and NB), proved the existence of interactions among CH, TPP, and GA, resulting in a more amorphous structure. The positron annihilation lifetime spectroscopy (PALS) technique was adequate to correlate the glass transition temperatures (Tg) obtained by using the MDSC technique with parameters τ2 and I2 ascribed to the annihilation of positrons in the interface.The cross-section of nanocomposites obtained by scanning electron microscopy (SEM) clearly showed a homogeneous distribution of the nanoparticles without aggregation suggesting their compatibility with the CH matrix. By virtue of the obtained results, the nanocomposites with the greatest nanoparticle proportion and the highest TPP concentration attained significant modifications in relation to CH matrices, because of the crosslinking of the biopolymer with GA and TPP.Centro de Investigación y Desarrollo en Criotecnología de AlimentosInstituto de Física La Plat

Structural Insight into Chitosan Supports Functionalized with Nanoparticles

The incorporation of suspensions of nanoparticles functionalized with gallic acid (GA) was used as a strategy to obtain nanocomposite active films with different both, chitosan: tripolyphosphate (CH:TPP) and nanoparticles:chitosan (N:CH) ratios. The thermal analysis carried out by modulated differential scanning calorimetry (MDSC) allowed observing the shift of an endothermic event towards higher temperatures with a greater N:CH ratio. Analyzing ATR-FTIR spectra through-principal component analysis (PCA) can be inferred that the incorporation of the nanoparticles produced a discrimination of the samples into clusters when the region 1400-1700 cm-1 was considered.The decrease in crystalline size with the inclusion of nanoparticles (NA and NB), proved the existence of interactions among CH, TPP, and GA, resulting in a more amorphous structure. The positron annihilation lifetime spectroscopy (PALS) technique was adequate to correlate the glass transition temperatures (Tg) obtained by using the MDSC technique with parameters τ2 and I2 ascribed to the annihilation of positrons in the interface.The cross-section of nanocomposites obtained by scanning electron microscopy (SEM) clearly showed a homogeneous distribution of the nanoparticles without aggregation suggesting their compatibility with the CH matrix. By virtue of the obtained results, the nanocomposites with the greatest nanoparticle proportion and the highest TPP concentration attained significant modifications in relation to CH matrices, because of the crosslinking of the biopolymer with GA and TPP.Centro de Investigación y Desarrollo en Criotecnología de AlimentosInstituto de Física La Plat