scholarly journals Preparation and Physicochemical Properties of Modified Corn Starch – Chitosan Biodegradable Films

Author(s):  
Enrique Javier Jiménez-Regalado ◽  
Carolina Caicedo ◽  
Abril Fonseca-García ◽  
Claudia Cecilia Rivera-Vallejo ◽  
Rocio Yaneli Aguirre-Loredo

Starch is a biopolymer with wide potential for the generation of new biodegradable packages due to its high availability and low price. However, due to its weak functional properties, it is necessary to limit the interaction of some hydroxyl, and to evaluate blends with other polymers to improve their performance. Glycerol plasticized acetylated corn starch films were developed by the casting method, and the impact of incorporating chitosan (TPS:CH) at various proportions (75:25, 50:50, and 25:75 v/v) was studied. The effect of the chitosan ratios on the films' physical, mechanical, water vapor barrier, and thermal properties was evaluated. Chitosan protonated amino groups promote the formation of intermolecular bonds, improving the tensile strength, the thermal stability, the water adsorption capacity, and the gas barrier of starch films. Where the film composed of TPS25-CH75 was the one that presented the best barrier to water vapor. These composite films are a good option for development of biodegradable packaging.

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4431
Author(s):  
Enrique Javier Jiménez-Regalado ◽  
Carolina Caicedo ◽  
Abril Fonseca-García ◽  
Claudia Cecilia Rivera-Vallejo ◽  
Rocio Yaneli Aguirre-Loredo

Starch is a biopolymer with enormous potential for generating new biodegradable packages due to its easy availability and low cost. However, due to its weak functional properties, limitation of its interaction with some hydroxyl groups and evaluation of blends with other polymers are necessary in order to improve its performance. Glycerol-plasticized acetylated corn starch films were developed using the casting method, and the impact of incorporating chitosan (TPS:CH) in various proportions (75:25, 50:50, and 25:75 v/v) was studied in the present research. The effect of chitosan ratios on the physical, mechanical, water-vapor barrier, and thermal properties of the film was studied. Chitosan-protonated amino groups promoted the formation of intermolecular bonds, improving tensile strength, thermal stability, hydrophobicity, water adsorption capacity, and the gas barrier of starch films. The results show that the film composed of TPS25-CH75 proved to be the best barrier to water vapor; thus, these composite films are excellent choices for developing biodegradable packaging for the food industry.


2020 ◽  
Author(s):  
Olivia López ◽  
María E. Villanueva ◽  
Guillermo J. Copello ◽  
Marcelo A Villar

Abstract Biodegradable films based on thermoplastic corn starch (TPS) and copper particles with antimicrobial capacity were developed. Copper nanoparticles (Cu) and silica coated copper microparticles (Si-Cu) in the range of 0.25 to 5 % were used. Composite films were obtained by melt-mixing and subsequent thermo-compression. Particles distribution within TPS matrix and the presence of some pores and cracks, induced by Si-Cu particles, was evaluated by SEM. The presence of both fillers gave to composite films a brown pigmentation and decreased their transparency; these effects were more pronounced at higher particles concentrations. Regarding mechanical properties, copper particles at 1 and 5 % acted as reinforcing agents increasing the maximum tensile strength but their presence lead to a decrease in elongation at break, affecting films ductility. Composites inhibited the growth of Gram+ and Gram- bacteria, demonstrating their antimicrobial capacity. Copper effectively migrated to a simulant of aqueous foods and naked particles concentration in the simulant medium resulted higher than the minimum inhibitory concentration for bacteria. The characteristics and properties of developed composite films make them an interesting material for food primary packaging, mainly for meat fresh products.


2020 ◽  
Author(s):  
Olivia López ◽  
María E. Villanueva ◽  
Guillermo J. Copello ◽  
Marcelo A Villar

Abstract Biodegradable films based on thermoplastic corn starch (TPS) and copper particles with antimicrobial capacity were developed. Copper nanoparticles (Cu) and silica coated copper microparticles (Si-Cu) in the range of 0.25 to 5 % were used. Composite films were obtained by melt-mixing and subsequent thermo-compression. Particles distribution within TPS matrix and the presence of some pores and cracks, induced by Si-Cu particles, was evaluated by SEM. The presence of both fillers gave to composite films a brown pigmentation and decreased their transparency; these effects were more pronounced at higher particles concentrations. Regarding mechanical properties, copper particles at 1 and 5 % acted as reinforcing agents increasing the maximum tensile strength but their presence lead to a decrease in elongation at break, affecting films ductility. Composites inhibited the growth of Gram+ and Gram- bacteria, demonstrating their antimicrobial capacity. Copper effectively migrated to a simulant of aqueous foods and naked particles concentration in the simulant medium resulted higher than the minimum inhibitory concentration for bacteria.The characteristics and properties of developed composite films make them an interesting material for food primary packaging, mainly for meat fresh products.


2020 ◽  
Author(s):  
Olivia López ◽  
María E. Villanueva ◽  
Guillermo J. Copello ◽  
Marcelo A Villar

Abstract Biodegradable films based on thermoplastic corn starch (TPS) and copper particles with antimicrobial capacity were developed. Copper nanoparticles (Cu) and silica coated copper microparticles (Si-Cu) in the range of 0.25 to 5 % were used. Composite films were obtained by melt-mixing and subsequent thermo-compression. Particles distribution within TPS matrix and the presence of some pores and cracks, induced by Si-Cu particles, was evaluated by SEM. The presence of both fillers gave composite films a brown pigmentation and decreased their transparency; these effects were more pronounced at higher particles concentrations. Regarding mechanical properties, copper particles at 1 and 5 % acted as reinforcing agents increasing the maximum tensile strength but their presence lead to a decrease in elongation at break, affecting films ductility. Composites inhibited the growth of Gram+ and Gram- bacteria, demonstrating their antimicrobial capacity. Copper effectively migrated to a simulant of aqueous foods and naked particles concentration in the simulant medium resulted higher than the minimum inhibitory concentration for bacteria. The characteristics and properties of developed composite films make them an interesting material for food primary packaging, mainly for meat fresh products.


ForScience ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. e00958
Author(s):  
Priscila Ferreira de Sales ◽  
Yago Ribeiro de Oliveira Silva ◽  
Leonardo Silva Santos Lapa ◽  
Francisco Hélcio Canuto Amaral

Foram sintetizados filmes biodegradáveis empregando quantidades distintas de amido de milho, glicerina e extrato de própolis-verde em um planejamento fatorial completo com três pontos centrais. Os materiais foram analisados com base em duas propriedades: físicas (espessura, densidade, gramatura e índice de intumescimento) e óptica (transparência). Em todas as propriedades analisadas foi empregado o gráfico de Pareto com a finalidade de verificar o efeito das variáveis e de suas interações. Foram construídas superfícies de resposta para as interações e regressões que foram significativas ao teste conduzido com 95% de confiança. Os resultados permitiram evidenciar que dentre os parâmetros avaliados, o amido de milho foi o que mais influenciou na determinação da espessura, densidade, gramatura e transparência, justificado pela maior quantidade inserida durante a síntese e por ser empregado como agente formador. Por outro lado, na determinação do índice de intumescimento, a glicerina foi o fator de maior influência, já que a mesma é adicionada como agente plastificante. Após a avaliação dos filmes, foram selecionados os que apresentaram as características mais adequadas para aplicação na conservação de bananas-prata (Musa spp.). Os resultados foram promissores na medida em que as frutas embaladas apresentaram menor perda de massa, quando comparadas à amostra sem embalagem, indicando que os biofilmes produzidos são adequados por impedirem as reações de oxidação e deterioração de alimentos. Palavras-chave: Biofilmes. Ferramentas quimiométricas. Conservação de bananas.   Characterization and application of biodegradable starch films incorporated with propolis-green extract Abstract Biodegradable films were synthesized using different amounts of corn starch, glycerin and green propolis extract in a complete factorial design with three central points. The materials obtained were analyzed based of two properties: physical (thickness, density, weight and swelling index) and optics (transparency). In all the properties analyzed, the Pareto graph was used in order to verify the effect of the variables and their interactions. Response surfaces were built for interactions and regressions that were significant to the test conducted with 95% confidence. The results showed that among the evaluated parameters, corn starch was the one that most influenced the determination of thickness, density, weight and transparency, justified by the greater quantity inserted during the synthesis and for being used as a forming agent. On the other hand, in the determination of the swelling index, glycerin was the factor of greatest influence, since it is added as a plasticizer. After the evaluation of the synthesized films, those that had the most suitable characteristics for application in the conservation of silver bananas (Musa spp.) were selected. The results were promising insofar as the packaged fruits show less loss of mass, when compared to the sample without packaging, indicating that the biofilms produced are adequate for preventing oxidation and food spoilage reactions. Keywords: Biofilms. Chemometric tools. Banana´s conservation.


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1606
Author(s):  
Peng Yin ◽  
Jinglong Liu ◽  
Wen Zhou ◽  
Panxin Li

To improve the functional properties of starch-based films, chitin (CH) was prepared from shrimp shell powder and incorporated into corn starch (CS) matrix. Before blending, maleic anhydride (MA) was introduced as a cross-linker. Composite CS/MA-CH films were obtained by casting-evaporation approach. Mechanical property estimation showed that addition of 0–7 wt % MA-CH improved the tensile strength of starch films from 3.89 MPa to 9.32 MPa. Elongation at break of the films decreased with the addition of MA-CH, but the decrease was obviously reduced than previous studies. Morphology analysis revealed that MA-CH homogeneously dispersed in starch matrix and no cracks were found in the CS/MA-CH films. Incorporation of MA-CH decreased the water vapor permeability of starch films. The water uptake of the films was reduced when the dosage of MA-CH was below 5 wt %. Water contact angles of the starch films increased from 22° to 86° with 9 wt % MA-CH incorporation. Besides, the composite films showed better inhibition effect against Escherichia coli and Staphylococcus aureus than pure starch films.


2013 ◽  
Vol 469 ◽  
pp. 156-161 ◽  
Author(s):  
Hong Pan ◽  
Dan Xu ◽  
Qin Liu ◽  
Hui Qing Ren ◽  
Min Zhou

Starch-based nanocomposite films were fabricated by the incorporation of different amounts of nanodiamond (ND) particles. These films were characterized by SEM, FT-IR, TGA, tensile testing and water vapor permeability measurement. It was observed that at low loadings, ND dispersed well in starch matrix. However, as the loading amount increased, aggregates as large as several micrometers appeared. The physical blending of ND with starch didnt change the thermal degradation mechanisms of starch films, only increased the char residues. As the ND loading increased, the tensile strength of composite films increased but the elongation at break decreased. However, the water vapor permeability increased as the loading of ND increased due to the increased microspores in films. With further modifications, ND may be considered as a novel of biocompatible nanofillers for reinforcement of biopolymers for food packaging applications.


2012 ◽  
Vol 506 ◽  
pp. 311-314 ◽  
Author(s):  
W. Pimpa ◽  
C. Pimpa ◽  
P. Junsangsree

Fresh durian seed consists largely of starch and can be considered such a suitable raw material for producing biodegradable films. The aim of this work was to develop biodegradable films based on durian seed starch (DSS) and to characterize their water barrier, microscopic and mechanical properties. DSS films were prepared by casting with glycerol as plasticizer. Corn starch and cassava starch, commonly used in food processing, were chosen to prepare films and compare their properties to the DSS-based films. Using a second biopolymer, carboxymethyl cellulose (CMC), in the DSS based composite has been studied as a strategy to improve their important properties. Water vapor permeability and elongation values were improved significantly (p<0.05) when 5% (w/w DSS) CMC was incorporated. Therefore, preparing biodegradable films from DSS is a new alternative for using this raw material which is sometimes much cheaper than commercial starches


2021 ◽  
Vol 11 (18) ◽  
pp. 8433
Author(s):  
Pedro A. V. Freitas ◽  
Carla I. La Fuente Arias ◽  
Sergio Torres-Giner ◽  
Chelo González-Martínez ◽  
Amparo Chiralt

In the present study, agro-food waste derived rice straw (RS) was valorized into cellulose microfibers (CMFs) using a green process of combined ultrasound and heating treatments and were thereafter used to improve the physical properties of thermoplastic starch films (TPS). Mechanical defibrillation of the fibers gave rise to CMFs with cumulative frequencies of length and diameters below 200 and 5–15 µm, respectively. The resultant CMFs were successfully incorporated at, 1, 3, and 5 wt% into TPS by melt mixing and also starch was subjected to dry heating (DH) modification to yield TPS modified by dry heating (TPSDH). The resultant materials were finally shaped into films by thermo-compression and characterized. It was observed that both DH modification and fiber incorporation at 3 and 5 wt% loadings interfered with the starch gelatinization, leading to non-gelatinized starch granules in the biopolymer matrix. Thermo-compressed films prepared with both types of starches and reinforced with 3 wt% CMFs were more rigid (percentage increases of ~215% for TPS and ~207% for the TPSDH), more resistant to break (~100% for TPS and ~60% for TPSDH), but also less extensible (~53% for TPS and ~78% for TPSDH). The incorporation of CMFs into the TPS matrix at the highest contents also promoted a decrease in water vapor (~15%) and oxygen permeabilities (~30%). Finally, all the TPS composite films showed low changes in terms of optical properties and equilibrium moisture, being less soluble in water than the TPSDH films.


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