scholarly journals Influence of Starch Composition and Molecular Weight on Physicochemical Properties of Biodegradable Films

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1084 ◽  
Author(s):  
Daniel Domene-López ◽  
Juan Carlos García-Quesada ◽  
Ignacio Martin-Gullon ◽  
Mercedes G. Montalbán

Thermoplastic starch (TPS) films are considered one of the most promising alternatives for replacing synthetic polymers in the packaging field due to the starch biodegradability, low cost, and abundant availability. However, starch granule composition, expressed in terms of amylose content and phosphate monoesters, and molecular weight of starch clearly affects some film properties. In this contribution, biodegradable TPS films made from potato, corn, wheat, and rice starch were prepared using the casting technique. The effect of the grain structure of each starch on microstructure, transparency, hydration properties, crystallinity, and mechanical properties of the films, was evaluated. Potato starch films were the most transparent and corn starch films the most opaque. All the films had homogeneous internal structures—highly amorphous and with no pores, both of which point to a good starch gelatinization process. The maximum tensile strength (4.48–8.14 MPa), elongation at break (35.41–100.34%), and Young’s modulus (116.42–294.98 MPa) of the TPS films were clearly influenced by the amylose content, molecular weight, and crystallinity of the film. In this respect, wheat and corn starch films, are the most resistant and least stretchable, while rice starch films are the most extensible but least resistant. These findings show that all the studied starches can be considered suitable for manufacturing resistant and flexible films with similar properties to those of synthetic low-density polyethylene (LDPE), by a simple and environmentally-friendly process.

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 614 ◽  
Author(s):  
Jordanna S. Monteiro ◽  
Priscila Farage ◽  
Renata Puppin Zandonadi ◽  
Raquel B. A. Botelho ◽  
Livia de L. de Oliveira ◽  
...  

This study aimed to perform a systematic review on gluten-free bread formulations using specific volumes as a quality indicator. In this systematic review, we identified 259 studies that met inclusion criteria. From these studies, 43 met the requirements of having gluten-free bread with a specific volume greater than or equal to 3.5 cm3/g. Other parameters such as the texture profile, color (crumb and crust), and sensory analysis examined in these studies were presented. The formulations that best compensated the lack of the gluten-network were based on the combination of rice flour, rice flour with low amylose content, maize flour, rice starch, corn starch, potato starch, starch with proteins and added with transglutaminase (TGase), and hydrocolloids like hydroxypropylmethylcellulose (HPMC). Of the 43 studies, three did not present risk of bias, and the only parameter evaluated in common in the studies was the specific volume. However, it is necessary to jointly analyze other parameters that contribute to the quality, such as texture profile, external and internal characteristics, acceptability, and useful life of the bread, especially since it is a product obtained through raw materials and unconventional ingredients.


2021 ◽  
Vol 18 (38) ◽  
pp. 137-148
Author(s):  
Alvaro ARRIETA

Background: Solid biopolymer electrolytes are a type of material with high technological potential used in the development of solar cells, batteries, fuel cells, among others, due to their biodegradable nature and low environmental impact. Aim: This study aimed to evaluate the effect of the botanical origin of the starch used to prepare solid biopolymeric electrolyte films on its electrochemical and thermal properties and to establish the variations in thermal decomposition temperatures and redox potentials depending on the botanical origin of the starch used. Methods: Films of solid biopolymer electrolyte were made by thermochemical synthesis processes using corn starch, cassava starch, potato starch, glycerol, polyethylene glycol, and glutaraldehyde as plasticizers and lithium perchlorate salt. The synthesis solutions were taken to an oven at 70 °C for 48 hours. The films were characterized electrochemically by cyclic voltammetry using a dry electrochemical cell and thermally by differential scanning calorimetry and thermogravimetric analysis. Results and Discussion: The results showed that the electrochemical behavior of the films was similar in terms of registered redox processes. However, the potential values of the oxidation and reduction were different, as are the stability and intensity of the processes. On the other hand, the thermal analysis allowed establishing two decomposition processes in each of the films studied; the first process was due to dehydration and depolymerization phenomena in the films. The temperatures recorded were 59.0 °C, 58.9 °C, and 89.9 °C for potato starch, cassava starch, and corn starch films. The second process evidenced the thermal decomposition at different temperatures, 267.7 °C in potato starch films, 280.6 °C in corn starch films, and 287.1 °C in cassava starch films. Conclusions: It could be concluded that the botanical origin of the starch used in the synthesis of solid biopolymer electrolyte films affects its behavior and electrochemical and thermal stability.


Fibers ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 99 ◽  
Author(s):  
Fabrizio Scognamiglio ◽  
Daniele Mirabile Gattia ◽  
Graziella Roselli ◽  
Franca Persia ◽  
Ugo De Angelis ◽  
...  

Dry fibers coming from garden waste, originating from Opuntia ficus indica, were introduced in amounts of either 8 or 16 wt % into a self-produced thermoplastic starch (TPS) based on potato starch and glycerol. Thermal (differential scanning calorimetry, DSC), mechanical (tensile tests), and morphological characterization with scanning electron microscopy (SEM) and performing energy-dispersive X-ray spectrometry (microanalysis) were carried out. The results indicated that the uneven distribution and variable geometry of fibers introduced led to a reduction of tensile stress and strain with respect to pure TPS. However, the positive effects of prolonged mixing and increased thickness were highlighted, which suggest the fabrication of the composite could be improved in the future by controlling the manufacturing procedure.


2012 ◽  
Vol 84 ◽  
pp. 7-12 ◽  
Author(s):  
Tamiye Simone Goia ◽  
Kalan Bastos Violin ◽  
José Carlos Bressiani ◽  
Ana Helena de Almeida Bressiani

The porous metallic structure has been developed to mimic the natural bone architecture, having interconnected porosity, disposing enough room to cell migration, anchoring, vascularization, nourishing and proliferation of new bone tissue. The titanium is used as porous implants due its excellent mechanical properties and biological interaction. Research evolving porous titanium has been done with purpose to achieve desirable pore size, total porosity percentage and influence of those in the increasing of bone-implant bond strength interface. Were prepared samples of titanium by powder metallurgy adding natural polymer: corn starch, rice starch, potato starch and gelatin; at proportion of 16 wt%. In aqueous solution the hydrogenated metallic powder (TiH2) and the polymer were mixed, homogenized and frozen in molds near net shape. The water was removed in kiln (38°C/12h) and the polymer by thermal treatment with air-oxidation (350 °C/1h) before sintering in high-vacuum (1300 °C/1h). Resulting from the process, the obtained pores by addition of potato and corn starchs, lead to homogenous and well distributed throughout structure. Samples obtained from addition of rice starch and gelatin formed macropores and micropores randomly distributed within the structure. The apparent porosity for all samples was near 40%. The processing technique allowed the open pore formation, in which the macropores mimics the trabecular bone structure and micropores allows the bone-implant anchorage.


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.


2021 ◽  
Vol 23 (1) ◽  
pp. 178
Author(s):  
Anna Martina Tedeschi ◽  
Fabrizio Di Caprio ◽  
Antonella Piozzi ◽  
Francesca Pagnanelli ◽  
Iolanda Francolini

This study combines the use of corn starch and Tetradesmus obliquus microalgae for the production of antioxidant starch films as flexible packaging material. Starch was plasticized with glycerol and blended with 1 w% polyallylamine chosen as an agent to modify the film physical properties. The addition of polyallylamine improved film water stability and water vapor transmission rate as well as mechanical stiffness and tenacity. The dried Tetradesmus obliquus microalgae, which showed an EC50 value of 2.8 mg/mg DPPH (2.2-Diphenyl-1-picrylhydrazyl radical), was then used as antioxidant filler. The addition of microalgae provided the films with good antioxidant activity, which increased with microalgae content increasing. To our knowledge, this is the first study reporting the development of sustainable bioactive packaging films composed of almost 100% starch, and follows the European union’s goals on plastics strategy concerning the promotion of bio-based, compostable plastics and the setting up of approaches to prevent food waste with a simple plastic packaging.


2016 ◽  
Vol 30 (4) ◽  
pp. 564-577 ◽  
Author(s):  
Bin Guo ◽  
Li-Jian Wang ◽  
Peng Yin ◽  
Ben-Gang Li ◽  
Pan-Xin Li

The ultra-high molecular weight polyethylene (UHMWPE) fibers, as the fibrous morphology of polyethylene (PE), were first used to reinforce thermoplastic starch (TPS) by a twin screw extruder. The influence of the UHMWPE content on the mechanical and dynamic mechanical thermal properties, thermal stability, contact angle, torque rheological properties, and fractured surface morphology of the UHMWPE/TPS composites was studied in detail. We found that the UHMWPE fibers were well dispersed in the TPS matrix, and the mechanical properties and water resistance of the composites improved significantly. Especially, the incorporation of UHMWPE fibers at a content of 2 wt% generated a composite with better performance (tensile strength of 8.78 MPa and contact angle of 80.2°).


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.


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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