Corn Starch-based Films Research Articles

Preparation and characterization of porous corn starch-based antibacterial sustained-release intelligent film

A novel porous corn starch-based antibacterial sustained-release intelligent film was prepared with the porous corn starch as the substrate, purple corn cob anthocyanin (PCA) as the indicator, and tangerine peel essential oil as the antibacterial agent, and its properties were studied. The results showed that the porous corn starch-based antimicrobial sustained-release indicator film had good mechanical strength, surface hydrophobicity and light transmittance. The tensile strength of the sustained-release indicator film (PLSt-12) prepared by porous corn starch with an enzymatic hydrolysis time of 12 h was 14.35 MPa and the elongation at break was 6.55 %. The water contact angle was 89.10°, and the water vapor transmittance was 6.62 × 10−4 g·mm2·s−1·Pa−1. The PLSt-12 was brown at pH 10 and had a sensitive color response. The PLSt-12 reduced the release rate of anthocyanins by 25.01 %, and the sustained-release mechanism was non-Fick diffusion. It showed a significant color change when the pork quality deteriorated, which can be used to monitor the freshness of the pork. This type of antibacterial sustained-release intelligent film had considerable application potential in indicating food freshness.

Use of Cold Plasma as an Alternative to Improve Corn Starch-Based Films: Effect of the Plasma Application Strategy

Starch-based biodegradable films are a type of packaging material that can naturally decompose in the environment. Current challenges regarding starch-based film applications are their high solubility and low hydrophobicity. Prior studies have shown that plasma application improves the physical, chemical, and mechanical properties of these films. This work evaluates the plasma application strategy regarding the process stage in which plasma should be applied (starch granule, film-forming solution, or film). Three groups of films were produced: a film produced with the plasma-treated starch, a film produced by subjecting the film-forming solution to plasma treatment, and a plasma-treated film produced with the untreated starch. A 22 face-centered experimental design was applied to each group of films to attain the optimal film of each group. The design consisted of applying plasma at 100, 200, and 300 Hz for 0, 10, and 20 min to each group. The results showed significant differences regarding their physical-chemical and morphological properties. Most chemical changes occurred in the starch subjected to plasma prior to film formation, while the films produced with the untreated starch presented physical changes. Plasma-treated films presented reduced solubility and higher hydrophobicity.

Investigation of film Physical properties under various starch thermal treatments with emphasis on Retrogradation effects

This study investigated the changes in the physical properties of cornstarch-based films as they were retrogradely aged at different temperatures. Using a casting method, the films were fabricated, and their effects on the mechanical properties, thermal stability, barrier properties, and essential properties were analyzed. With prolonged aging and retrogradation periods, reductions in film thickness, solubility, water content, and water vapor permeability of 5.35%, 9.92%, 29.61%, and 20.94%, respectively, were observed. In addition, the surface roughness decreased by 44.46% for Rq (root-mean-square roughness) and 45.61% for Ra (arithmetic average roughness), while the elongation at break decreased by 72.64%. Conversely, the tensile strength, maximum degradation rate, and maximum degradation temperature increased by 116.98%, 99.5%, and 3.21%, respectively. These results provide a fundamental understanding of the changes that occur in the properties of cornstarch-based films during aging and retrogradation.

Controlled release and antibacterial activity of corn starch-based films containing nanocellulose and thymol

The use of nanomaterials such as cellulose nanofiber (CNF) and antimicrobial compounds such as thymol (Thy), in starch films may improve the functional properties of films as active packaging films. This study quantifies the retention of thymol in corn starch (CS) and CS films containing cellulose nanofibers (CS/CNF) and investigates the migration of thymol from the films into a food simulant. A kinetic study was performed to evaluate the release of thymol from films into fatty acid food simulant (95% v/v ethanol) at 40 °C. The antibacterial activity of films was investigated via liquid culture assay. It was found that the addition of thymol significantly affects the surface morphology and cross-section of the films. CS/Thy and CS/CNF/Thy films retained thymol at 2.88 ± 0.50 and 11.21 ± 0.75 mg per g of CS/Thy and CS/CNF/Thy films, respectively. The release of thymol was affected by the presence of an intercalating network of CNF, which exhibited Fickian diffusion behavior. The release of thymol reached equilibrium within 48 h for CS/Thy, and 72 h for CS/CNF/Thy films. The CS/CNF/Thy film had a greater inhibitory effect than the CS/Thy film against Listeria monocytogenes and Salmonella Typhimurium. These findings demonstrate the potential applications of these films in improving the shelf life of perishable food products.

Effect of hydrophobic nano-silica content on the surface properties of corn-starch films

Starch-based films can be used for applications such as single-use packaging for food with a short shelf life. Hence, starch-based films could be a green alternative to some plastic packaging. This study analyzes the influence of hydrophobic silica content on mechanical properties, surface free energy, surface roughness, and morphology of corn starch-based films. For this purpose, commercially available amorphous hydrophobic nano-silica, Aerosil® R972, was used. The lowest value of surface free energy was observed for the starch films with the lowest glycerol and silica content (57 ± 1 mJ·m–2 for CG40S2.5), while the highest value was with the highest glycerol and silica content (73 ± 2 mJ·m–2 for CG80S5.0). The influence of silica content on the tensile strength decreases and elongation at break was investigated. The results showed that the surface roughness increases when the silica content increases. The SEM and EDS observation confirmed the homogeneity of the developed materials. This study shows that the commercially available Areosil® type of silica can be successfully used to change the performance of starch films.

Use of cellulose fiber from Jipijapa (Carludovicapalmata) as fillers in corn starch-based biocomposite film

Use of cellulose fiber from Jipijapa (Carludovicapalmata) as fillers in corn starch-based biocomposite film

Effects of different proportions of erythritol and mannitol on the physicochemical properties of corn starch films prepared via the flow elongation method

In this study, corn films based on corn starch were fabricated through the casting method, and various plasticizers (namely, erythritol and d-mannitol) were incorporated. The study delved into the gelatinization and physicochemical characteristics of these corn starch-based films. Additionally, the impact of different ratios of plasticizers on reductive gelatinization was assessed using RVA analysis. The investigation also encompassed the effects of varying plasticizer ratios on starch granule expansion, amylose dissolution, and amylopectin melting. Interestingly, as the proportion of d-mannitol increased, there were gradual increases in film thickness, water content, and water contact angle, alongside decreases in water vapor permeability, crystallinity, and water solubility of the corn starch-based films. In essence, this research provides a fundamental basis for potential industrial applications of corn starch-based films.

The Role of Virgin Coconut Oil in Corn Starch/NCC-Based Nanocomposite Film Matrix: Physical, Mechanical, and Water Vapor Transmission Characteristics.

Corn starch-based nanocomposite films usually have low moisture barrier properties. Adding virgin coconut oil (VCO) as a hydrophobic component can improve the nanocomposite film's characteristics, especially the film's permeability and elongation properties. This study aimed to determine the role of VCO with various concentrations (0, 3, 5 wt%) on the physical, mechanical, and water vapor transmission characteristics of corn starch/NCC-based nanocomposite films. Adding 3% VCO to the film showed the lowest WVTR value by 4.721 g/m2.h. At the same time, the value of tensile strength was 4.243 MPa, elongation 69.28%, modulus of elasticity 0.062 MPa, thickness 0.219 mm, lightness 98.77, and water solubility 40.51%. However, adding 5 wt% VCO to the film increased the film's elongation properties by 83.87%. The SEM test showed that adding VCO formed a finer structure with pores in several areas. The FTIR films showed that adding VCO caused a slightly higher absorption peak shift at the O-H groups and new absorption peaks at wave numbers 1741 cm-1 and 1742 cm-1. The results of this study may provide opportunities for the development of nanocomposite films as biodegradable packaging in the future.

Corn starch nanocomposite films reinforced with nanocellulose

Abstract The need for flexible food packaging has increased substantially in recent years around the world due to the unprecedented growth in food consumption. Due to low cost and ease of processing, petroleum-based synthetic polymer packaging materials are being predominantly used for food packaging these days. To avoid contributing to environmental problems caused by ecological risks, consumers have been searching for alternatives to plastic food packaging due to the fact that plastics cannot be recycled and are not biodegradable. Therefore, bioplastics made from corn starch, which are biodegradable, can be one solution to these issues. The starch’s amylopectin and amylase composition has a significant impact on the polysaccharide’s characteristics. Corn starch (CS) is utilized as a food source for humans and other animals, but it also has many other applications in industry. Corn starch, on the other hand, has a few issues that need to be addressed through some modifications. Although starch-based packaging is expensive, they create less waste overall, which helps in the reduction amount of plastic pollution. A variety of natural and synthetic polymers – including polysaccharide-based materials like Kappaphycus alvarezii seaweed, collagen, alginate, chitosan, zein, cellulose, gelatin, various amino acids and polymeric materials like acrylic acid, polybutylene (PB), polyacrylic acid, polyethylene (PE), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), and polycaprolactone (PCL) – are used as starch modifiers to produce polymers with a starch base that are completely biodegradable. These biopolymers have the potential to replacing petroleum-based polymers in a variety of commercial and industrial settings. Besides, corn starch nanocomposite films reinforced with nanocellulose have been investigated as a potential eco-friendly packaging material. Consequently, the effects of nanocellulose content on the mechanical, thermal, and barrier properties of corn starch-based films will be discussed in this work.

Starch-based environment friendly, edible and antimicrobial films reinforced with medicinal plants.

In the current study, cornstarch-based antimicrobial and edible films were designed using solution-casting methods. The medicinal plants (Acontium heterophyllum, Artemisia annua, and Thymus serpyllum) reinforced the gelatinized solution in different concentrations as fillers. The effect of plant extracts on antimicrobial and antioxidant potential, microstructure, barrier, thermal and mechanical properties of cornstarch-based films (SBFs) was investigated using antimicrobial activity, DPPH free radical scavenging values, scanning electron microscopy, X-ray diffraction, water vapor transmission rate, differential scanning calorimetry, and tensile strength. Likewise, it was depicted that the geometric and crystalline structures of medicinal plants' reinforced films remained the same even after processing. The mechanical tests indicated that the plant extracts effects are associated with reduced elongation, increasing tensile strength, and Young's modulus. Morphological analysis revealed the generation of uniform and the compact surfaces. However, films with 10% concentration of plant extracts have the lowest water vapor permeability values, and emerged better barrier properties. Moreover, these films showed the significant antioxidant potential and antimicrobial activity.

Correlation between chain structures of corn starch and properties of its film prepared at different degrees of disorganization

This study investigated the relationship between the chain structure of corn starch and the properties of corn starch-based films formed with starch pastes with different degrees of disorganization (70, 80, and 90 °C). The degree of gelatinization, chain length distribution, amylose content, and molecular weight of the corn starch were determined by the water absorption index, ion chromatography, spectrophotometry, and gel chromatography, respectively. The thickness, surface roughness, solubility, water content, water vapor permeability, mechanical properties, and maximum thermal degradation rate of corn starch-based films formed with starch pastes with different degrees of disorganization were evaluated. The moisture content, thickness and surface roughness of films formed with the starch pastes decreased. At the same time, the solubility, elongation at break, water vapor permeability, and molecular weight distribution increased with increasing heat treatment temperature. The maximum thermal degradation rate and tensile strength of the corn starch-based films formed with the starch pastes decreased with increasing heat treatment temperature. The gradual decrease in the amylose content of corn starch-based films formed with starch paste with increasing heat treatment temperature led to a change in the performance of the corn starch-based films.

Incorporation of Thymus vulgaris essential oil and ethanolic extract of propolis improved the antibacterial, barrier and mechanical properties of corn starch-based films

The present study illustrates the influence of Thymus vulgaris essential oils (TEOs), ethanolic extract of propolis (EEP), and their combination on corn starch-based films as antimicrobial packaging materials using the casting method. The FTIR results exhibited no structural change in the composite films after incorporating TEOs and EEP. However, the color properties of composite films were significantly affected by the addition of TEOs and EEP. The addition of TEOs and EEP increased the elongation at break from 5.8 to 13.5 % when TEOs and EEP added together, but tensile strength and modulus of the composite films decreased. The water solubility (SW) of composite films was significantly reduced when TEOs were added in the range of 17.31 % to 16.12 %. Also, the swelling ratio (SR) of all composite films was lower compared to the control film. The incorporation of EEP and TEOs did not change the water vapor permeability (WVP) of composite films significantly. However, the addition of EEP and TEOs in corn-starch films exhibited a synergic effect against Escherichia coli and Listeria monocytogenes. The developed antimicrobial composite films can be utilized in food packaging applications.

Effect of green coffee oil as a natural active emulsifying agent on the properties of corn starch-based films

Green coffee oil can be used as a biologically active emulsifier. In this study, corn starch-based composite films with different concentrations of Arabica coffee oil (ACO) and Robusta coffee oil (RCO) were prepared using the solution-casting method. The film-forming properties and physicochemical characteristics of the composite films were investigated, and their antibacterial activity was evaluated. With the addition of coffee oil, the mechanical properties of the corn starch-based films improved, and the thickness, UV light-shielding performance and transparency of the cornstarch-based film significantly increased. Compared with the oil-free or RCO addition films, the addition of ACO significantly reduced the solubility and water vapor transmission rate of the films, resulting in an improvement of waterproof performance of the films. Furthermore, adding of coffee oil formed micelles in the composite film, in which the active ingredient exhibited S. aureus inhibitory activity. The results showed that ACO, as bioactive vegetable oil, can be used as a natural surfactant to improve the overall performance of starch-based films. At the same time, ACO can meet the needs of consumers to reduce the use of chemical additives, and its application in corn starch-based composite films could become a promising food packaging platform.

Corn Starch-Based Bionanocomposite Film Reinforced With ZnO Nanoparticles and Different Types of Plasticizers

Corn starch var. Paragon from Indonesia and carboxymethyl cellulose (CMC) were used to develop bionanocomposite film containing different types of plasticizers [glycerol (G) or sorbitol (S)] incorporated with zinc oxide (ZnO) nanoparticles (NPs) (0, 3, 5 wt.%)viacasting method. The main objective of this study was to improve the properties of the bionanocomposite film with incorporated different types of plasticizers and ZnO NPs. The physicochemical properties of the film were systematically characterized. The results showed that the incorporation of sorbitol could significantly enhance the value of tensile strength, elongation, and Young's modulus than glycerol. In general, a higher concentration of ZnO NPs in the film could increase the tensile strength, reduce the water vapor permeability, decrease the water solubility, and influence the morphology, crystallinity, functional groups, and thermal stability of the films. The data showed that corn starch bionanocomposite film containing sorbitol with 5 wt% ZnO NPs was the most optimal film as compared to other formulations as the solubility and water vapor transmission rate (WVTR) value significantly reduced, and also it increased the value of tensile strength, elongation, and Young's modulus. It can be concluded that the incorporation of glycerol or sorbitol plasticizers reinforced by ZnO NPs plays an important role in improving the properties of bionanocomposite film, hence the film has the potency to be used as sustainable and environmental friendly packaging.

Nanocellulose reinforced corn starch-based biocomposite films: Composite optimization, characterization and storage studies

The nanocellulose (NC) synthesized from cotton linters was used as a reinforcement to develop biocomposite films with improved functionality. The starch films incorporated with varying percentages of NC and other additives (glycerol (GL), polyvinyl alcohol (PVOH)) were prepared using solvent casting method. Response Surface Methodology was employed to study and optimize the effect of film composition on tensile strength (TS), elongation at break (EB), bursting strength (BS), and water vapor permeability (WVP) of films. The optimum composite formulation obtained from the predictive model was: 0.89% NC, 2.53% GL, and 1.89% PVOH. The predicted responses in terms of TS, EB, BS and WVP were 8.92 MPa, 41.92%, 556 kPa, and 7.07 × 10−10 g/m.s.Pa respectively. The reinforcement of NC showed a significant (p < 0.05) improvement in mechanical and barrier properties of starch films. The films also presented high effectiveness in keeping the quality of edible oil for more than three months at ambient storage conditions. These bionanocomposite films have promising potential as an alternative packaging material for the storage of edible oils.

Effect of Different Ratios of Glycerol and Erythritol on Properties of Corn Starch-Based Films.

The demand for biodegradable products has increased; hence, a suitable method for producing green composites is essential. This study prepared corn starch-based films using the solution casting method, and the physicochemical properties of the prepared films were investigated using a mixture of glycerol (GLY) and erythritol (ERY) at different ratios (4:0, 3:1, 2:2, 1:3, and 0:4) as plasticizing agents. The crystallinity, hydrophilicity, mechanical properties, oxygen and water vapor, surface roughness, and thermal stability of corn starch-based films were analyzed using small-angle X-ray diffraction, water contact angle, automatic tensile testing machine, oxygen permeability tester and water vapor permeability analyzer, atomic force microscope, and thermogravimetric analyzer. With the increase in GLY ratio, the thickness, water-solubility, water content, water vapor permeability, elongation at break, oxygen permeability and V-shaped crystallization of the corn starch-based films increased. The tensile strength and the thermal stability decreased with increasing the GLY ratio. We developed a new plasticizer using glycerol and erythritol to improve the properties of starch films and provided the basis for the industrial production of corn starch-based films.

Effect of neem gum on water sorption, biodegradability and mechanical properties of thermoplastic corn starch-based packaging films

ABSTRACT Cornstarch (CS) is an inexpensive and widely available material that can be easily moulded into thermoplastic starch (TPS) films when mixed with the plasticising agent glycerol (CS- Gly). However, its applications in the packaging sector are limited due to its brittleness and high-water solubility. To enhance the functional characteristics of the CS- Gly films in packaging applications, it was blended with neem gum at the concentrations of 0.3 and 0.9% (w/w). The tensile strength, elongation percentage, water sorption and biodegradability efficacy of the blended cornstarch films (CS-Gly-NG) were analysed. The tensile strength of the blended film improved by 1.1-fold compared with CS-Gly (24.49 ± 0.72 MPa) when the natural gum additive was used at 0.30% (w/w). However, once the natural gum content was raised to 0.9% (w/w), the TS of the film decreased to 21.28 ± 1.75 MPa, whereas the resistance to water solubility improved to a greater extent. Moreover, the biodegradability test showed that the blended films (64-69 wt %) disintegrated more rapidly than the CS-Gly film (17.3%) in a setting akin to the natural environment. Therefore, this blended film (CS-Gly-NG) can be used as an alternative to the commercially available non-biodegradable polyethene films and will have a positive impact on the environment.

Improved properties of corn starch-based bio-nanocomposite film with different types of plasticizers reinforced by nanocrystalline cellulose

ABSTRACT A single-use of the corn starch-based bionanocomposite film has several weaknesses, such as stiffness, ease of brittleness, and low moisture barrier properties. The addition of plasticizers and nanocrystalline cellulose (NCC) is expected to increase packaging properties. This study used corn starch var. Paragon from Indonesia as a raw material to produce the strong film. The study aimed to evaluate the physical and mechanical properties of the bionanocomposite film based on corn starch with the addition of different plasticizers (glycerol (MW = 92.094 g/mol)/sorbitol (MW = (182.17 g/mol)) and different concentrations of NCC (0, 3, 5 wt.%). The result showed that the sorbitol plasticized film reinforced by 5 wt.% NCC was the most effective to improve the properties with the thickness 0.256 mm; the color values L*, a*, and b* 97.43, −0.04, 1.85, respectively; the water vapor transmission rate (WVTR) 2.259 g/m2 h; the water solubility 30.73%; tensile strength 4.69 MPa; elongation at break 56%; and young’s modulus 0.084 MPa. This treatment significantly reduced the film’s brittleness and water solubility while increasing its flexibility, tensile strength, elongation, young’s modulus, and resistance to water vapor transmission. Plasticizers more markedly affected the elongation properties of the films. However, NCC more significantly affected the tensile strength and WVTR films. In conclusion, this provides a great opportunity for the development of bionanocomposite films as biodegradable packaging in the future.

Preparation and characterization of biocomposite film derived from microcrystalline cellulose (MCC) of jackfruit rind waste

Biocomposite cornstarch films with various microcrystalline cellulose (MCC) derived from jack fruit rind (JR) had prepared via the solution casting method. This study aimed to investigate the effects of jackfruit rind microcrystalline cellulose (JR-MCC) composition on the properties of cornstarch biocomposite films. The FTIR analysis demonstrated that the addition of JR-MCC did not significantly change the chemical structure of the obtained composites. The mechanical test revealed that the tensile strength and Young’s Modulus decreased with increasing JR-MCC content while the value of elongation at break increased. As JR-MCC content increased from 2.5% to 15%, the water solubility decreased significantly from 21.80% to 12.73%. This phenomenon happened because JR-MCC reduced the water solubility of cornstarch-based films. JR-MCC was firm to dissolve in water and needed a longer time to dissolve. The moisture uptake and biodegradability of the films reinforced with JR-MCC also increased due to the sensitivity towards moisture.

Determination of the Tensile Properties and Biodegradability of Cornstarch-Based Biopolymers Plasticized with Sorbitol and Glycerol.

In this study, the effects of various quantities of sorbitol and glycerol plasticizers (0%, 30%, 45%, and 60%) on cornstarch-based film were examined to develop a novel polymer for usage with biodegradable materials. The film was prepared using the casting process. According to the test findings, the application of the plasticizer concentrations affected the thickness, moisture content, and water absorption of the film. When plasticizer concentrations were increased to 60%, the tensile stress and Young’s modulus of plasticized films dropped regardless of plasticizer type. However, the thin film with addition of 30% sorbitol plasticizer demonstrated a steady value of Young’s modulus (60.17 MPa) with an increase in tensile strength (13.61 MPa) of 46%, while the lowest combination of tensile strength and Young’s modulus is the film that was plasticized with 60% glycerol, with 2.33 MPa and 16.23 MPa, respectively. In summary, the properties and performance of cornstarch-based film were greatly influenced by plasticizer types and concentrations. The finest set of features in this research appeared in the film plasticized with 30% sorbitol, which achieved the best mechanical properties for food packaging applications.