Starch Films Research Articles

Physical and mechanical properties of starch films: the role of the cross-linking mechanism through iodine binding capacity

In this study, a better knowledge of the influence of cross-linking mechanism on the mechanical properties of starch films is presented. Thus, waxy starch and cassava starch films, cross-linked with trisodium trimetaphosphate (STMP), were produced and characterized concerning their morphology, transport, and mechanical properties. Starch cross-linking was verified by RAMAN spectroscopy and by iodine binding capacity (IBC) values, which were determined by color analysis of digital images. Although cross-linking affects the morphology and crystallinity of the films, it was not observed a relationship between the mechanism of the cross-linking reaction of the starch chain (amylose-amylopectin and amylopectin-amylopectin) and the transport properties. The lower Young Modulus and IBC value and the higher elongation at break observed for cross-linking cassava starch films relative to control and waxy films indicate that cross-linking mechanism influences the mechanical properties of starch films and should be considered to tailor the final properties of packaging and biobased products.

Biodegradability and biotoxicity of the modified starch matrix with biologically synthesized ZnO nanoparticles

AbstractIn the present study, the starch films with biosynthesized ZnO nanoparticles were obtained. The films obtained were examined for mechanical properties, environmental toxicity and biodegradation. It was observed that the addition of the ZnO nanoparticles to the polymer matrix caused an increase in the tensile strength and elongation at break. The STEZHP film was characterized by the elongation value at 306 (%). The addition of the nanoparticles had a positive influence on the degradation improvement of the films in question under the three different conditions applied. In turn, the presence of ZnONPs caused an increase in the toxicity of the materials investigated. In the case of the tests for toxicity towards plants, it was observed that the films (SAZ, SAZHP, SAEZ, and STZ) showed very little toxicity, as well as a weak correlation between the parameters of the film quantity and the shoot growth inhibition.

Preparation of nano-Ag-Bi2WO6–TiO2/starch bionanocomposite membranes and mechanism of enhancing visible light degradation of ethylene

Ag–Bi2WO6–TiO2 (ABT) ternary composite photocatalyst was prepared using solvothermal and surface deposition method. Then, the nano photocatalyst was doped into the starch film liquid through internal loading method, and finally, ABT/starch composite film was constructed using tape casting method for visible light catalytic degradation of ethylene. Characterize and analyze the structure and physical properties of nano ABT/starch composite membranes prepared with different ABT loading amounts, and optimize the reaction conditions (ABT addition amount, light intensity, initial concentration of ethylene) on the visible light catalytic degradation performance for ethylene of the composite membrane. The results show that the nano ABT particles and starch molecules have good biocompatibility, and they can be well fused to form a film, without changing the crystal structure of ABT and generating other chemical bond. The results of photocatalytic degradation of ethylene showed that when the loading amount of ABT was 5 wt%, the light intensity was 60.5 mw/cm2, and the initial concentration of ethylene was 0.15 mg/L, the ABT/starch film had the best ethylene degradation performance, with a K′ value of 5.6111 × 10−4 min−1, which is 17.9 times that of the blank starch film. Under the optimal preparation conditions, the thickness, tensile strength, elongation at break of the starch composite film is 168.33 μm, 5.01 Mpa, 32.4%, respectively, and the maximum thermal decomposition temperature is 320.5 °C, which meets the requirements for food packaging materials. After 4 cycles, the catalytic degradation of ethylene by starch composite membrane only decreased by 13.98%, indicating good reusability.

A Review on Reinforcements and Additives in Starch-Based Composites for Food Packaging.

The research of starch as a matrix material for manufacturing biodegradable films has been gaining popularity in recent years, indicating its potential and possible limitations. To compete with conventional petroleum-based plastics, an enhancement of their low resistance to water and limited mechanical properties is essential. This review aims to discuss the various types of nanofillers and additives that have been used in plasticized starch films including nanoclays (montmorillonite, halloysite, kaolinite, etc.), poly-saccharide nanofillers (cellulose, starch, chitin, and chitosan nanomaterials), metal oxides (titanium dioxide, zinc oxide, zirconium oxide, etc.), and essential oils (carvacrol, eugenol, cinnamic acid). These reinforcements are frequently used to enhance several physical characteristics including mechanical properties, thermal stability, moisture resistance, oxygen barrier capabilities, and biodegradation rate, providing antimicrobial and antioxidant properties. This paper will provide an overview of the development of starch-based nanocomposite films and coatings applied in food packaging systems through the application of reinforcements and additives.

Assessment of the enhancement potential of salicylic acid on physicochemical, mechanical, barrier, and biodegradability features of potato starch films

Filmogenic suspensions based on starch (S) and salicylic acid/starch (SA-S) were prepared and used to produce casted films (TPS and SA-TPS). An extensive characterization was conducted on both suspensions and casted films to assess their properties. Results evidenced that after storage for 120 days at 4 °C and 25 °C, the mold and yeast counts were significantly lower in the SA-S than in the S suspensions. Moreover, SA-S had a much lower initial viscosity than S. In reference to the films produced, salicylic acid caused a significant increase in film crystallinity, as well as a 2.3-fold increase in stress at break and a 3.8-fold increase in Young's modulus over the control films. Additionally, compared to TPS, the SA-TPS films exhibited a 46% decrease in water vapor permeability. All films showed a high biodegradation extent (≥85%) upon 75 days of home composting. These findings suggest that the salicylic acid addition at low concentrations (2 mM) can be a cost-effective approach for the development of highly stable starch filmogenic suspensions and also biobased films with distinguishing properties.

Functionality and characterization of modified starch films with pineapple leaf fibers

The objective of this work was to modify banana starch with pineapple leaf fibers (PALF) and its production of biodegradable films. The reaction conditions of the starch modification were a Starch/PALF mass ratio of 50, a time of 1 h and a temperature of 140 °C, to obtain a yield of 41.18 %. Characterization by FTIR and NMR confirmed that the chemical reaction was carried out. XRD and TGA analysis showed that the crystalline zones of the starch were affected during the modification and the product obtained is thermally less stable compared to unmodified starch. The modified starch showed a lower pasting profile compared to the native starch; however, the modified starch showed the ability to form a film. The starch-PALF films were obtained by the casting method and partially characterized. These films presented better mechanical properties compared to the unmodified films. Also, these films could compete with conventional non-biodegradable plastics.

Preparation and Application of Active Bionanocomposite Films Based on Sago Starch Reinforced with a Combination of TiO2 Nanoparticles and Penganum harmala Extract for Preserving Chicken Fillets.

The aim of this study was to develop sago starch-based bionanocomposite films containing TiO2 nanoparticles and Penganum harmala extract (PE) to increase the shelf life of chicken fillets. First, sago starch films containing different levels of TiO2 nanoparticles (1, 3, and 5%) and PE (5, 10, and 15%) were prepared. The barrier properties and antibacterial activity of the films against different bacteria strains were investigated. Then, the produced films were used for the chicken fillets packaging, and the physicochemical and antimicrobial properties of fillets were estimated during 12-day storage at 4 °C. The results showed that the addition of nano TiO2 and PE in the films increased the antibacterial activity against gram-positive (S. aureus) higher than gram-negative (E. coli) bacteria. The water vapor permeability of the films decreased from 2.9 to 1.26 (×10-11 g/m·s·Pa) by incorporating both PE and nano TiO2. Synergistic effects of PE and nano TiO2 significantly decreased the oxygen permeability of the sago starch films from 8.17 to 4.44 (cc.mil/m2·day). Application results of bionanocomposite films for chicken fillet storage at 4 °C for 12 days demonstrated that the films have great potential to increase the shelf life of fillets. The total volatile basic nitrogen (TVB-N) of chicken fillets increased from 7.34 to 35.28 after 12 days, whereas samples coated with bionanocomposite films increased from 7.34 to 16.4. For other physicochemical and microbiological properties of chicken fillets, similar improvement was observed during cold storage. It means that the bionanocomposite films could successfully improve the shelf life of the chicken fillets by at least eight days compared to the control sample.

Characterization of Laurus nobilis L. leaf essential oil incorporated maize starch and rice protein films

Characterization of Laurus nobilis L. leaf essential oil incorporated maize starch and rice protein films

The influence of the substitution degree and length of alkyl chains on the sizing properties of alkylation starches

In this work, a series of alkylation starches (St-C n) with different alkylation degrees was synthesized by introducing alkyl chains (the number of carbon atoms was 3, 8, and 12, respectively) onto starch. The influence of the substitution degree ( DS) and length of the alkyl chains on the sizing properties of alkylation starches was studied. Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectra provided evidence for the linkage of alkyl chains onto the starch structure. Benefiting from the flexibility characteristic of the alkyl chain and the weakening hydrogen bonding to starch structure, St-C8 alkylation starch film with a DS of 0.114 exhibited a high elongation break of 4.64%, which is higher than that of the modified starches reported in most of the literature. Moreover, the alkyl chain could reduce the internal stress of the starch adhesive layer among fibers, which improved the adhesion of alkylation starch to cotton fibers. The St-C12 alkylation starch obtained by the longer alkyl chain weakened the adhesion among fibers due to the strong hydrophobic effect. This work provides a new idea to achieve starch plasticization.

Polymer-Based Long-Lived Phosphorescence Materials over a Broad Temperature Based on Coumarin Derivatives as Information Anti-Counterfeiting.

The development of new polymer-based room-temperature phosphorescence materials is of great significance. By a special molecule design and a set of feasible property-enhancing strategies, coumarin derivatives (CMDs, Ma-Mf) were doped into polyvinyl alcohol (PVA), polyacrylamide (PAM), corn starch, and polyacrylonitrile (PAN) as information anti-counterfeiting. CMDs-doped PVA and CMDs-doped corn starch films showed long-lived phosphorescence emissions up to 1246 ms (Ma-PVA) and 697 ms (Ma-corn starch), reaching over 10 s afterglow under naked eye observation under ambient conditions. Significantly, CMDs-doped PAM films can display long-lived phosphorescence emissions in a wide temperature range (100-430 K). For example, the Me-PAM film has a phosphorescence lifetime of 16 ms at 430 K. The use of PAM with the strong polarity and rigidity has expanded the temperature range of long-life polymer-based phosphorescent materials. The present long-lived phosphorescent systems provide the possibility for developing new polymer-based organic afterglow materials with robust phosphorescence.

Effect of montmorillonite and starch nanocrystals based biodegradable films loaded with lemongrass oil nanoemulsion on quality, enzymatic activity and shelf life of strawberry

The present study aims to determine the influence of montmorillonite (1.5% w/v MMT) and starch nanocrystals (1% w/v SNCs) based corn starch films loaded with lemongrass oil nanoemulsion (2% v/v LNE) on the shelf life and quality characteristics of strawberries (variety Tioga) stored at 4ºC for 8d. Results revealed that MMT and SNCs reinforcement enhanced tensile properties while reducing the WVTR of the films. Active nanocomposites provided superior shelf stability whereas control (unpackaged strawberry) demonstrated the highest quality deterioration in strawberries throughout storage. Amongst nanocomposites utilized, MMT/LNE based films exhibited the best preservative effects on the quality of strawberries, owing to their better barrier properties than SNCs/LNE. On the 8th day, MMT/LNE based films demonstrated highest retention of the physicochemical properties, phenolic content (69.50%), anthocyanin content (86.76%) and DPPH scavenging activity (67.60%). The activity of antioxidant enzymes (superoxide and catalase) was also preserved best with the MMT/LNE based films. Active nanocomposites reduced microbial growth with MMT/LNE films showing the least microbial progression. MMT/LNE and SNC/LNE loaded nanocomposites increased the strawberries’ shelf life up to 8 and 6 days, respectively in comparison to the control (4 days), illustrating the effectiveness of nanocomposites in maintaining postharvest quality of strawberries.

A composite starch-date seeds extract based biodegradable film for food packaging application

The current work focuses on the preparation of biodegradable films from natural polymer such as starch modified by cellulose and chitin with incorporation of extracts from date seeds for probable application as food packaging materials. Date seeds which are widely available in the United Arab Emirates (UAE) were used to obtain extracts which are very rich in phenolic compounds. Composite starch films were prepared and analysed for their physical and chemical properties. It was observed that tensile strength of the composite films increased to 16 MPa when compared to the non-composite films. Biodegradability study was carried out by replicating ASTM D5988 which included soil burial of the prepared films at optimal moisture conditions (60–65%) and temperature (25–30 °C). The test suggested that the films could be easily degraded in composting soil by 5–7 weeks. Addition of extracts from date seeds to the prepared composite film imparted antioxidant and antimicrobial properties, which when used for fruit wrapping suggested that the freshness of the fruit was retained for a much longer period. Detailed analysis on economic aspects of the film production suggested the feasibility of the prepared films in term of cost.

Antifungal and ultraviolet–visible barrier properties in starch films reinforced with CuO nanoparticles

AbstractStarch materials are subject to loss of initial characteristics due to the retrogradation degenerative effect, high hygroscopicity, and favoring the growth of the microorganisms, which reduces the shelf life of packaging. In this sense, the insertion of nanoparticulated CuO was evaluated for the best performance. CuO is a semiconductor that can improve optical, mechanical, and antimicrobial properties, enabling excellent promotion of starch films. The hot injection precipitation method was used to obtain CuO nanoparticles in the nanometric scale rapidly. The films were carried out from the starch homogenization in water and urea under temperature, followed by thermopressing at 120°C. As a result, the 1% CuO (w w−1) increased tensile strength from 0.87 ± 0.40 to 1.92 ± 0.09 MPa. Furthermore, the films containing nanoparticles showed a barrier property against radiation in the ultraviolet–visible spectrum, not observed for the micrometric scale. Such results were attributed to the superior opacity of the films generated by nanometric reinforcement. Concerning antimicrobial activity, the films containing CuO showed a fungistatic effect (33%) for the Alternaria alternata fungus, a microorganism very susceptible to carbohydrate‐rich sources. Thus, the CuO‐reinforced starch films improved physicochemical and biological properties, making them promissory candidates for commercial application.

Novel Biodegradable Composite Mulch Film Embedded with Temperature-Responsive Pesticide Microcapsules for Durable Control of Phytophthora Root Rot on Soybean

Soil-borne diseases have caused substantial economic losses to agricultural production due to their rapid onset and few means of control. Here, pyraclostrobin (Pyr) microcapsules (Pyr@MCC) with temperature-responsive pesticide release capability were prepared using temperature-sensitive phase-change materials as capsule cores. Then, the Pyr@MCC was organically combined with poly(vinyl alcohol)-starch film (PVA/ST) to prepare a composite mulch film (PM/PVA/ST) with intelligent control of pesticide release rate according to external temperature change, which realized sustainable and efficient control of Phytophthora root rot (PRR) on soybean. Tensile tests showed that the PM/PVA/ST film exhibited good tensile deformation ability (134.9%) and high tensile stress (18.0 Mpa). The water vapor transmission rate test showed that the PM/PVA/ST film exhibited good barrier performance to H2O, CO2, and O2. The release test data proved that the PM/PVA/ST film could slowly release Pyr at lower temperatures (15 °C) and release Pyr rapidly at higher temperatures (35 °C), corresponding to the high temperature at which the Phytophthora root rot outbreak. In vitro antifungal and pot experiments showed that the PM/PVA/ST film had a good control efficiency on Fusarium spp. These results show that the functional pesticide microcapsules loaded onto the film have good application potential for controlling PRR on soybean. In general, this composite mulch film provided some innovative research ideas for optimizing the pesticide delivery pathway and thereby efficiently controlling soil-borne pests and diseases, reducing the frequency and amount of pesticide use and minimizing white pollution from traditional plastic mulch films.

Properties of agar/cassava starch films manufactured by hot-melt extrusion method

Agar/cassava starch bioplastic film preparation using the extrusion technique was carried out to obtain a continuous production method that is more applicable to industrial production practices. Various ratios (w/w) of agar-and-cassava-starch blends were used in the bioplastic film formulations with glycerol as the plasticizer. All the ingredients were compounded using a single-screw extruder at 110°C. The extrudates were dried and chopped into bioplastic resin pellets, followed by hot compression into a film sheet. The bioplastic film samples were tested for their mechanical properties, water sensitivity, biodegradability and chemical structures. In general, the amount of agar in film formulations was prominently associated with superior mechanical properties, such as the tensile strength, elongation at break and water resistance of the samples. On the other hand, cassava starch contributed to faster film degradation in soil and water. These results, in general, could be explained by the inherent properties of each biopolymer constituent and the number of hydroxyl groups (OH) in the chemical structure of each film sample, which was observed by Fourier transform infrared spectroscopy. This investigation showed that agar/cassava starch bioplastic production using the hot-melt extrusion method was promising for further implementation on a commercial production scale.

Cover Image

The cover image is based on the Research Article Improvement of the UV‐resistance capability of fish gelatin‐oxidized starch film via inserting mycosporine‐like amino acids by Donghui Wang et al., https://doi.org/10.1002/jsfa.12587. image

Biobased ternary films of thermoplastic starch, bacterial nanocellulose and gallic acid for active food packaging

The use of active packaging technologies and biopolymeric materials are among the emerging trends for implementation of sustainability in the food packaging industry. Thus, herein, bioactive transparent nanocomposite films of thermoplastic starch (TPS) reinforced with bacterial nanocellulose (BNC) (1%, 5% and 10% w/w, relative to starch) and enriched with gallic acid (GA) (1 and 1.5% w/w, relative to starch) were prepared by the solvent casting method. The addition of BNC (≥5% w/w) and GA (1 and 1.5% w/w) enhanced both the mechanical properties (Young's Modulus: 1.2–2.0 GPa vs. 1.0 GPa for TPS; tensile strength: 23–39 MPa vs. 20 MPa for TPS) and the water resistance (moisture absorption and solubility in water) of the nanocomposites. All films are thermally stable up to 125 °C. It was also found that the addition of GA imparted the hydrocolloid TPS-BNC nanocomposites with UV-blocking properties and antioxidant activity (DPPH scavenging activity above 80%). In addition, the film with 10% w/w of BNC nanofibers and 1% w/w of GA had good oxygen barrier properties with a coefficient of permeability of 0.91 ± 0.12 cm3 μm m−2 d−1 kPa−1 and antibacterial activity against the gram-positive Staphylococcus aureus (reduction of about 4.5 log10 colony forming units (CFU) mL−1 after 48 h). This is the first time that antibacterial activity is reported for TPS-BNC nanocomposites. The film with 10% w/w of BNC nanofibers and 1% w/w of GA was further demonstrated to have the ability of delaying the browning and weight loss of packaged fresh cut apple stored at +4 °C for 7 days. All these outcomes are of great relevance for the packaging sector, thus attesting the potential of the developed TPS-BNC-GA nanocomposites as sustainable and eco-friendly film materials for active food packaging.

Addition of cinnamon extract in making edible film of sago starch as packaging for lempok durian

The purpose of this study was to obtain the best concentration of cinnamon extract in making edible film of sago starch as lempok durian packaging. This research was conducted experimentally using a completely randomized design (CRD), four treatments, and four replications to obtain 16 experimental units. The treatments used were the concentration of cinnamon extract with P1 (without cinnamon extract), P2 (cinnamon extract 3%), P3 (cinnamon extract 5%), and P4 (cinnamon extract 7%). Observations were made on edible film moisture content and water vapor transmission rate. Observations made on lempok durian that had been coated with edible film with cinnamon extract were free fatty acids, descriptive aroma test, and texture. The data obtained were analyzed statistically with the Analysis Of Variance (ANOVA) test using IBM SPSS Statistics 24 software. If Fcount ≥ Ftable, then continued with Duncan’s New Multiple Range Test (DNMRT) at 5% level. The best treatment in this study was P4 (addition of 7% cinnamon extract) with the criteria of edible film water content 11.87%, water vapor transmission 7.54%. Criteria of lempok durian day 9 free fatty acids 1.55%, aroma descriptive test 1.90 (slightly rancid), and texture descriptive test 1.85 (slightly chewy). The advantage of this research is that the addition of cinnamon extract can extend the shelf life of lempok durian.

Toward a Circular Bioeconomy: Exploring Pineapple Stem Starch Film as Protective Coating for Fruits and Vegetables.

In order to reduce our dependence on nonrenewable plastics and solve the problem of non-biodegradable plastic waste, there has been much attention paid to the development of biodegradable plastics from natural resources. Starch-based materials have been widely studied and developed for commercial production, primarily from corn and tapioca. However, the use of these starches could generate food security problems. Therefore, the use of alternative starch sources, such as agricultural waste, would be of great interest. In this work, we investigated the properties of films prepared from pineapple stem starch, which has a high amylose content. Pineapple stem starch (PSS) films and glycerol-plasticized PSS films were prepared and characterized using X-ray diffraction and water contact angle measurements. All films exhibited some degree of crystallinity, making them water-resistant. The effect of glycerol content on mechanical properties and gas (oxygen, carbon dioxide and water vapor) transmission rates was also studied. The tensile modulus and tensile strength of the films decreased with increasing glycerol content, while gas transmission rates increased. Preliminary studies showed that coatings made from PSS films could slow down the ripening process of bananas and extend their shelf life.

Development of intelligent and active potato starch films based on purple corn cob extract and molle essential oil

The present study aims to develop an active and “intelligent” film that uses potato starch as a polymeric matrix, anthocyanins from purple corn cob as a natural dye, and molle essential oil as an antibacterial compound. The color of anthocyanin solutions is pH-dependent, and the developed films show a visual color change from red to brown after immersion in solutions with pH values ranging from 2 to 12. SEM and FTIR analyses suggested that anthocyanins have favorable dispersibility and good compatibility with the starch-glycerol matrix. The study found that both anthocyanins and molle essential oil significantly enhanced the ultraviolet-visible light barrier performance. Tensile strength, elongation at break, and elastic modulus reached values of 3.21 MPa, 62.16 %, and 12.87 MPa, respectively. The biodegradation rate in vegetal compost also accelerated during the three-week period, achieving a weight loss of 95 %. Moreover, the film presented an inhibition halo for Escherichia coli, indicating its antibacterial activity. The results suggest that the developed film has the potential to be used as food-packaging material.