Starch-based Biodegradable Films Research Articles

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.

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.

Synthesis of cellulose nano fiber from palmyrah fruit fiber and its applicability as a reinforcement agent on starch based biodegradable film

The global trend in packaging is shifting towards environmentally friendly, natural materials that decompose easily. Among the bio-based packaging materials, starch is a renewable, biodegradable, bio-compatible, and easily accessible source. However, starch-based biodegradable films depict weak mechanical properties compared with synthetic polymers. This problem can be solved by incorporating reinforcement fillers into the starch matrix. Palmyrah fruit (Borassus flabellifer L.) waste can be a good source to obtain fillers due to its high cellulose content. The aim of the study was to investigate the reinforcement of starch-based biodegradable films with the incorporation of pure cellulose nanofiber (CNF) obtained from palmyrah fruit fiber (PFF). Chemical treatments such as alkaline treatment (4% NaOH), bleaching [1% Ca(OCl)2], and acid hydrolysis (10 moldm-3 H2SO4) were done successively to obtain pure CNF from PFF. CNF was characterized using FTIR and particle size distribution (PSD) was analyzed by granulometry. The yield of CNF from PFF was 37.890±0.008 %. The results of FTIR depicted CNF was synthesized successfully. Five different biodegradable films were prepared by varying the amount of palmyrah tuber starch (4.5-2.5 w/w %) and CNF (0.0-2.0 w/w %) while the amount of glycerin (1.5 w/w %) and gelatin (1 w/w %) were kept constant. PSD results revealed that nano-sized CNF (10-100 nm) was synthesized successfully. The optimized film was selected based on the tensile strength and low water vapor transmission rate. Optimized film formulation, with palmyra tuber starch (3 w/w %) and CNF (1.5 w/w %) showed desirable physical, mechanical and optical properties, including the thickness, moisture content, water vapor transmission rate, water uptake, transparency at 600 nm, water activity, water solubility and tensile strength of 0.192±0.004 mm, 11.07±0.04 %, 3.870±0.005 g/m2.day, 22.34±0.05 %, 3.97±0.01 %, 0.440±0.001, 51.68±0.140 % and 9.55 MPa respectively. All films showed excellent soil biodegradability within two weeks. In conclusion, palmyra fruit CNF can be effectively used to reinforce starch-based biodegradable packaging films.

Starch-based biodegradable films amended with nano-starch and tannic acid-coated nano-starch exhibit enhanced mechanical and functional attributes with antimicrobial activity

Starch-based biofilms are biodegradable, but their application is limited by lower mechanical strength and absence of antimicrobial properties. In this context, the present study attempted to unleash the potential of nanotechnology for synthesizing nano-starch (NS) and tannic acid-coated nano-starch (T-NS) for augmenting the tensile strength and antimicrobial properties of starch-based biofilms. Moreover, this study reports one of the first such attempts to improve the commercial viability of starch extracted from the corms of Amorphophallus paeoniifolius. In this study, NS and T-NS samples were first synthesized by the physical and chemical modification of the native starch (S) molecules. The NS and T-NS samples showed significantly smaller granule size, lower moisture content, and swelling power. Further, amendments with NS and T-NS samples (25 % and 50 %) to the native starch molecules were performed to obtain biofilm samples. The NSB (NS amended) and T-NSB (T-NS amended) biofilms showed comparatively higher tensile strength than SB films (100 % starch-based). The T-NSB showed greater antimicrobial activity against gram-positive and gram-negative bacteria. All the biofilms showed almost complete biodegradation in soil (in 10 days). Therefore, it can be concluded that additives like NS and T-NS can improve starch-based biofilms' mechanical strength and antimicrobial properties with considerable biodegradability.

Optimizing the Functional Properties of Starch-Based Biodegradable Films.

A definitive screening design was used in order to evaluate the effects of starch, glycerol and montmorillonite (MMT) concentrations, as well as the drying temperature, drying tray type and starch species, on packaging film's functional properties. Optimization showed that in order to obtain films with the minimum possible thickness, the maximum elongation at break, the maximum tensile strength, as well as reduced water vapor permeability and low opacity, a combination of factors should be used as follows: 5.5% wt starch concentration, 30% wt glycerol concentration on a dry starch basis, 10.5% wt MMT concentration on a dry starch basis, 45 °C drying temperature, chickpea as the starch species and plexiglass as the drying tray type. Based on these results, starch films were prepared, and fresh minced meat was stored in them for 3 days. It was shown that the incorporation of MMT at 10.5% wt on a dry starch basis in the packaging films led to a decreased mesophilic and psychrotrophic bacteria growth factor compared to commercial packaging. When assessed for their biodegradability, the starch films disintegrated after 10 days of thermophilic incubation under simulated composting conditions. Finally, to prove their handling capability during industrial production, the starch films were rewound in a paper cylinder using an industrial-scale rewinding machine.

Effect of Crystallization Temperature on the Mechanical and Physical Properties of Solution Cast Polybutylene adipate co-terephthalate/Thermoplastic Starch Films

Starch-based biodegradable films of polybutylene adipate co-terephthalate (PBAT) have been prepared by the solution casting method. The effect of heating at two different temperatures (80 and 110°C) on the mechanical, optical and morphological properties of these films has been evaluated. The two temperatures were selected based on the crystallization and melting temperatures of PBAT. The blend of PBAT with thermoplastic starch has been prepared by melt mixing technique using two roll mills and then the solution casting method has been followed to prepare the films. Apart from curing at room temperature, the films have been cured at 80°C and 110°C. The tensile strength of the films increased by 110% and 252% for films heated to 80°C and 110°C, respectively. As revealed from spectroscopic analysis, the heating of films has no significant effect on the absorption of light by the films in the UV-visible region. The bonding characteristics of the films have been evaluated using Fourier transform infrared (FTIR) spectroscopy. The lowest water absorption and vapour permeability have been obtained in films cured at 80°C.

Properties Comparison of Oxidized and Heat Moisture Treated (HMT) Starch-Based Biodegradable Films.

Starch-based biodegradable films have been studied for a long time. To improve starch properties and to increase film characteristics, starch is commonly modified. Amongst different types of starch modifications, oxidation and heat moisture treatment are interesting to explore. Unfortunately, review on these modifications for film application is rarely found, although these starch modifications provide interesting results regarding the starch and film properties. This paper aims to discuss the progress of research on oxidized and heat moisture-treated-starch for edible film application. In general, both HMT and oxidation modification on starch lead to an increase in film's tensile strength and Young's modulus, suggesting an improvement in film mechanical properties. The elongation, however, tends to decrease in oxidized starch-based film, hence more brittle film. Meanwhile, HMT tends to result in a more ductile film. The drawback of HMT film is its lower transparency, while the opposite is observed in oxidized films. The observation on WVP (water vapor permeability) of HMT starch-based film shows that the trend of WVP is not consistent. Similarly, an inconsistent trend of WVP is also found in oxidized starch films. This suggests that the WVP parameter is very sensitive to intrinsic and extrinsic factors. Starch source and its concentration in film, film thickness, RH (relative humidity) of film storage, oxidation method and its severity, plasticizer type and its concentration in film, and crystallinity value may partly play roles in determining film properties.

Mechanical properties of tef starch based edible films: Development and process optimization

The non-biodegradable synthetic plastic is one of the greatest challenges facing the food packaging business since it seriously harms the environment. To solve this problem, non-biodegradable plastic may be disposed of more affordably and with less harm on the environment by using edible starch-based biodegradable film. Therefore, the present study was focused on the development and optimization of tef starch based edible films based on mechanical properties. In this study response surface methodology was employed by considering 3–5g of tef starch, 0.3–0.5% of agar and 0.3–0.5% of glycerol. The prepared film showed the tensile strength of 17.97–24.25 Mpa, elongation break of 1.21–2.03%, elastic modulus of 17.58–108.69 MPa, puncture force of 2.55–15.02 N, puncture formation of 9.59–14.95 mm. The findings showed that as glycerol concentrations in the film-forming solution increased, the prepared tef starch edible films' tensile strength, elastic modulus, and puncture force declined while their elongation at break and puncture deformation increased. Tef starch edible films' mechanical characteristics, including as tensile strength, elastic modulus, and puncture force, were increased by the increase of agar concentration. The optimized (from 5 gm tef starch, 0.4 g agar and 0.3% glycerol) tef starch edible film exhibited higher tensile strength, elastic modulus, and puncture force while lower elongation at break and puncture deformation. The composite edible film based tef starch with agar exhibited good mechanical properties and can be suggested for application in food industry as food packaging.

Adjusting hydrogen bond by Lever Principle to achieve high performance starch-based biodegradable films with low migration quantity

To adopt carbohydrate polymers as biodegradable plastic is a promising strategy to eliminate the pollution evoked by oil-based plastics. Thermoplastic starch (TPS) with different glycerol and tartaric acid (TA) contents were prepared by twin-screw extrusion, then extruded with poly (butyleneadipate-co-terephthalate) (PBAT) to obtain PBAT/TPS. A “Lever Principle” was adopted for adjusting the hydrogen bond strength of TPS by varying TA and glycerol contents which influenced the blocking force, mechanical properties and migration quantity of PBAT/TPS (PT) films manufactured by film blowing. Noteworthy, as the glycerol content decreased from 27.5 to 15 %, with 25 times “Lever Principle” for increasing TA content, the migration weight and blocking force decreased from 5.8 % and 58.4 × 10−4 N/mm for HPT0.5–27.5 to 1.7 % and 29.1 × 10−4 N/mm for HPT0.5–15 with 15.2 MPa tensile strength. This study adopted “Lever Principle” to adjust hydrogen bond strength, which could realize the good performance with low migration quantity for biodegradable PT films.

Isolation and characterization of lignin-rich particles as byproducts of bioethanol production from wheat straw to reinforce starch composite films

Bioethanol was produced from wheat straw by a concentrated alkali pretreatment at specific conditions with a yield of 88 g ethanol per 1 kg of dry straw. To economically improve the bioethanol production process and valorize residual waste, the lignin-rich solid waste particles were isolated from the pretreatment waste liquid and characterized, and finally employed to reinforce starch-based biodegradable film. The solid waste particles were characterized by chemical analysis, dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). As bioethanol byproducts, they have mainly contained 88 wt% lignin. The average diameter of the uniform spherical shape extracted particles was determined to be 160 nm by DLS and FESEM. The presence of syringyl and guaiacyl rings were conducted by FTIR. Due to their suitable mechanical performance and thermal resistance, the lignin nanoparticles were employed as reinforcement for green biodegradable starch films. To prepare films, suspensions containing starch, glycerol, and different concentrations of lignin (0–30 wt%) were molded by the solution casting process. The starch-lignin composite films were analyzed by mechanical tensile tests, crystallinity analysis, FESEM, and thermal analysis. From the results, it was found that by adding 20 wt% lignin particles, the tensile strength and modulus of the pure starch film were increased from 4.8 and 0.9–8 and 2.4 MPa which can be partially explained due to crystallinity enhancement of film from 29 % to 48.3 %. In addition, the thermal resistance and the hydrophilic property of the composite films were enhanced due to lignin nanoparticle presence. It can be concluded that the isolation of lignin nanoparticles as waste solid in bioethanol production could be considered as a promising stage in the sustainability of second-generation products from the bioethanol production process.

Effect on the Properties of Edible Starch-Based Films by the Incorporation of Additives: A Review.

At present, people more actively pursuing biodegradable-based food packaging to lower the environmental problems of plastic-based packaging. Starch could become a promising alternative to plastic because of its properties (easily available, nontoxic, tasteless, biodegradable, ecofriendly, and edible). This review article is focused mainly on the impact of the properties of starch-based biodegradable films, such as their thickness, morphology, and optical, water-barrier, mechanical, oxygen-barrier, antioxidant, and antimicrobial properties, after the incorporation of additives, and how such films fulfill the demands of the manufacturing of biodegradable and edible food-based film with preferable performance. The incorporation of additives in starch-based films is largely explained by its functioning as a filler, as shown via a reduction in water and oxygen permeability, increased thickness, and better mechanical properties. Additives also showed antimicrobial and antioxidant properties in the films/coatings, which would positively impact the shelf life of coated or wrapped food material.

Current Research and Applications of Starch-Based Biodegradable Films for Food Packaging.

The use of biodegradable packaging material as an alternative to conventional petrochemical-based polymers is based on the environmental issues associated with conventional materials. This review aims to update the existing knowledge regarding the application of starch-based biodegradable films for food packaging. From the review, it was evident that starch stands out among biopolymers due to its abundance and cost effectiveness. This review is the first of its kind, having reviewed over 100 articles/publications on starch-based biodegradable films, consolidating their current state of research and their applications for food packaging; therefore, this review provides an insight into the utilization of nanomaterials to improve the shelf life of packaging of food.

Sweet lime peel-, polyvinyl alcohol- and starch-based biodegradable film: preparation and characterization

Sweet lime peel-, polyvinyl alcohol- and starch-based biodegradable film: preparation and characterization

Effect of polymer blending on mechanical and barrier properties of starch-polyvinyl alcohol based biodegradable composite films

The study was aimed to improve the properties of starch-based biodegradable films by the way of polymer blending. The composite films were prepared by incorporating various proportions of PVA (10, 30, 50, 70, and 90% of starch wt.) to the starch using the solvent casting method. All films were analyzed for their mechanical behavior, barrier properties, water solubility, water contact angle, and biodegradability. Incorporation of PVA to starch polymer significantly (p < 0.05) improved the mechanical and barrier properties of composite films. The highest improvement in mechanical behavior was observed for the SP90 composite film, having a higher content of PVA. SP90 film showed 1.93 fold increase in TS, 3.74 fold increase in E and 1.72 fold increase in BS over the pure starch film. On the other hand, maximum PVA incorporation resulted in 52% and 57% decrease in WVP and OP of composite films respectively, depicting a good barrier against water vapour and oxygen gas. Fourier-transform infrared spectroscopy and scanning electron microscopy of films confirmed the excellent compatibility between starch and PVA polymer. Interestingly, the composite films degraded rapidly in moistened soil within 3 weeks of burial. Biodegradability study showed a promising potential of starch-PVA composite films for the development of eco-friendly food packaging material.

Starch-based biodegradable film with poly(butylene adipate-co-terephthalate): preparation, morphology, thermal and biodegradation properties

Starch was extracted from potato (Solanum tuberosum) cultivated in Nepal. The yield of starch of different sorts of the species S. tuberosum was compared with each other. Extracted starch (E St.) Kufre Sindure was characterized and compared with commercial starch (Com St.) by the Fourier transform infrared spectroscopy (FTIR). The properties of extracted starch were evaluated by measuring ash content, moisture content and amylose content. A series of butylene adipate-co-terephthalate (PBAT)/TPS blend of varying concentration (5%, 10%, 20% and 30%) were prepared using citric acid (compatibilizer) and glycerol as plasticizer, respectively, via solution casting method. The physical and chemical properties of resulting blends were characterized by FTIR and X-ray photoelectron spectroscopy (XPS). The FTIR results proved the esterification reaction between PBAT, thermoplastic starch (TPS) and citric acid in blends. Morphology of the PBAT/TPS film was studied through scanning electron microscopy (SEM) and XPS analysis. Microindentation measurements revealed improvement in mechanical properties of PBAT with the loading of starch. Thermogravimetric analysis (TGA) showed decrease in the thermal stability of PBAT/TPS blend. Degradation behavior of blend showed that rate of degradation was increased with increase of starch content.

Obtaining Starch-Based Biodegradable Film Materials for Prolonged Release of Biologically Active Compounds Using Wave Technology

This article proposes a wave technology for producing film composite materials based on native starch with Na-montmorillonite, which are intended for the prolonged release of biologically active compounds. It is shown that the use of wave effects at the stage of preparing a suspension for film composite materials promotes the formation of composites characterized by improved parameters of the kinetics of the release of biologically active compounds from films in comparison with those for the materials obtained using ultrasound.

Enhancement of water barrier properties of cassava starch-based biodegradable films using silica particles

Biodegradable films are used in a variety of applications, including packaging. However, their use is limited due to their high moisture and water sensitivity. In this work, cassava starch (CS) was blended with poly(vinyl alcohol) (PVA). Silica particles (SiO2) were incorporated to increase the hydrophobicity of the blend by intermolecular interaction through hydrogen bonding between the three components. Instead of a plasticizer or crosslinker, a small amount of triethylamine was added to eliminate residual acetate groups in PVA. The miscibility of CS and PVA phases was confirmed by smooth fracture surfaces and a single glass transition temperature. When SiO2 content was below 5% (wt), the particles were well dispersed in a continuous phase of polymer matrix. At this loading of SiO2, the increase in tensile strength was as high as 170% and in elongation-at-break, 250%. All loadings of SiO2 increased thermal stability of the blend films because silanol groups on the surface of SiO2 particles formed effective interfacial interactions with hydroxyl groups of the polymers. These interactions also prevented the ingress of water molecules, significantly increasing the hydrophobicity of the films. The water contact angle increased as high as 113° and moisture absorbency and water solubility were low. These highly hydrophobic, photodegradable, biodegradable CS/PVA/SiO2 films show great potential as a low-cost, eco-friendly material.

Preparation of Cassava Bagasse Starch-Based Biodegradable Film Reinforced with Chicken Feet Gelatin, Citric Acid as Crosslinker, and Glycerol as Plasticizer

Chicken feet is one of sources used to produce biodegradable films due to inexpensive and abundant source. Chicken feet contains extracted gelatin amount of 27.61 to 33%. This biofilm was prepared from cassava bagasse starch with citric acid as cross-linker and glycerol as plasticizer. Cassava bagasse contains about 40–64% of starch. This paper observes the optimum composition of cassava bagasse starch-based biofilm preparation upon Central Composite Design with variables of gelatin, glycerol, and citric acid concentration with response of tensile strength and elongation at break. This research was executed in several steps, i.e. extraction of gelatin, extraction of cassava bagasse starch, and casting. Optimum condition of this biofilm preparation can be obtained at 12.98% w of gelatin content, 0.22% w of glycerol and 0.27% w of citric acid by releasing 21.73 MPa of tensile strength and 19.73% of elongation at break. Mass loss of biofilm with lower gelatin content gave almost the same mass loss for blank biofilm (cassava bagasse starch-based without gelatin content). Increasing of gelatin content in the biofilm, increasing of the biofilm mass loss. However, the biofilm had good thermal stability by thermal gravimetric analysis with higher temperature to obtain inorganic residue than that of blank biofilm.

Physicochemical and Mechanical Characteristics of Potato Starch-Based Biodegradable Films

Physicochemical and Mechanical Characteristics of Potato Starch-Based Biodegradable Films

Preparation of Starch-Based Biodegradable Film and the Application in Agriculture

A starch-based biodegradable film was prepared in this paper, and the properties of the film were discussed. The film was prepared with polyethylene grafted and blended by epichlorohydrin modified-corn starch, linear low density polyethylene, low density polyethylene and maleic anhydride. Epoxy soybean oil was served as plasticizer and a small amout of ethylene propylene diene monomer was used as compatibilizer. 0.012 mm thickness degradable films were prepared with various blow molding methods. FTIR was used to characterize the modified starch and SEM was used to observe the morphology of the film before and after the modification. The results showed that the film could maintain an excellent performance on mechanical properties and degradation until the content of modified starch increased to 70% and have a good future in agricultural application.