Starch-based Films Research Articles

Acetylated rice starch nanocrystals improved the physical, mechanical, and structural properties of native rice starch based films

Rice starch nanocrystals (SNC) and acetylated rice starch nanocrystals (ASNC) with three different substitution degrees (DS) for 0.22 (ASNCa), 0.56 (ASNCb), and 0.83 (ASNCc), respectively, were synthesized. Starch nanocrystals (SNC, ASNCa, ASNCb and ASNCc) with varying concentrations (0–25 %) were used in the production of composite rice starch-based films plasticized with glycerol using the solvent casting technique. Films were compared concerning their morphology, moisture content and solubility, transmittance, tensile strength, elongation at break. The SNC and ASNC content and acetylated DS had a significant effect (p ≤ 0.05) on all the properties investigated when compared to the control film. The addition of ASNC resulted in less hydrophilic films and UV light barrier properties, and the addition of SNC and ASNC increased the rigidity of starch film. There was an increase of 156.7 % in tensile strength for 10 % ASNCc composite films and a reduction of 68.1 % in water vapor permeability for 20 % ASNCc composite films. The rice starch/ASNCb nanocomposite films with the addition of 5 % and 10 % ASNCb exhibited a compact, smooth, and flat surface structure. Therefore, these results showed that ASNC significantly improved the mechanical properties, surface morphology and thermal stability of the films.

Development and characterization of pomegranate peel extract-functionalized jackfruit seed starch-based edible films and coatings for prolonging the shelf life of white grapes

In the current research, the pomegranate peel extract of varying concentrations (0.02, 0.04, 0.06, 0.08, and 0.1 g/mL) were incorporated into jackfruit seed starch (5 % w/w) based edible films and coatings for the evaluation their effects on the mechanical, physical, barrier and thermal properties. Furthermore, the effects of the optimized edible coating were investigated on the postharvest shelf life of white grapes at room storage (30 ± 5 °C, RH = 70 ± 5 %) conditions for up to 8 days. The obtained results showed a significant increment in thickness (p ≤ 0.05) with higher concentration (0.1 g/mL) of pomegranate peel extract (PPE), total phenolic content (959.33 ± 43.36 mg/100 g) and antioxidant activity (87.35 ± 1.64 %) of the prepared edible films but have negative impacts on the water vapor permeability (2.82 × 10−6 ± 6.48 × 10−7 g−1h−1pa−1) and oxygen permeability (1.62 × 10−14 ± 9.32 × 10−15 cm3·cm/cm2·s·cmHg), solubility (23.24 ± 3.21 %), and tensile strength (1.60 ± 0.43 MPa). The edible film enriched with 0.4 g/mL of PPE showed higher thermal stability in terms of glass transition temperature (98.2 ± 0.21 °C) and peak temperature (110.3 ± 0.35 °C). Additionally, the application of coating treatment significantly maintains the postharvest shelf life of white grapes throughout the storage period.

From micro to macro: Physical-chemical characterization of wheat starch-based films modified with PEG200, sodium citrate, or citric acid

Needing to extend the shelf-life of packaged food and the evolving consumer demands led researchers to seek innovative, eco-friendly, and biocompatible packaging solutions. Starch is among the most promising natural and renewable alternatives to non-degradable plastics. Here, we deeply study the structural features of starch films modified by adding citric acid (CA) or sodium citrate (SC) as a cross-linker and polyethylene glycol 200 (PEG200) as a plasticizer and obtained through solvent casting. The substances' influence on starch films was evaluated through Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) and Solid-state Nuclear Magnetic Resonance (ss-NMR) spectroscopies. Films' macroscopic properties, such as swelling index, solubility, thermo-mechanical features, and moisture absorption, were also assessed to foresee potential applications. Proper amounts of CA, CS, and PEG200 improve film properties and inhibit starch chains' retrogradation and recrystallization. Besides, the chemical neighbourhood of nuclei observed through ss-NMR significantly changed alongside the polymer chains' mobility. The latter result indicates a different polymer chain structural organization that could justify the film's higher resistance to thermal degradation and elongation at the break. This methodological approach is effective in predicting the macroscopic behaviour of a polymeric material and could be helpful for the application of such products in food preservation.

Synthesis of Biodegradable Polymer-Based on Starch for Packaging Films: A Review

Due to their crucial qualities and functionalities, polymers have received a lot of attention in recent years as food packaging materials. These characteristics include non-toxicity, ease of availability, biocompatibility, and biodegradability, showing their promise as an alternative to traditional plastic packaging, which has long been under investigation for its environmental impact. Given the present emphasis on sustainable development, research into biopolymers as eco-friendly and sustainable food packaging materials is critical. The synthesis of biodegradable polymers-based on starch represents a significant stride towards sustainable packaging solutions. As the global demand for eco-friendly materials continues to grow, ongoing research and innovation in this field are poised to lead to the development of starch-based packaging films with improved properties and widespread commercial applications. As a result, the primary goal of this review is to create a biodegradable polymer based on corn-starch and PVA with strong physicomechanical characteristics for usage in plastic bags.

Eggshell waste act as multifunctional fillers overcoming the restrictions of starch-based films

Starch has great potential to replace petroleum-based plastics in food packaging applications. However, starch films often exhibit poor mechanical and barrier properties, and are vulnerable to moisture and bacterial contamination. This study proved that the incorporation of eggshell powder (ES) enhanced the hydrogen bonding in starch-based films significantly, which contributed to improved tensile strength, Young's modulus, and water resistance of the films. The performance of ES-incorporated films could be optimized by adjusting the size, concentration, and surface property of ES in the film matrix. Notably, adsorbing epigallocatechin gallate (EGCG) on the surface of porous ES contributed to enhanced dispersibility of the fillers in the film matrix, which increased the tortuous path of light, water vapor, and oxygen have to take through the films, resulting in increased UV screening performance, water vapor and oxygen barrier property of the films by 60 %, 7.2 %, and 27.9 %, respectively. Meanwhile, loading EGCG in ES also enable superior antibacterial activity of the final films. This study suggests that eggshell fillers offer a sustainable means of improving the functional performance of starch-based films, which may increase their application as packaging materials in the food industry.

Dual-function β-cyclodextrin/starch-based intelligent film with reversible responsiveness and sustained bacteriostat-releasing for food preservation and monitoring

The full combination of high sensitivity indication and long-lasting bacteriostatic function is an innovative need to meet the practicality of intelligent film packaging systems for food products. Hence, Blueberry anthocyanins (BA) copigmentated by ferulic acid (FA) was used as an indicator, and cinnamon essential oil (CO) encapsulated by β-cyclodextrin (β-CD) as a bacteriostat, potato starch (PS) as a film-forming substrate to prepared a dual-function starch-based intelligent active packaging film with pH indicator and antibacterial function. FA had the best copigmentation effect with a threefold increase in a value compared to other phenolic acids. The ΔE value increased from 3.24 to 5.13 at pH 2–8, and the change was still prominent in acid-base alternating test, indicating a high response sensitivity. Notably, the yellow gamut of indicating terminus increased its visibility to the naked eye. The release behavior of CO from film was in line with Fick's diffusion. Meanwhile, the release of CO delayed to about 90 h through β-cyclodextrin encapsulation, showing a high growth-inhibition rate in E. coli and S. aureus of almost 100 %. In this study, a dual-function film with indication and bacteriostasis was prepared and enhanced with both, expanding its wide application in intelligent packaging of fresh food.

Modified lotus seed starch and red turnip peel extract based pH responsive edible films

Starch obtained from lotus seed was physically modified through heat-moisture treatment to develop the starch-based biopolymer films. Three different types of films: native lotus seed starch (NLS)- carboxymethyl cellulose (CMC), heat moisture treated modified starch (HMLS)-CMC, and modified starch incorporated with red turnip peel extract (HMLS-RTE)-CMC films were developed. The different filmogenic solutions exhibited non-Newtonian behavior with the shear thinning property and showed weak gel-like and viscoelastic behavior. The three different films' tensile strength ranged from 14.97 ± 0.65–21.13 ± 0.41 MPa and elongation at break ranged from 32.87 ± 1.14–44.31 ± 0.82%. The water vapor permeability in NLS was 3.86 × 10−7 gm−1h−1Pa−1 and in HMLS-RTE film, the WVP was decreased to 2.58 × 10−7 gm−1h−1Pa−1. The findings revealed that the pH-sensitive HMLS-RTE film had higher thermal stability, improved mechanical and moisture barrier properties than the NLS films, making them suitable for the intelligent food packaging system.

Contribution to the Study of the Water Behavior of Starch-Based Composite Films

Contribution to the Study of the Water Behavior of Starch-Based Composite Films

Influence of alkali treated cellulose nanoparticles filled starch-based bioplastic films and their effect on thermal and mechanical properties

In this study, structural, thermal, mechanical and water uptake properties on the influence of alkaline treated cellulose nanoparticles (CNPs) filled starch-based bioplastic film is examined. Starch-based bioplastic films filled with alkaline treated CNPs at various concentration (0 to 5 wt%) were prepared by solution casting method. Thermal properties of film series are examined by Differential Scanning Calorimetry (DSC) and Thermogravimetry analysis (TGA) method. Alkaline treated CNPs addition induces crystallization to the bioplastic film. Degradation onset temperature ( Don), 10% mass loss ( T10) and 50% mass loss ( T50) values show the positive effect of CNPs addition into the biopolymer matrix with improved thermal stability. Tensile result shows that about 2.5 times increased is observed in 2 wt% CNPs filled bioplastic films. Water uptake result shows that the alkaline treated CNPs starch-based bioplastic film limit the biopolymer dissolution time and extended the breaking down of the bioplastic film. Leading to about 2.5 times reduced equilibrium water mass uptake is observed in 3 wt% CNPs filled bioplastic film when compared with unfilled bioplastic film.

Study on hydroxypropyl corn starch/alkyl ketene dimer composite film with enhanced water resistance and mechanical properties

This study aimed to address the limited applicability of starch-based films in food packaging due to their inherent hydrophilicity, by developing a highly hydrophobic and mechanically reinforced film through compositing with alkyl ketene dimer (AKD). The FTIR analysis confirmed the successful introduction of AKD into the starch backbone via esterification by forming a β-keto ester linkage. Notably, the incorporation of AKD resulted in significant improvements in the modified film (S80A20), by exhibiting a higher water contact angle (WCA) of 128.28° and a reduced water vapor permeability (WVP) to 0.81×10-10 (g m/m2 s Pa). These enhancements were attributed to the inherent low surface energy of AKD and the increased surface roughness caused by AKD recrystallization. Moreover, the mechanical properties of the films were also enhanced due to the chemical crosslinking and intermolecular hydrogen bonding, as supported by the results of relaxation temperatures and molecular dynamics simulations. Considering the environmentally friendly and biodegradable nature of all components, the prepared hydrophobic films will hopefully be applied in food packaging.

Enhancement of the mechanical properties and water barrier properties of thermoplastic starch nanocomposite films by chitin nanofibers: Biodegradable coating for extending banana shelf life

Starch-based films have limited applications due to their hydrophilicity and poor mechanical performance. Herein, thermoplastic starch (TPS) nanocomposite films with chitin nanofibers (ChNFs) extracted from shrimp-shell waste were successfully fabricated using a solvent casting method. We investigated the effects of the ChNF loadings on the physical, mechanical, and water vapor barrier properties of the nanocomposite films. The well-dispersed ChNFs within the soft matrix associated with the formation of interfacial bonding between ChNFs and starch facilitated the efficient stress transfer from the soft matrix to the stiff ChNFs. Additionally, the presence of ChNFs created tortuous pathways within the films, which could impede the diffusion of water molecules. This resulted in a significant improvement in the mechanical properties, wettability, water resistance, and water vapor barrier properties of the nanocomposites. Compared to the results obtained from the neat TPS films, the TPS nanocomposites reinforced with ChNFs exhibited a 300% higher tensile stress, a 603% Young's modulus, and a considerable increase in the water contact angle, shifting from 86.2° to 98.6°. Furthermore, the ChNF-reinforced nanocomposite films showed no fragmentation after being soaked in water for 12 h under vigorous stirring, whereas the neat TPS films disintegrated under the same conditions. Interestingly, we found that coating a suspension of TPS and ChNFs on bananas effectively delayed their aging, preventing the color change from green to yellow. This promising result demonstrates the potential of the developed coating to extend the shelf life of fresh food produce, reducing food waste and the reliance on single-use petroleum-based packaging.

Effects of electron beam irradiation on ozone-modified potato starch film

Functional starch-based films are promising materials being developed at different laboratories. Native and modified starches are two materials being employed for this purpose. Chemical modification of starch generally involves esterification, etherification, or oxidation of the units that make up the starch polymers. Ozone constitutes an advanced oxidation technology for starch modification. In this work, properties of two kinds of materials - ozone-modified potato starch and irradiated ozone-modified potato starch-based films - were evaluated. Potato starch films were submitted to electron beam irradiation with doses up to 40 kGy. Films were produced by the casting technique using native and ozonated potato starch, glycerol as the plasticizer, and water as the solvent, and characterized in term of solubility and absorption of water, determination of oxygen gas transmission rate and Fourier Transform infrared Spectroscopy (FTIR) analysis. Ozone-modified potato starch presented strong alterations on pasting properties, with drastic reduction of viscosity values, water solubility and oxygen permeability. The data reported in this work contribute to the understanding of the ozone-modification process on starch and suggests further possibilities of industrial applications of ozonation on biomaterials.

Formulation and characterization of starch-based novel biodegradable edible films for food packaging

Petroleum-based plastics were widely used as packaging materials. However, plastic materials were not reusable and biodegradable, causing a severe negative impact on the environment. Edible films can be a suitable alternative to plastic films, particularly in food packaging. This research work prepared edible films containing blends of cornstarch, arrowroot powder, refined wheat flour, vinegar, and glycerol. Arrowroot powder added strength and nutritional value to the films. Glycerol, as a plasticiser, improved the flexibility of films. The combination of vinegar and glycerol increased the film’s strength. The characteristic properties of prepared films, like thickness, bursting strength, moisture content, transparency, water-solubility, water vapour permeability, tensile strength, elongation, and Young’s modulus, were analysed. The thermal stability of the films was evaluated by thermogravimetric analysis. The films were characterised by FTIR spectroscopy, and their surface morphology was analysed by scanning electron microscopy. The prepared films exhibited excellent properties suitable for food packaging.

Preparation and characterization of corn starch-based antimicrobial indicator films containing purple corncob anthocyanin and tangerine peel essential oil for monitoring pork freshness

A novel antibacterial indicator film was prepared by mixing corn starch with tangerine peel essential oil (TEO) Pickering emulsion emulsified by ultrasonic and esterified modified starch (UDSt), and then incorporated with purple corncob anthocyanin (PCA), which was used to monitor the freshness of pork. The results showed that the UDSt can effectively stabilize the TEO emulsion. PCA showed obvious color changes at different pH. With the increase of pH, the color of film changed from red to yellow, and its response to volatile ammonia changed from pink to cyan, showing better response ability. The loading of TEO conferred the film excellent bacteriostatic ability against E. coli and S. aureus. The film also had good ability of light blocking and free radical scavenging. In the process of pork deterioration, the antibacterial indicator film changed from pink to yellow, which was closely related to pork quality and had a good linear indicator correlation. The addition of TEO reduced the release of PCA in the antibacterial indicator film and helped to maintain the functional properties of the film. This type of antibacterial indicator film had considerable application potential in indicating food freshness.

Improved mechanical, functional and antimicrobial properties of corn starch-based biodegradable nanocomposites films reinforced with lemongrass oil nanoemulsion and starch nano-crystal

In recent times, negative influence of petroleum-based packaging materials on environment, sustainability and health has become a serious issue. Therefore, development of biodegradable packaging material for food related applications is rapidly gaining attention. The present study evaluates the influence corn starch nanocrystals (SNCs) (0.5%, 1% and 2%) in conjugation with lemongrass oil nanoemulsion (LNE) (2%) on the functionality of corn starch based film. The develop nanocomposite films were evaluated for their functional, tensile, barrier and functional properties and also characterized using X-ray diffraction (XRD), Nuclear Magnetic Resonance (NMR), Fourier transform infrared spectroscopy (FTIR) and Field-Emission Scanning Electron Microscopy (FE-SEM) techniques. Results revealed an increase in SNCs concentration caused a significant (p < 0.05) reduction in water barrier properties whereas incorporation of SNCs (≤1%) exhibited homogenous dispersion of nanocrystals into the matrix, improving tensile properties (15.53%). Opacity, color and crystallinity were influenced by the concentration of SNCs. SNCs/LNE loaded films exhibited increased opacity (↑63.1%) and antioxidant activity (↑348.2%). LNE induced small cavities on the film's surface, reducing the tensile strength and increasing elongation at break compared to SNCs loaded films. Antimicrobial activity of SNCs/LNE loaded films against E. coli. (ZOI-7.33 mm) and Staphylococcus aureus (ZOI-10.59 mm) was higher than SNCs-loaded films. SNCs and LNE, both reduced the degradation rate, yet films were completely degradable in soil, proving their potential utility in the development of functional and biodegradable food packaging.

Development, characterization and application of starch-based film containing polyphenols of piper betle L. waste in chicken meat storage

The current study aimed to develop a sustainable solution to extend the shelf life of chicken meat by developing starch-based functional film embedded with polyphenolic extract of waste petioles of betel leaf (BLP). The results showed that loading of the extract significantly (p < 0.05) improved flexibility, thickness, water solubility, DPPH radical scavenging activity, and UV light protection ability by enhancing intermolecular interactions among potato starch, guar gum, and the extract. The developed film showed optimum mechanical and water barrier properties at a 4% BLP extract concentration computed through TOPSIS method (A multi-criteria decision-making approach). During the shelf life study, the extract embedded film maintained the quality of chicken meat for up to 12 days at refrigerated temperature. Biodegradation time of the extract-blended films was considerably decreased to 14 days from 28 days for the native film, indicating suitable alternative to non-biodegradable film for storing the raw meat.

Preparation of starch nanoparticles by jet cavitation and enzymatic hydrolysis and their application in starch films

Potato starch was subjected to jet cavitation, freeze-thaw, ultrasound, acid, and enzymatic treatments to prepare starch nanoparticles. Enzymatic hydrolysis after jet cavitation pretreatment was found to be efficient. Therefore, enzymatic hydrolysis conditions of jet cavitation-treated starch were optimized. The smallest starch nanoparticles were obtained when the enzyme concentration was 66.68 nkat, starch concentration was 10 g/dL, and enzymatic hydrolysis duration was 3 h. The prepared starch nanoparticles showed a mixture of B and V-type crystalline structures with reduced relative crystallinity. A combination of potato starch nanoparticles and tea polyphenols was incorporated into potato starch-based edible films. The elongation at break of edible films significantly improved with the incorporation of starch nanoparticles. Additionally, the water resistance, tensile strength, and antioxidant activity of films improved with the addition of starch nanoparticles and tea polyphenols. Furthermore, the FTIR analysis indicated comparable spectra for all the starch-based films, except for the tea polyphenols-incorporated film, which exhibited a distinct band at 1605 cm−1.

Sustainable starch-based edible films with agrifood residues as potential carriers for the probiotic Lactobacillus rhamnosus

Edible films are promising carriers for probiotics and can be composed by agrifood residues, which are usually rich in polymers and bioactive compounds. In this work, starch-based films were enriched with three types of agrifood residues (quince, potato and orange peels) and the incorporation of the probiotic Lactobacillus rhamnosus was studied, as well as the addition of inulin as a protective prebiotic. The resulting films were characterized in terms of mechanical properties, physicochemical properties, lactobacilli viability and microbiological properties. The mechanical properties of the films generally decreased with the introduction of L. rhamnosus, although this was highly dependent on the film composition. All films exhibited water vapor permeabilities in the typical range of starch-based films and were not greatly affected by the inclusion of probiotics. The loss of probiotic viability during films production was strongly related to the pH of the film-forming solutions. Films with agrifood residues had a slower loss of probiotic viability during storage, when compared to plain starch films, which may be explained by the presence of antioxidant compounds. Inulin was expected to improve viability, but this was not observed. Microbiological analysis showed that agrifood residues powders contained natural contaminant bacteria that were partially eliminated during film formation. Moreover, none of the target foodborne pathogens were detected in the analyzed samples. Overall, the results suggest that edible films containing agrifood residues can be a promising material for the delivery of probiotics and/or as primary packaging for some food products.

Physicochemical properties of potato starch films containing natural extracts of turmeric and hibiscus

The development of biodegradable films is an alternative to the use of environmentally unfriendly packaging. For that, several natural polymers can be used, such as starch, which has good characteristics like inherent biocompatibility, biodegradability, and easy availability. The functional performance of starch-based biodegradable materials can be extended or improved by adding antioxidant agents, as well as by using novel preparation techniques. The addition of natural antioxidants to the starch-based films can further contribute to the development of functional films. The objective of the present work was to develop starch-based active films added with hibiscus and turmeric extracts. Important properties of the filmogenic hydrogels and the films prepared by casting such as absorption and solubility in water and oxygen permeability rate were determined. Oxidative degradation can affect the inherent color, flavor, and microbial stability of a variety of foods, then the oxygen transfer rate (OTR) was also determined. The information learnt from this study will be of value for further developments employing natural polymers or biocomposites being used as primary packaging for foods. Present tendency is to create active or smart packaging materials and starch-based materials that will play a significant role from now on.

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.