Modified Starch Films Research Articles

Valorization of guinea grass seed (Megathyrsus maximus): Synthesis and utilization of cellulose microfiber to reinforce esterified and cross-linked guinea starch films

The present study extracts starch from guinea grass seed and fiber from the starch extraction residue. The fibrous residue was chemically converted into cellulose microfiber (CMF) and used to reinforce the native, esterified and crosslinked guinea starch films. The films were developed with 5 % starch, 40 % glycerol and 0, 2.5, 5, and 10 % CMF based on the dry matter of starch. SEM images of all film samples showed good compatibility of CMF with starch molecules, and no fractures or pores were observed. Adding filler materials to modified starch films slightly increased the film thickness (0.24 to 0.30 mm) due to the high dimensions of CMF, which comprise a significant amount of the composite's volume. A synergetic effect of starch modification and CMF in films decreased the moisture content (21.98 to 9.21 %), water solubility (25.65 to 15.47 %), water vapor permeability (6.96×10−7 to 1.65×10−7g∙mm2∙day∙Pa), and elongation at the break (33.51 to 16.79 %) while increasing the tensile strength (1.84 to 3.85 MPa) and Young's modulus (5.49 to 22.93 MPa). The L* and a* values of the films decreased, and the b* and opacity values of the films increased with the addition of CMF. The XRD graph showed that all films have semicrystalline structures with peaks at 18°, 20°, and 22°, and the degree of crystallinity increases (32.3 to 55.1 %) with CMF. All film samples showed good thermal stability up to 315 °C. In conclusion, esterified starch-based films exhibited superior barrier properties and flexibility. On the contrary, cross-linked starch films demonstrated higher tensile strength and lower water solubility.

Improving water resistance and mechanical properties of starch-based films by incorporating microcrystalline cellulose in a dynamic network structure

The widespread use of starch-based films is hindered by inadequate tensile strength and high water sensitivity. To address these limitations, a novel starch film with a dynamic network structure was produced via the dehydration-condensation reaction of N, N′-methylene diacrylamide (MBA) and microcrystalline cellulose (MCC). The improvement in mechanical properties was enhanced by the incorporation of MCC, which was achieved through intermolecular hydrogen bonding and chemical crosslinking. To verify the interactions among MCC, MBA, and starch, x-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR), and x-ray diffraction (XRD) were conducted. The results established the predicted interactions. The dynamic network structure of the film reduced the water absorption capacity (WAC) of starch and MCC hydroxyl groups, as confirmed by differential scanning calorimeter (DSC) and dynamic mechanical thermal analysis (DMTA). These analyses showed a restriction in the mobility of starch chains, resulting in a higher glass transition temperature (Tg) of 69.26 °C. The modified starch films exhibited excellent potential for packaging applications, demonstrating a higher contact angle (CA) of 89.63°, the lowest WAC of 4.73 g/g, and the lowest water vapor transmission rate (WVTR) of 13.13 g/m2/d, along with improved mechanical properties and identical light transmittance compared to pure starch films.

TEMPO-oxidized cellulose nanofiber reinforced starch film with pH-responsive weakening and rapid marine-degradability

Self-standing films made of starch are a promising material for single-use packaging owing to their higher abundancy, degradability, and economical processability. However, weak mechanical strength and poor freshwater durability restricted their application. Our previous research demonstrated that blending TEMPO-oxidized cellulose nanofiber (TCNF) with modified starch enhances mechanical strength and freshwater durability through hemiacetal bonding. In this study, we demonstrated pH-responsive weakening in seawater and rapid marine-microbial degradability of TCNF reinforced modified starch films. The TCNF was blended with hydroxypropyl starch (HPS) and di-aldehyde starch (aldS) to develop the films. pH-responsive swelling and weakening were performed in freshwater and seawater with a variable pH from 4 to 9. Moreover, marine microbial degradability was evaluated in artificial marine environment. TCNF/modified starch film rapidly lost up to 80 % of its strength in seawater and has shown higher marine microbial growth and degradability compared to neat TCNF film. The TCNF/HPS film demonstrated the ideal behavior of both pH-responsive weakening with adequate microbial degradability. Therefore, it has the potential to become the next-generation packaging material to help address the problem of floating debris.

Modification and Characterization of Starch‐Based Food‐Packaging Material by Cold Plasma as a Green Approach

AbstractThis study focuses on the modification of starch using cold plasma (CP) for 0, 30, 60, and 90 seconds. The prepared films are characterized (i.e., thickness, water vapor permeability, intrinsic viscosity, solubility in water, and moisture absorption). The thickness, water vapor permeability (WVP), intrinsic viscosity, solubility in water (SW), moisture absorption (MA), and roughness of the modified starch films increases with longer plasma‐processing time (PPT). Conversely, the contact angle and density of the films decreases. However, there are no significant changes observed in the moisture content and UV–Vis spectrum of the cold plasma‐irradiated starch (CPS) films. The CP treatment has some effects on the mechanical properties of the films, such as elongation at break and tensile energy to break, but the tensile strength remains unaffected by PPT. Additionally, CP has a significant impact on the visual properties of CPS films, with increased lightness and white index with longer PPT. Most of the observed characteristics are attributed to physical changes in the starch structure caused by etching. Overall, CP is considered a green, and easy for modifying starch‐based packaging materials. However, it is not an effective method for reducing the sensitivity of the films to moisture at the applied PPT.

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, characterization, and antibacterial effect of bio-based modified starch films

There are several problems with common starch films, including strong water absorption and poor mechanical properties. To create a better starch film, octenyl succinate cassava starch ester (OSCS) was first blended with chitosan and nano ZnO to prepare an OSCS/CS/ZnO film. Then, the film was supplemented with different concentrations of ε-PL as a bacteriostatic agent to prepare a film that would resist bacterial invasion. The mechanical properties, barrier properties, optical properties, and color of the modified starch antibacterial films were investigated, and finally the antibacterial properties and cytotoxicity were tested. The results demonstrated that the modified starch antibacterial film had good mechanical properties, improved surface hydrophobicity, and had a UV-blocking effect. The modified starch antibacterial film with ε-PL of 8% had stable and long-lasting antibacterial properties, stable release, and good cytocompatibility. An active packaging material was successfully prepared using ε-PL and had a strong preservative effect on food.

Preparation of bio-based modified starch film and analysis of preservation mechanism for sweet cherry

This study aimed to synthesize packaging films using bioactive ingredients. The composite film was prepared by blending octenyl succinate cassava starch ester (OSCS) with chitosan (CS) nano-ZnO and then adding ε-polylysine (ε-PL). The study also explored the effect of different concentrations of ε-PL on OSCS/CS/ZnO films. Fourier infrared spectroscopyand fluorescence microscopy revealed that the composite film was formed by both hydrogen bonding and a Schiff base reaction. The diffraction peaks of the original materials in X-ray diffraction disappeared after film formation, indicating good miscibility between the materials. Scanning electron microscope showed that the density of its structure increased with increasing the ε-PL content. The thermogravimetric analysis showed that the addition of ε-PL improved the thermal stability of the composite film to some extent. When used in cherry preservation, the bio-based modified starch film effectively reduced cherry decay, stem dryness, and weight loss, maintained surface color, and increased the soluble solid content.

Ion-Modified Starch Film Enables Rapid Detection of Spoiled Fruit Juices

Juice, as a liquid foodstuff, is subject to spoilage and damage due to complications during transport and storage. The appearance of intact outer packaging often makes spoilage and damage difficult to detect. Therefore, it of particular importance to develop a fast, real-time material to evaluate liquid foodstuffs. In this paper, starch films with pH response characteristics are successfully prepared by inorganic ion modification by utilizing whole starch and amylopectin as raw materials. The mechanical properties, stability properties, hydrophilic properties and pH electrical signal response indices of the films are analyzed and measured. The films exhibit good electrical conductivity values with 1.0 mL of ion addition (10 mmol/L), causing the composite film to respond sensitively to solutions with varying pH values. In the test of spoiled orange juice, the full-component corn starch (CS) film has more sensitive resistance and current responses, which is more conducive for applications in the quality monitoring of juice. The results indicate that modified starch films can potentially be applied in the real-time monitoring of the safety of liquid foodstuffs.

Electrospinning of Microstructures Incorporated with Vitamin B9 for Food Application: Characteristics and Bioactivities.

The food industry has been expanding, and new vectors to entrap vitamins have been constantly investigated, aiming at versatile systems with good physico-chemical characteristics, low-cost production, high stability and the efficient release of active ingredients. The vitamin B9 (folic acid or folate) is essential for the healthy functioning of a variety of physiological processes in humans and is beneficial in preventing a range of disorders. In this study, two approaches were developed to encapsulate vitamin B9. Zein and the combination of modified starch with two plasticizers were the selected encapsulating agents to produce microstructures via the electrospinning technique. The objective was to improve the stability and the B9 antioxidant capacity in the final formulations. The work strategy was to avoid limitations such as low bioavailability, stability and thermosensitivity. The microstructures were fabricated and the morphology and shape were assessed by scanning electron microscopy. The B9 release profiles of modified starch and zein microstructures were analyzed in simulated gastric fluid at 37 °C, and in deionized water and ethanol at room temperature. The B9 encapsulation efficiency and the stability of the systems were also studied. The ABTS assay was assessed and the antioxidant activity of the produced microstructures was evaluated. The physico-chemical characterization of loaded B9 in the microstructures was achieved. High encapsulation efficiency values were achieved for the 1% B9 loaded in 12% w/w modified starch film; 5% B9 vitamin encapsulated by the 15% w/w modified starch with 4% w/w tween 80; and 4% w/w glycerol film with heterogeneous microstructures, 5% w/w zein compact film and 10% w/w zein film. In conclusion, the combinations of 7 wt.% of modified starch with 4 wt.% tween 80 and 4 wt.% glycerol; 15 wt.% of modified starch with 4 wt.% tween 80 and 4 wt.% glycerol; and 12 wt.% modified starch and 5 wt.% zein can be used as delivery structures in order to enhance the vitamin B9 antioxidant activity in the food and nutraceutical fields.

The Characteristics and Industrial Applications of Natural and Hydrophobic Modified Starch

AbstractThis study presents a product based on natural cassava starch with hydrophobic characteristics, which has been developed to replace the natural starch used in different industries. The natural and hydrophobic starch results describe their characteristics, validate the hydrophobicity through mathematical modeling, and present case studies from the paper and fruit processing industries that will be compared. The hydrophobicity and low viscosity of the modified Starch studied in this paper result from the reaction between hydrophobic radicals and the starch chain obtained from applying alkyl ketene dimer. A test for viscosity versus pH is also used to compare results for natural and modified starch, a kinetic model for water absorption is fitted to the hydration of samples of natural and modified starch, and the ability of a biofilm of modified starch to preserve fruit is also assessed. The degree of preservation of the fruit could be seen in the pictures that show that the fruit covered in the modified starch film has fewer alterations to its appearance after 64 days of observation. Moreover, the hydrophobic starch demonstrates superior results from the quality assessment when applied practically with paper and fruit, demonstrating their industrial potential.

Analyze Infrared Heating Characteristics of Potato Starch and Measure its Functional Film Properties

Objectives: To analyze the effect of potato starch infrared heating (IR) and the functional characteristics of the starch film. Methods: Potato starch was heated by IR heater at different time intervals (45 min, 65 min and 85 min) and starch was used to develop polymer films by the addition of glycerol as a plasticizing agent. The surface temperature of starch at different bed thickness was measured using a thermal imaging camera. The temperature of the starch varied from 72.77oC to 80.83oC. The functional properties of developed films were analyzed by their thickness, solubility, contact angle, puncture strength and coefficient of friction with different surfaces. Findings: The results indicate that the puncture strength of IR treated starch film varied from 2.5 to 3.79N and the value was found less in control recorded as 1.87N. The modified starch film thickness and opacity were increased from 0.11 to 0.128mm and 1.15 to 1.22 percent respectively. The solubility percent was found less in IR heated starch than in control. SEM and FTIR analysis results show that IR heat treatment has significant effect on morphology and functional characteristics of the starch film. Novelty: Infrared heating modified the structural characteristics of potato starch and improved the functional properties of the starch film. Keywords: Starch film; Infrared heating; Functional; Physical; Mechanical

Characterization and properties of singly and dually modified hydrogen peroxide oxidized and glutaraldehyde crosslinked biodegradable starch films

Poor properties of native cassava starch film such as low mechanical properties and high water uptake are the limitations of biodegradable starch films. Dual modification is an alternative way to improve the properties. Characteristics and properties of oxidized, crosslinked and dually modified starch films by hydrogen peroxide oxidation and glutaraldehyde crosslinking were examined. Sequence of the dual modification was also studied. All starch films were prepared by casting technique using glycerol plasticizer. The oxidation and crosslinking of modified starch were confirmed by carbonyl and carboxyl contents as well as degree of crosslinking. The lowest and highest molecular weights of the modified starch were observed for the oxidized starch and crosslinked starch, respectively. Moreover, swelling power and moisture absorption of dually modified starch films was clearly lower than those of singly modified films. Additionally, both good stiffness and extensibility was also obtained from the dually modified films especially for the crosslinked-oxidized film. Moreover, thermal property and biodegradability were also determined.

Synthesis and characterization of thermoplastic starch/PVA/cardanol oil composites loaded with in‐situ silver nanoparticles

AbstractA novel nanocomposite films of native and modified starch/polyvinyl alcohol (PVA)/sorbitol/cardanol oil with in situ synthesis of silver nanoparticles were prepared. The surface morphology of modified starch was found to be more homogenous than native starch with a good distribution of silver nanoparticles. This result indicated to boost in plasticization after starch modification as observed by scanning electron microscope. Transmission electron microscope confirms the formation of silver nanoparticles with diameters ranging from 50 to 80 nm with homogenously distributed. Moreover, modified starch showed lower water vapor permeability compared to unmodified starch at 39%. The addition of cardanol oil at 0.2% showed significant increases in the elongation of modified starch films by 280.9% compared to the unmodified starch films. However, the film elongation was increased by 421.7% with 2 mmol silver nanoparticles and 0.2% cardanol oil, while it decreased by 14.2 in the modified starch film. Also, cardanol oil reduces transmittance in the UV region for native and modified starch films by 56.2% and 56.5%, respectively. The nanocomposite films demonstrated good antimicrobial activity against gram‐positive and gram‐negative bacteria and yeast. These films can be a potential candidate for application such as food packaging materials.

Modification of banana starch (Musa paradisiaca L.) with polyethylene terephthalate: Virgin and bottle waste

Chemical modification of banana starch (Musa paradisiaca L.) with the degradation products of virgin and bottle waste of polyethylene terephthalate was carried out in situ. The modified starch was characterized by FTIR and NMR, which allowed proposing three chemical structures. SEM micrographs showed that the morphology of the modified starch granule is directly related with mass ratio of Starch/PET and type of PET used in the reaction. The crystallinity of the modified starch decreased up to 92.6% and 62.5% using bottle waste and virgin PET, respectively, according to XRD diffractograms. TGA analysis showed that the starch degradation temperature decreased by 12 °C. Modified starch films were elaborate and its electrical conductivity was found to be 2.9 times compared to that of native starch. The starch/PET film presented the highest value in the mechanical property of elongation at break compared to the starch-only film. The modified starch film was degraded above 80% by aqueous hydrolysis.

Study on enhanced mechanical, barrier and optical properties of chemically modified mango kernel starch films

The main aim of this study was to chemically modify mango kernel starch (MKS) and assess its impact on packaging film properties. MKS exhibited limited application due to low solubility, retrogradation, higher gelatinization temperature and hydrophilicity. These limitations could be effectually overcome by integrating modifications to native starch. Chemical modifications of MKS were performed by oxidation and benzylation with a low degree of substitution. X‐ray diffractogram presented A‐type pattern of crystal structure which was in accordance to endosperm starch. Fourier‐transform infrared (FTIR) spectra of the native and modified starch samples exhibited strong bands in the regions corresponding to OH and CH stretching. Additionally, absorption bands were found in the regions for carbonyl and aromatic phenyl vibrations signifying the substitution of functional groups within native starch. Modified starch films presented increased lightness L* representing that the films were lighter in colour than native film. Tensile strength (TS) of modified films was found to increase more than twice that of native starch film. Starch recrystallization was interrupted by oxidation thereby preventing retrogradation. Benzylation lowered the water vapour permeability by 58% and improved UV absorption by 80% when compared with native film.

Modified starch with bis(2-hydroxyethyl) terephthalate: synthesis, characterization and elaboration of films

Banana starch was modified with B bis(2-hydroxyethyl) terephthalate and its instrumental characterization allowed to propose a chemical structure. In the carbon 6 (C6) of the starch the modification reaction was carried out. The morphology of starch changes due to its chemical modification. The modified starch showed a lower crystallinity and thermal stability, compared to the native starch favoring its film formation. The electrical conductivity of the modified starch films was 2.7 times higher than that for the native starch film. The aqueous hydrolysis of the modified starch films was carried out obtaining a degradation of 77% in a determined time. Modified starch films present different mechanical properties compared to native starch film. These results have high application potential to be used in PET degradation products.

Synergistic effects of sodium adipate/triethylene glycol on the plasticization and retrogradation of corn starch

Starch retrogradation resulted in bad performance and taste of starch products. In this study, the corn starch films modified by sodium adipate and triethylene glycol were prepared by solution casting. The retrogradation of modified starch films were studied by FT-IR, XRD, SEM, tension test and UV–Vis. The results showed that sodium adipate was more effective than triethylene glycol in inhibiting the short-term retrogradation of starch, and triethylene glycol was more effective than sodium adipate in inhibiting the long-term retrogradation of starch. However, the mixture of sodium adipate and triethylene glycol, especially 15% adipic acid and 10% triethylene glycol, showed synergistic effects on the short-term and long-term retrogradation of starch. The starch film with 15% adipic acid and 10% triethylene glycol had the highest elongation at break, the best transmittance, the lowest change rate of elongation at break, and the lowest moisture content among all the recipes.

Production of biodegradable film based on sweet potato starch with hydroxypropylation-crosslinking

Plastics that are used as packaging have many advantages including flexible, transparent and not easily torn. The disadvantages of the material used in the manufacture of conventional plastics are non-biodegradable in the environment. One of the ingredients for making biodegradable films is white sweet potato, this is because chemically, sweet potato has amylose content of 35.99%. Native biodegradable starch films have hydrophilic properties, to overcome these weaknesses, it is necessary to repair or modify starch. Biodegradable hydroxypropylationcrosslinking films have a lower solubility value than unmodified films. High film solubility values indicate a decrease in the quality of the film to be used as food packaging material because the film easily dissolves in water and increases the possibility of damage to packaged products especially for products easily affected by water content. The tensile strength and percent elongation values of the entire modified starch films have a higher value than those of natural sweet potato starch films. Water vapor transmission rate (WVTR) is lower than that of natural sweet potato starch films. Transparency value has decreased to 13.89-14.10 (%abs/mm) which indicates that the film is in good clarity.

Effects of cross linking and/or acetylation on sorghum starch and film characteristics

In the present study, starch was modified by a) cross-linking through addition of 3% mixture of sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) based on starch weight b) acetylation through addition of 2%, 4% and 6% acetic anhydride based on starch weight c) dual modification i.e. cross-linking using 3% mixture of STMP and STPP followed by acetylation at 2%, 4% and 6% levels based on starch weight. These starches were then used to develop edible films followed by their characterization. Experimental results revealed that films with increased thickness were obtained from acetylated and cross linked starches whereas, dual modified starch films had reduced thickness compared to native starch film. Films from acetylated and dual modified starches retained more moisture compared to native and cross linked starch films while dual modified starches were more water soluble than acetylated and native starch films. All modified starch films were more clear and transparent compared to native starch films. Films from acetylated starches depicted lower tensile strength but they were more elastic and flexible than native and cross linked starch films. In contrast, dual modified starch films showed excellent mechanical properties and lower water permeability compared to native starch film.

Physical, Barrier, Mechanical, and Biodegradability Properties of Modified Starch Films with Nut By-Products Extracts.

Starch-based films with phenolic extracts could replace the use of petroleum-based plastics. In this study, octenyl succinate starch (OSS) films with pecan nutshell extract (PSE) or hazelnut skin extract (HSE) were prepared. The water resistance, as well as the optical, physical, mechanical, and biodegradable properties of these films, were investigated. The PSE and HSE improved the water resistance (decreasing the solubility to 17% and increasing the contact angle to 96.80°) and UV-light barrier properties of the films. For PSE and HSE, as their concentrations increased, the film rigidity decreased since these extracts acted as plasticizers. Micrographs obtained by scanning electron microscopy (SEM) depicted a homogeneous surface as a result of extracts dispersion through the polymeric matrix and the interactions between the phenolic compounds (PC) of the extracts and the OSS. The phenolic extracts from nut by-products and octenyl succinic anhydride (OSA) starch could be used to develop films to replace the conventional plastics.