Properties Of Starch-based Films Research Articles

Starch-based films with incorporated apple peel and chokeberry polyphenols

The aim was to prepare biodegradable starch-based films with active substances, and to examine the influence of temperature (80, 90, 99 °C), plasticizer (glycerol 1, 2, 4 %), and incorporation of phenolic compounds form apple peel and chokeberry on the properties of the films. The hygroscopic nature of glycerol affected the film properties. With the increase in glycerol content the water content, water solubility, and water vapor permeability of films significantly increased, while the swelling degree and hardness significantly decreased (p<0.05). Temperature did not have a significant influence on film properties. Phenolic compounds from apple peel and chokeberry increased the water solubility of films, and the loss of weight in water, in some cases significantly (p<0.05). The increase in hydrophilicity of films after the addition of phenolic compounds could be suggested, which affected the higher solubility and weight loss in the water. However, phenolic compounds decreased the swelling degree of films, in some cases significantly (p<0.05). The denser structure of films with the addition of phenolic compounds can be suggested, which caused the swelling degree to decrease. All films were biodegradable in water (the weight loss 18-38 %). The properties of starch-based films need to be studied and adjusted further for packing foods.

Characterizations of corn starch edible films reinforced with whey protein isolate fibrils

Starch-based films have been widely researched because of its degradability and low cost. The aim of this work was to evaluate the effect of the addition of protein fibrils, especially the content and the morphology of fibrils, on the properties of starch-based films. Corn starch/whey protein isolate fibrils (CS/WPIF) films were prepared using CS added with different WPIF contents (0.2%, 0.4% and 0.6%) at pH 2.0 or 7.0. The morphology of WPIF was adjusted via changing pH at 2.0 or 7.0, in which WPIF at pH 2.0 was longer than that at pH 7.0 as shown in transmission electron microscopy. The addition of WPIF at pH 2.0 or 7.0 increased the tensile strength, relative crystallinity, and storage modulus of CS films, and reduced the water content, total soluble matter content and water vapor permeability of the films. Compared with the short fibrils at pH 7.0, the long fibrils at pH 2.0 better improved the functional properties of CS films due to a strong network structure of long fibrils. CS/WPIF films with 0.4% WPIF exhibited the best properties, and WPIF at 0.6% reduced the film performance, which might be due to the aggregation of excessive WPIF. Also, CS/WPIF films showed superior antioxidant properties and inhibited the browning of fresh-cut apples during storage.

Enhancing the dispersibility of multiwalled carbon nanotubes within starch-based films by the use of ionic surfactants

The incorporation of carbon-based nanomaterials into biopolymer matrix, to provide mechanical reinforcement and to obtain electrically conductive bionanocomposites, requires the homogeneous dispersion of the fillers. Herein, it is investigated the influence of surfactant structures on the dispersibility of multiwalled carbon nanotubes (MWNT) within starch matrix. Three different ionic surfactants, sodium dodecyl sulphate (SDS), cetyltrimethylammonium bromide (CTAB) and sodium cholate (SC), are employed to disperse the MWNT. Films with MWNT-SC show better dispersibility and an increase of about 75% of tensile strength and 60% of Young's modulus compared with films using MWNT-SDS and MWNT-CTAB. Nevertheless, MWNT functionalized with CTAB impart the highest values of antioxidant activity (scavenging activity around 30% in 1.5 h) and electrical conductivity (σ =14.75 S/m) to starch matrix. The properties of starch-based films can be tailored according to the physical adsorption of each surfactant on MWNT surface and/or the interfacial interaction of the surfactant with starch chains.

Starch-based films: Major factors affecting their properties.

Starch is the most popular plant polysaccharides, which has been widely used for the development of edible coating films because of its abundance, cost-effectiveness, and excellent film-forming abilities. Starch-based films have good optical, organoleptic and gas barrier properties, however, they have poor mechanical properties. Many attempts have been made to overcome these limitations, such as the addition of co-biopolymers or other secondary additives to improve the mechanical and tensile properties of the films. Properties of the starch-based films can be influenced by many factors, including types of starches, temperature and time during film formation, plasticizers, co-biopolymers, and storage conditions. Understanding the mechanisms of these factors is very important for future studies on the development of starch-based films. This review focuses on starch as a film/coating material and comprehensively discusses the effects of major factors on properties of starch-based films.

Effect of natamycin on the physicochemical properties of corn starch based films and their effect on Penicillium spp. activity

The incorporation of antimicrobials in foods by means of the use of films where they are entrapped collaborates to decrease their diffusion rate. In this work, the physicochemical properties of starch-based films loaded with 1% wt. natamycin were analyzed, and the antifungal activity of these films was evaluated against Penicillium spp..Variations in the properties of films with 1% natamycin were minimal, leading to the conclusion that this material could be applied to avoid mold development on the surface semi-hard cheeses. Corn starch-based films containing natamycin at 1% w/w inhibited the Penicillium spp. growth in a solid matrix.

Effect of cellulose fiber from sago waste on properties of starch-based films

An increasing interest in developing biodegradable film using natural biopolymers such as polysaccharides is due to concerns on environmental problems caused by non-biodegradable petroleum-based materials. Though the film exhibits low mechanical properties, it can be improved by adding reinforcing agent, for instance, cellulose fiber. The objective of this study is to investigate the effect of adding cellulose fibers extracted from sago waste on the mechanical and thermal properties of sago starch-based films. Cellulose fibers extracted from sago waste showed reuction in size with cleaner surface as shown in FESEM micrographs. Thermal stability also improved indicated that the hemicelluloses and lignin were eliminated. Films were prepared by solution casting with 4 % sago starch and 3 % cellulose (from starch). These films were characterized using several techniques ie. tensile, x-ray diffractometry, TGA analysis, FESEM analysis and hazemeter. The films produced were highly transparent while film reinforced with cellulose fiber was more crystalline. The addition of fibers increased the tensile strength from 38.66 MPa to 40.70 MPa and Young’s Modulus from 1710 MPa to 1713 MPa. The elongation at break also increased from 3.85 % to 4.62 %. On the other hand, the incorporation of cellulose fibers increased the thermal stability of the film. FE-SEM micrographs of the films showed homogenous distribution of the cellulose fibers. The inclusion of cellulose fiber has successfully increased the properties of the sago starch-based film.

Preparation and properties of starch-based film using N,N-bis(2-hydroxyethyl)formamide as a new plasticizer

N,N-Bis(2-hydroxyethyl)formamide (BHF) was synthesized efficiently and used as a new plasticizer for corn starch to prepare flexible starch film. The hydrogen bond interaction between BHF and starch was proven by Fourier-transform infrared (FT-IR) spectroscopy. By scanning electron microscope (SEM), starch granules were completely disrupted and a continuous phase was obtained. The crystallinity of corn starch and BHF-plasticized starch film (BSF) was characterized by X-ray diffraction (XRD). The water resistance of BSF was better than that of glycerol-plasticized starch film (GSF). Water vapor permeability of BSF was lower than that of GSF. Tensile strengths of BSF were inferior to those of GSF, while the elongations at break of BSF were higher than those of GSF.

Preparation and Properties of Starch-Based Film Using N-(2-hydroxyethyl)formamide as a New Plasticizer

N-(2-hydroxyethyl)formamide (HF) was synthesized efficiently and used as a new plasticizer for corn starch to prepare flexible starch film. The hydrogen bond interaction between HF and starch was proved by Fourier-Transform Infrared (FT-IR). By scanning electron microscope (SEM), starch granules were completely disrupted, and the homogeneous materials were obtained. The crystallinity of corn starch and HF-plasticized starch film (HSF) was characterized by X-ray diffraction (XRD). Water vapor permeability of HSF was higher than that of glycerol-plasticized starch film (GSF). The elongations at break of HSF were higher than those of GSF at relative humidity 33%.

Characterization of the mechanical, chemical and thermal properties of antimicrobial (AM) starch-based films

The present study evaluated the mechanical, chemical and thermal properties of starch based film incorporating lauric acid and chitosan. Starch-based film incorporating chitosan and lauric acid as antimicrobial agents was prepared by casting method. Chitosan has widely been used in antimicrobial films, to provide edible protective coating, dipping and spraying for food products due to its antimicrobial properties and good mechanical properties. The starch-based films also have antimicrobial properties that can extend shelf-life of the packed food. The effect of addition of lauric acid and chitosan into starch-based films on mechanical, chemical and thermal properties were characterized by transperancy test, tensile test, scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC). The incorporation of chitosan and lauric acid into starch-based film enhanced the mechanical properties of starch-based films. Antimicrobial starch based film exhibited good flexibility. Tensile strength and percentage of elongation increased with the increasing chitosan content. SEM observations indicated that chitosan film was smooth and homogenous, while the starch film revealed characteristic granular pattern. The blend film exhibited an intermediate character with a slight microphase separation. Adding chitosan and lauric acid as antimicrobial agents in starch-based film indicated that there were interactions between the hydroxyl groups of starch and the amino groups of chitosan in the blend films as measured by FTIR.