Effect of kaolin impregnated with calico plant extract on properties of starch films.

Starch film has poor tensile properties and poor water resistance. We aimed to improve these properties by adding kaolin impregnated with calico plant extract (CP-Kaolin). UV-Vis spectrophotometry showed that the calico plant extract (CPE) contained 4867.52 mg/L of total phenolic compounds and betacyanins were the predominant constituents. CP-Kaolin was characterized by Fourier transform infrared spectroscopy (FTIR), zeta potential, scanning electron microscopy (SEM) and x-ray diffraction (XRD) analysis. FTIR analysis showed that betacyanins were adsorbed on kaolin via hydrogen bonding. Zeta potential analysis confirmed the adsorption of betacyanins on kaolin. The intercalation of betacyanins between kaolin platelets was observed by XRD. SEM revealed that CP-Kaolin was well dispersed and embedded within the starch matrix. It was found that the addition of 10 wt% of CP-Kaolin increased the water resistance, tensile strength and thermal stability of starch film. Moreover, starch film containing 10 wt% of CP-Kaolin was sensitive to the change in pH of the fish during storage. Therefore, the addition of CP-Kaolin improved the properties of starch film and starch film composite with CP-Kaolin could be applied as a smart packaging in the food industry.

Changes in chilled beef packaged in starch film containing sea buckthorn pomace extract and quality changes in the film during super-chilled storage.

This study aimed to evaluate the effects of super-chilled storage (-1.3 °C) combined with starch film packaging containing different contents of sea buckthorn pomace extract (SSF, 0, 1, 2, and 3%, w/w) on the quality of chilled beef. The release kinetics, microstructure, and mechanical properties of the film were also measured to investigate its suitability for super-chilled storage. The results of the meat quality assessment showed that the L*, a*, and sensory evaluation values of the SSF-3% samples were significantly higher (P < 0.05), and the pH, b*, thiobarbituric acid reactive substance (TBARS), total volatile basic nitrogen (TVB-N), and total viable count (TCA) were significantly lower (P < 0.05) than the SSF-0%. The release of SBP from the SSF film was controlled by diffusion. Furthermore, SSF-3% was found to have a compact microstructure and good mechanical properties at the end of the super-chilled storage. The results demonstrated that SSF is an effective packaging material for beef at super-chilling temperatures.

Synthesis, characterization, and utilization of potato starch nanoparticles as a filler in nanocomposite films.

The nanoparticles for the preparation of nanocomposite starch films were synthesized from potato starch using the acid hydrolysis method. The films were prepared by incorporating starch nanoparticles into the film formulation at 0.5, 1, 2, 5, and 10% level of total starch. The control starch film was prepared without the incorporation of starch nanoparticles (SNPs) in film formulation. The starch and SNPs were analyzed for physicochemical and morphological properties. The absorption capacity of SNPs for water and oil was significantly (p < 0.05) lower as compared to native starch. Whereas, the swelling power and solubility of SNPs were significantly (p < 0.05) higher than the swelling power and solubility of starch, respectively. The starch granules were oval and spherical with regular surfaces whereas the SNPs had irregular cracked exteriors spaces. The water vapor transmission rate (WVTR) from nanocomposite starch films was significantly (p < 0.05) lower than the control starch film. The burst strength of films was increased significantly (p < 0.05) with an increased level of SNPs incorporation in film formulation. The incorporation of SNPs increased film thickness and biodegradability. Thus, the present study revealed that the incorporation of SNPs in film formulation resulted in improved film properties.

Effect of a sea buckthorn pomace extract-esterified potato starch film on the quality and spoilage bacteria of beef jerky sold in supermarket.

A new food packaging material was developed for beef jerky. The material consists of an esterified potato starch film with 3 different concentrations (2%, 4%, and 6%, w/w) of sea buckthorn pomace extract. The packaged beef jerky was kept in supermarket. The sea buckthorn pomace extract-esterified potato starch film (SPF) packaging significantly reduces the water loss, L*, a*, thiobarbituric acid reactive substances (TBARS) and the total volatile basic nitrogen (TVB-N) of beef jerky during storage (p < 0.05), demonstrating a protective effect to reduce the deterioration of the quality. However, a high content of sea buckthorn pomace extract in film (6%) also affects the smell of beef jerky. Moreover, SPF effectively inhibits the growth of common spoilage bacteria in beef jerky. These results demonstrated that SPF reduces the deterioration rate of the beef jerky and the decreases the spoilage by bacteria, which both gives SPE a high potential as a new packaging material.

Comparative study on properties of starch films obtained from potato, corn and wheat using 1-ethyl-3-methylimidazolium acetate as plasticizer.

Starch films are gaining attention as substitutes of synthetic polymers due to their biodegradability and low cost. Some ionic liquids have been postulated as alternatives to glycerol, one of the best starch plasticizers, due to their great capacity to form hydrogen bonds with starch and hence great ability of preventing starch retrogradation and increasing film stability. In this work, [emim+][Ac-]-plasticized starch films were prepared from potato, corn and wheat starch. The effect of starch molecular structure in terms of granular composition (amylose and phosphate monoester contents) and molecular weight (Mw) on film properties was evaluated. Potato starch films were the most amorphous because of the higher Mw and phosphate monoester content of potato starch, both contributing to a lower rearrangement of the starch chains making the crystallization process difficult. In contrast, corn and wheat starches lead to more crystalline films because of their lower Mw, which may imply higher mobility and crystal growth rate, and lower phosphate monoester content. This more crystalline structure could be the responsible of their better mechanical properties. [emim+][Ac-] can be considered suitable for manufacturing starch films showing corn and wheat starch films similar properties to synthetic low-density polyethylene, but involving a simple and environmentally-friendly process.

Improving properties of normal maize starch films using dual-modification: Combination treatment of debranching and hydroxypropylation.

Structure and properties of films made from native, debranched, hydroxypropylated and debranched/hydroxypropylated normal maize starches were determined and compared. The modified starch films were much smoother and more integrated than native starch film. Especially, the particles were not observed in dual-modified starch film but in debranched starch film, which might result from amylose recrystallization. Debranching substantially decreased elongation at break of starch films from 39.2% to 8.4% and hydroxypropylation decreased tensile strength from 4.82 to 2.92 MPa, indicating neither debranching nor hydroxypropylation could comprehensively improve the film properties. After dual-modification, elongation at break and tensile strength of the film were increased to 57.2% and 7.35 MPa, respectively. Moreover, the barrier performance of films was in the order of hydroxypropylated starch film < native starch film < dual-modified starch film < debranched starch film. It was suggested that dual-modification could be an effective approach to obtain starch films with tailor-made properties.

Effects on Surface and Physicochemical Properties of Dielectric Barrier Discharge Plasma-Treated Whey Protein Concentrate/Wheat Cross-Linked Starch Composite Film.

Dielectric barrier discharge (DBD) plasma is a new type of polymer surface modification technology. This study is mainly about the changes in film surface structure and physicochemical properties of whey protein concentrate (WPC)/wheat cross-linked starch (WCS) composite films after DBD plasma treatment with different plasma parameters. The results show that the proper plasma treatment parameters (400 W to 60 s) can increase the surface roughness, tensile strength, barrier properties, and thermal stability of the edible film and decrease elongation at break and the water contact angle. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction showed that DBD plasma treatment could increase the content of oxygen-containing groups on the WPC/WCS film surfaces instead of damaging the internal crystal structure. The results showed that use of proper DBD plasma treatment technology has a positive effect on the mechanical and barrier properties and thermal stability of WPC/WCS films. PRACTICAL APPLICATION: DBD plasma treatment can improve the mechanical, barrier, and thermal properties of WPC/WCS films without generating any pollution. The DBD plasma can be potentially applied in the enhancement of edible film properties. WPC/WCS films are more environmentally friendly than plastics and can be a replacement for traditional plastics.

Effect of essential oil and surfactant on the physical and antimicrobial properties of corn and wheat starch films.

The present study describes the microstructure, physical (tensile strength, elongation at break, water-vapor permeability, optical characteristics) and antimicrobial properties of biodegradable films prepared by incorporating different concentrations of lemon essential oil (LO) and surfactants (Span 80, Tween 80) into corn and wheat (CW) starch film. Results showed that the incorporation of LO provoked a decrease in water content, transparency, whiteness index (WI), water vapor permeability (WVP), solubility and tensile strength properties. Higher b*, elongation and haze values were observed in CW-LO composite films. Films with LO, especially at higher concentrations, were more effective against all tested bacteria than the control films. The films' surface and cross-section morphology was different depending on the LO contents. Compared with the CW-1LO film, the addition of surfactants significantly increased antimicrobial activity, solubility, haze, surface coarseness and porosity; remarkably decreased tensile strength and transparency. The film containing only Tween 80 showed higher b*, water content, solubility and WVP, lower WI and elongation when compared with the film containing only Span 80. These properties with some good physical and antimicrobial characteristics suggest applications for CW-LO-T/S film in a wide range of food products.

Effect of amylose:amylopectin ratio and rice bran addition on starch films properties.

The influence of the amylose:amylopectin ratio on the properties of pea, potato and cassava starch films and the effect of the incorporation of rice bran of two different particle sizes were studied. The structural, mechanical, optical and barrier properties of the films were analyzed after 1 and 5 weeks. The high content of amylose gave rise to stiffer, more resistant to fracture, but less stretchable films, with lower oxygen permeability and greater water binding capacity. Although no changes in the water vapour permeability values of the films were observed during storage, their oxygen permeability decreased. Throughout storage, films became stiffer, more resistant to break, but less stretchable. Rice bran with the smallest particles improved the elastic modulus of the films, especially in high amylose content films, but reduced the film stretchability and its barrier properties, due to the enhancement of the water binding capacity and the introduction of discontinuities.

Preparation and characterization of bionanocomposite films based on potato starch/halloysite nanoclay.

In this research casting method was used to prepare potato starch based bio-nanocomposite films with halloysite nanoclay as the reinforcing materials. The composition included potato starch with 40% (w/w) of a mixture of sorbitol/glycerol (weight ratio of 3 to 1as plasticizer) with nanoclay (0-5% w/w). The films were dried under controlled conditions. Physicochemical properties such as solubility in water, water absorption capacity (WAC), water vapour permeability (WVP), oxygen permeability, and mechanical properties of the films were measured. Results showed that by increasing the concentration of nanoclay, mechanical properties of films were improved. Tensile strength was increased from 7.33 to 9.82MPa, and elongation at break decreased from 68.0 to 44.0%. Solubility in water decreased from 35 to 23%, and heat seal strength increased from 375 to 580N/m. Also incorporation of clay nanoparticles in the structure of biopolymer decreased permeability of the gaseous molecules. In summary, addition of halloysite nanoclay, improve the barrier and mechanical properties of potato starch films and this bionanocomposites have high potential to be used for food packaging purposes.

Antibacterial, mechanical, and barrier properties of sago starch film incorporated with Betel leaves extract.

The antimicrobial, mechanical and barrier properties and light transmission of sago starch film incorporated with different percentage of Betel leaf extract (5%, 10%, 20%, and 30%) were evaluated. With regard to mechanical properties, tensile strength decreased when the percentage of extract increased. Elongation at break (%) and seal strength (N/m) increased with increasing percentage of extract from 5% to 20%, while decreased for films containing 30% extract due to heterogeneity of films in this percentage. With regard to barrier properties, water vapour and oxygen barrier properties decreased in all samples when percentage of the extract increased. Antimicrobial activity of all the films increased against both Gram positive and Gram negative bacteria as percentage of Betel leaf extract increased, except for Psuedomonas aeruginosa, which was not susceptible at any percentage of the extract.