Synergistic effect of the sequential intercalation of three types of surfactants in the exfoliation degree of bentonite clay in films of cassava

Thermoplastic starch/bentonite clay nanocomposite reinforced with vitamin B2: Physicochemical characteristics and release behavior

This study presents the development and characterization of a nanocomposite material, consisting of thermoplastic starch (TPS) reinforced with bentonite clay (BC) and encapsulated with vitamin B₂ (VB). The research is motivated by the potential of TPS as a renewable and biodegradable substitute for petroleum-based materials in the biopolymer industry. The effects of VB on the physicochemical properties of TPS/BC films, including mechanical and thermal properties, water uptake, and weight loss in water, were investigated. In addition, the surface morphology and chemical composition of the TPS samples were analyzed using high-resolution SEM microscopy and EDS, providing insight into the structure-property relationship of the nanocomposites. The results showed that the addition of VB significantly increased the tensile strength and Young's modulus of TPS/BC films, with the highest values observed for nanocomposites containing 5 php of VB and 3 php of BC. Furthermore, the release of VB was controlled by the BC content, with higher BC content leading to lower VB release. These findings demonstrate the potential of TPS/BC/VB nanocomposites as environmentally friendly materials with improved mechanical properties and controlled release of VB, which can have significant applications in the biopolymer industry.

Development and characterization of taro starch-casein composite bioactive films functionalized by micellar pomegranate peel extract (MPPE)

Starch-casein composite (solid matter content) based bioactive films incorporated with micellar pomegranate peel extract (MPPE) at different concentrations (10, 25, 50, and 100 wt% with respect to base solid matter content) were developed. The extract-free film was used as a control. The bioactive films were characterized for physicochemical, mechanical, barrier, structural, thermal, and bioactive properties. Decreased ζ-potential and surface tension, increased particle size, and improved rheological properties of MPPE added film-forming dispersion (FFD) were recorded. Among all the physical properties of bioactive films, only contact angle was reduced. An increase in MPPE concentration exhibited less hardness, more extensibility, and an excellent barrier to water vapor permeability than the control film. Increased MPPE concentration showed a decline in transparency (%) and lightness (L*) resulting into distinct color to the film. Structural compactness and integrity of the films were confirmed by SEM and XRD patterns. Improved functional interaction and thermal reliability of bioactive films were noted. The interaction patterns between starch-casein composite and MPPE bioactives indicated the development of covalent links. Excellent bioactivities with the slow release of bioactives in hydroalcoholic environment, confirmed by the kinetic study. Remarkable antibacterial effect was noted against E. coli and S. aureus by the films. Overall, increasing the concentration of MPPE in bioactive film showed improved physicochemical strength; hence, prepared bioactive films could be used as food coatings.

Mechanical and barrier properties of starch blend films enhanced with kaolin for application in food packaging

Starch blend films of native cassava starch and medium distarch phosphate cassava starch (crosslinked cassava starch) were prepared by solution casting. The effects of kaolin content on the water resistance and mechanical properties of the starch blend films were investigated. The addition of 10 wt% kaolin to the starch blend film lowered water vapor permeability to 3.51 × 10^-5 g m day^-1 m^-2 Pa^-1, water solubility to 31.60% and raised tensile strength to 2.99 MPa. At this loading of kaolin, the structural integrity of the starch blend film was maintained during immersion in water and thermal stability was enhanced. Scanning electron microscopy revealed kaolin to be well dispersed and embedded within the starch matrix. In summary, the starch blend film composite with 10 wt% kaolin had interesting properties as a material to replace non-biodegradable synthetic plastics for packaging, particularly sachets for food products.

Development and Characterization of Semi-Refined Iota Carrageenan/SiO2-ZnO Bionanocomposite Film with the Addition of Cassava Starch for Application on Minced Chicken Meat Packaging

In the current study, film based on semi-refined ι-carrageenan/cassava starch (SRiC/CS) incorporated with SiO₂-ZnO nanoparticles was fabricated and characterized to deal with serious environmental problems resulting from plastic packaging materials. This study aimed to evaluate film properties with the variation of SRiC/CS proportions of bionanocomposite films for application to minced chicken meat packaging. Increasing CS portion contributed to increased transparency, reduced surface roughness, and decreased mechanical properties of films. The variable significantly (p < 0.05) increased the water vapor permeability (WVP) and reduced the water solubility of films. The incorporation of the nanoparticles significantly (p < 0.05) increased UV screening, decreased WVP, and enhanced the antimicrobial activity of films. Furthermore, the substitution of 0.5 wt% (weight percentage) CS provided the best film characteristics. Based on the color and the total volatile base nitrogen (TVBN) results, SRiC film incorporated with the nanoparticles preserved minced chicken quality up to six days. Thus, the developed films are desirable for biodegradable food packaging.

Effect of Clay Nanofillers on the Mechanical and Water Vapor Permeability Properties of Xylan-Alginate Films

In this study, xylan–alginate-based films were reinforced with nanoclays (bentonite or halloysite) by the solvent casting technique. The effect of the nanoclay loadings (1–5 wt %) on various properties—mechanical, optical, thermal, solubility, water sorption, and water vapor permeability (WVP)—of the xylan–alginate films were examined for their application as food packaging materials. A 5 wt % loading of either bentonite or halloysite resulted in a 49% decrease of the WVP due to the impermeable nature of the silicate layers that make up both bentonite and halloysite. Thermal stability and solubility of the nanocomposite films were not significantly influenced by the presence of the nanoclays, whereas the optical properties were significantly improved when compared to neat xylan–alginate blend. In general, films reinforced with bentonite exhibited superior mechanical and optical properties when compared to both halloysite-based nanocomposite and neat films.

Change in characteristics of film based on rice starch blended with sucrose, maltose, and trehalose after storage

The characteristics of rice starch film blended with sucrose, maltose, and trehalose at concentrations of 0%, 10%, 20%, or 30% (w/w of the starch weight) were investigated. Relative crystallinity (RC) of the rice starch film as determined by X-ray increased with increasing sucrose concentration and the RC tended to decrease with an increasing concentration of maltose and trehalose. RC was inhibited by adding sugar in the order of trehalose, maltose, and sucrose after 28 days storage. The rice starch film with 30% added sugar showed a homogeneous matrix and a lower frequency chemical shift of the proton OH group as determined on the day of preparation; however, the film with 30% added maltose cracked after 28 days storage. Adding sugar as a plasticizer affected the properties of the rice starch film by concentration and type of sugar because of the hydroxyl groups of the sugar. PRACTICAL APPLICATION: Disaccharides, such as sucrose, maltose, and trehalose, could be used as a plasticizer in a rice starch film system. The sugar conformation might be one factor for selecting the sugar to use for starch film system. Trehalose might improve film properties by inhibiting recrystallization after storage.