Comprehensive elucidation of the effect of residual lignin on the physical, barrier, mechanical and surface properties of nanocellulose films

Our study explores the development and characterization of carboxymethyl cellulose (CMC)-based composite films integrated with clay particles and pomegranate peel extract (PE), aiming to inspire the films with natural antimicrobial and antioxidant properties for potential applications in food packaging. We conducted a comprehensive examination of the mechanical, barrier, surface, and degradation properties of these composite films, considering the impacts of incorporating clay particles and PE on their overall performance. Our findings reveal that the inclusion of clay particles enhances the mechanical strength and barrier properties of the films, while PE contributes to antioxidant and antibacterial effects. Namely, after the integration of 3 wt% clay, the tensile strength exhibited a remarkable increase of approximately 300%, accompanied by a notable reduction of 60% in water vapor permeability and 30% in oxygen transmission rate. Furthermore, the integration of PE into CMC films promoted antibacterial activity against 2 g-positive bacterial species, Staphylococcus aureus and Listeria monocytogenes. Additionally, we conducted a life cycle assessment (LCA) to quantify the cradle-to-gate environmental impacts of the developed bio-based active films. When normalized to the functional properties of the films, including mechanical and barrier performance, we observed significant benefits, with reductions of up to 59% after the concurrent incorporation of PE and clay nanosheets. Overall, our study underscores the potential of CMC-based composite films augmented with PE as a promising solution for sustainable food packaging, offering enhanced functionality while reducing environmental impact and increasing food safety.

Effect of LAPONITE® addition on the mechanical, barrier and surface properties of novel biodegradable kafirin nanocomposite films

Biodegradable polymers derived from biomass such as polysaccharides (starches, chitosan, and gums) and proteins (gelatin, soy, and zein) have been explored tremendously as potential food packaging materials. Their unique characteristics, for example, edible, abundance, renewable and low-cost allow these materials to be utilized in many forms such as films and coatings. However, biodegradable polymers exhibit high water vapour permeability and solubility. Functional properties of biodegradable polymers can be enhanced by blending with other polymers, lipids, surfactants, emulsifiers or other additives. Combining some polymers and additives will change the microstructure, mechanical, barrier and surface properties of films. Therefore, surface properties can influence the final applications of films and coatings. Interestingly, surface properties of polymers can be tailored using some treatment. Lack of discussion on surface properties of biodegradable films is noticeable. This chapter presents the surface properties of biodegradable films and coatings from various sources and their characterizations. Some surface treatments on films aiming to improve their characteristics and effect of the surface on active packaging are also discussed.

Improvement of physicochemical, mechanical, thermal and surface properties of anchovy by-product protein films by addition of transglutaminase, and the correlation between secondary structure and mechanical properties

Hexamethyldisiloxane cold plasma treatment and amylose content determine the structural, barrier and mechanical properties of starch-based films

The development of mixed emulsion-based films formed by sodium alginate/gelatin incorporated with canola oil can offer particular properties such as water vapor barrier properties. The different ratios of sodium alginate/gelatin and sodium alginate/gelatin emulsion-based films incorporated with canola oil were developed and their effects on films’ physical, mechanical and barrier properties were assessed. Here we set out to examine whether canola oil addition and different ratio of sodium alginate/gelatin modified physical, mechanical, and barrier properties of films. To do so, the films were prepared by vary the ratio of sodium alginate/gelatin (2.5, 1, 0.5). Canola oil addition induced changes in moisture content, thickness, solubility, water vapor transmission rate (WVTR), percent elongation at break (p<0.05). In addition, it is apparent that varying ratio of sodium alginate to gelatin induced change the mechanical properties of films. The reduction of sodium alginate to gelatin decreased the tensile strength of both films. Improved values of WVTR, tensile strength and solubility at break were observed when the ratio of sodium alginate/gelatin emulsion film incorporated with canola oil was 2.5. Therefore, different ratio of sodium alginate/gelatin incorporated with canola oil can be used to tailor emulsion films with enhanced water vapor barrier and mechanical properties.

Traditional food packaging systems help reduce food wastage, but they also produce environmental impacts when not properly disposed of. Bio-based polymers are a promising solution to overcome these impacts, but they have poor barrier and mechanical properties. This work evaluates two strategies to improve these properties in pectin films: the incorporation of cellulose nanocrystals (CNC) or sodium montmorillonite (MMT) nanoparticles, and an additional layer of chitosan (i.e., a bilayer film). The bionanocomposites and bilayer films were characterized in terms of optical, morphological, hygroscopic, mechanical and barrier properties. The inclusion of the nanofillers in the polymer reduced the water vapor permeability and the hydrophilicity of the films without compromising their visual properties (i.e., their transparency). However, the nanoparticles did not substantially improve the mechanical properties of the bionanocomposites. Regarding the bilayer films, FTIR and contact angle studies revealed no surface and/or chemical modifications, confirming only physical coating/lamination between the two polymers. These bilayer films exhibited a dense homogenous structure, with intermediate optical and hygroscopic properties. An additional layer of chitosan did not improve the mechanical, water vapor and oxygen barrier properties of the pectin films. However, this additional layer made the material more hydrophobic, which may play an important role in the application of pectin as a food packaging material.

The amyloid fibril-stabilized Pickering emulsion significantly enhances the mechanical and barrier properties of Konjac Glucomannan active films for cherry preservation.

Films of 0.11 to 0.13 mm thickness were prepared using gelatins from the skins of cultured freshwater carp species and mammalian gelatins viz., porcine and bovine skin gelatin. A comparative study was made on the physical, mechanical, and barrier properties of these films. The amino acid composition, gel strength, clarity, and gel setting point of the gelatins were also determined. Carp skin gelatins had a lower imino acid content (19.16% to 20.86%) than mammalian skin gelatins (22.91% to 23.7%). Grass carp gelatin had gel strength of 230.2 B that is comparable to the reported value for bovine skin gelatin (227.2 B). The bloom values of rohu and common carp skin gelatins were 188.6 B and 181.3 B, respectively, which were significantly lower than mammalian gelatins. Mammalian gels have significantly higher (P < 0.05) setting temperatures (23.7 to 24.2 °C) than carp skin gelatins. Tensile strength (TS) was lowest for films from common carp and rohu skin gelatin (490 and 497 kg/cm(2), respectively) and highest for porcine skin gelatin film. The degree of transparency (L*) was significantly higher for films from grass carp, bovine hide, and pork skin gelatin films. Carp skin gelatin films had significantly lower water vapor permeability (WVP) and oxygen permeability (OP) than mammalian skin gelatin films, which indicated that carp skin gelatin based films have superior barrier properties than mammalian skin gelatin films.

Physical, thermal, mechanical and barrier properties of pearl millet starch films as affected by levels of acetylation and hydroxypropylation

Potential of polysaccharides for food packaging applications. Part 2/2: An experimental review of the effect of aging conditions on the functional properties of polysaccharide films

Jose Alvarez-Ramirez The recent decades have witnessed a growing interest in the development and application of starch films. Low-cost, sustainability, biodegradability, and long-term stability are the motivations behind the use of starch as a base polymer for film fabrication. The aim of this special issue is to bring together recent research advances in starch films. Articles come from India, China, Australia, Malaysia, Poland, and Mexico, reflecting the widespread interest in the field. The work by Kaur et al. explores the ability of biodegradable chitosan–rice starch films to preserve the quality of peach fruits. The results are promising as the film inhibits the growth of Gram-positive and Gram-negative microorganisms. In a similar research line, the work by Ji et al. reports the antimicrobial effect of incorporating chitosan and calcium bicarbonate particles. Saberi et al. study blends of pea starch and guar gum, arriving at optimal conditions for mechanical properties and water-vapor permeability. Nair and co-workers report that konjac glucomannan–chitosan films incorporated with granular cassava starch and nanosilver improve greatly the water barrier properties. Ren et al. propose glycerol and 1-butyl-3-methylimidazolium chloride as combined plasticizers to improve the thermal stability and tensile strength. Edhirej and collaborators find that the plasticizer type and concentration significantly influence the properties of cassava starch film. Staroszczyk et al. study strategies to improve the mechanical and water-barrier properties of films prepared from starch and clays. Ren and colleagues study water barrier and mechanical properties of innovative starch films reinforced with crosslinked starch nanoparticles. Finally, Garcia-Hernandez et al. study the impact of gelatinization insoluble remnants on the mechanical and water barrier properties of corn starch films. All articles included in this special issue illustrate the scientific and technological efforts to advance the understanding of the mechanisms underlying the stability and protective action of starch films. On behalf of the editorial board, I would like to express enormous gratitude to all authors and reviewers that contributed to this special issue. Jose Alvarez-Ramirez Departamento de Ingeniería de Procesos e Hidráulica Universidad Autónoma Metropolitana-Iztapalapa Apartado Postal 55-534 Iztapalapa, 09340 México Email: jjar@xanum.uam.mx

Edible and active films and coatings as carriers of natural antioxidants for lipid food

Effects of nano-kaolin incorporation into semolina films on the physical, mechanical, thermal, barrier and antimicrobial properties of the resulting bio-nanocomposite films were investigated. The properties included crystal structure (by X-ray diffraction), mechanical resistance, color, Fourier transform infrared spectra, decomposition temperature, water-vapor permeability (WVP), oxygen permeability (OP), and antimicrobial activity against Staphylococcus aureus and Escherichia coli. Kaolin was incorporated into biofilms at various amounts (1, 2, 3, 4, and 5%, w/w total solid). All films were plasticized with 50% (w/w total solid) combination of sorbitol/glycerol at 3:1 ratio. The incorporation of nanokaolin into semolina films decreased OP and WVP. The moisture content and water solubility of the films were found to decrease by nanokaolin reinforcement, and mechanical properties of films were improved by increasing nanokaolin concentration. Tensile strength and Young's modulus increased from 3.41 to 5.44MPa and from 63.12 to 136.18, respectively, and elongation-at-break decreased. The films did not exhibit UV absorption. In conclusion, nanokaolin incorporation enhanced the barrier and mechanical properties of semolina films, indicating the potential application of these bio-nanocomposites in food-product packaging.

Mechanical and water barrier properties of isolated soy protein composite edible films as affected by carvacrol and cinnamaldehyde micro and nanoemulsions