Polyvinyl alcohol/xanthan gum composite film with excellent food packaging, storage and biodegradation capability as potential environmentally-friendly alternative to commercial plastic bag

Robust construction of konjac glucomannan/polylactic acid nanofibrous films incorporated with carvacrol via microfluidic blow spinning for food packaging

In recent years, the application of biopolymer-based nanofibers prepared via microfluidic blow spinning (MBS) for food packaging has continuously increased due to their advantages of biocompatibility, biodegradability, and safety. However, the poor spinnability, undesirable water barrier capacity, and loss of antibacterial and antioxidant properties of biopolymer-based nanofibers strictly restrict their real-world applications. In this work, carvacrol (CV) incorporated konjac glucomannan (KGM)/polylactic acid (PLA) nanofibrous films (KP-CV) were produced by MBS. The FTIR spectra and XRD analysis revealed the hydrogen bonding interactions among CV, PLA, and KGM, thus significantly improving the TS of KP-CV nanofibrous films from 0.23 to 1.27 MPa with increased content of CV from 0 % to 5 %. Besides, KP-CV nanofibrous films showed improved thermal stability, excellent hydrophobicity (WCA: 128.19°, WVP: 1.02 g mm/m2 h kPa), and sustained release of CV combined with good antioxidant activities (DPPH radical scavenging activity: 77.51 ± 1.57 %), and antibacterial properties against S. aureus (inhibition zone: 26.33 mm) and E. coli (inhibition zone: 22.67 mm). Therefore, as prepared KP-CV nanofibrous films can be potentially applied as packaging materials for the extended shelf life of cherry tomatoes.

Review on emerging trends and challenges in the modification of xanthan gum for various applications

This review explores the realm of structural modifications and broad spectrum of their potential applications, with a special focus on the synthesis of xanthan gum derivatives through graft copolymerization methods. It delves into the creation of these derivatives by attaching functional groups (-OH and -COOH) to xanthan gum, utilizing a variety of initiators for grafting, and examining their diverse applications, especially in the areas of food packaging, pharmaceuticals, wastewater treatment, and antimicrobial activities. Xanthan gum is a biocompatible, biodegradable, less toxic, bioactive, and cost-effective natural polymer derived from Xanthomonas species. The native properties of xanthan gum can be improved by cross-linking, grafting, curing, blending, and various modification techniques. Grafted xanthan gum has excellent biodegradability, metal binding, dye adsorption, immunological properties, and wound healing ability. Owing to its remarkable properties, such as biocompatibility and its ability to form gels resembling the extracellular matrix of tissues, modified xanthan gum finds extensive utility across biomedicine, engineering, and the food industry. Furthermore, the review also covers various modified derivatives of xanthan gum that exhibit excellent biodegradability, metal binding, dye adsorption, immunological properties, and wound healing abilities. These applications could serve as important resources for a wide range of industries in future product development.

Production and application of xanthan gum-prospects in the dairy and plant-based milk food industry: a review

Xanthan gum (XG) is an important industrial microbial exopolysaccharide. It has found applications in various industries, such as pharmaceuticals, cosmetics, paints and coatings, and wastewater treatment, but especially in the food industry. The thickening and stabilizing properties of XG make it a valuable ingredient in many food products. This review presents a comprehensive overview of the various potential applications of this versatile ingredient in the food industry. Especially in the plant-based food industries due to current interest of consumers in cheaper protein sources and health purposes. However, challenges and opportunities also exist, and this review aims to identify and explore these issues in greater detail. Overall, this article represents a valuable contribution to the scientific understanding of XG and its potential applications in the food industry.

Facile exfoliation and physicochemical characterization of Thespesia populnea plant leaves based bioplasticizer macromolecules reinforced with polylactic acid biofilms for packaging applications

Plasticizers are active ingredients added to the polymer to increase its workability. Since synthetic plasticizer is not ecofriendly and toxic in nature, it is a real cause for concern. On this basis, our study focuses on plasticizer extraction from plant-based resources. In this research work, Thespesia populnea leaves are utilized for the isolation of biological macromolecules with a plasticizing effect for biofilm applications. This extraction process is done through solvent extraction, amination, slow pyrolysis, and surface catalysis process. The physico-chemical and microstructural characterization of novel plasticizer particles were studied for the first time. The lower crystallinity index and crystalline size obtained from X-ray diffraction is 50.08 % and 20.45 nm respectively. Energy dispersive spectroscopy, particle sizer analysis, atomic force microscopy, and scanning electron microscopy are used to assess surface morphology of this plasticizer. The thermogram and differential thermal analysis curves give the information about degradation behavior of plasticizers and their thermal stability. The glass transition temperature of the extracted plasticizer is 60.56 °C. The plasticizing effect of the plasticizer is studied through film fabrication of polylactic acid which was blended with the extracted plasticizer. The mechanical property of biofilm was improved with the addition of plasticizer. The elongation break percentage (for 5 % plasticizer 46.12 %) was increased compared to others with moderate tensile strength. However, the tensile and elongation modulus decreases with the increase of plasticizer content. The crystallinity of the PLA film was improved after the plasticization. The thermal stability also increased with 3 % addition of the plasticizer. The isolated plasticizer was soluble in water and its molecular weight ≈380.

Constructing a biodegradable carrageenan based food packaging film according to the synergistic strategies between peppermint essential oil and thymol

The research and development trend of food packaging is changing from synthetic polymers to eco-friendly materials such as polysaccharides and other hydrocolloids, aiming to solve the problem of pollution from plastic wastes. In this work, a biodegradable food packaging noted KC/PT film was constructed using konjac glucomannan (KGM)/carrageenan (CAR) composite as the matrix and peppermint essential oil (PO)/thymol (THY) with synergistic effect as the reinforcements. The KC/PT film showed great mechanical properties, UV-blocking activity, increased water contact angle and reduced water vapor permeability. Due to the synergistic effect between PO and THY, the KC/PT film showed excellent antioxidant performance and antibacterial behavior against Escherichia coli ATCC 25922, Listeria monocytogenes ATCC 19115 and Staphylococcus aureus ATCC 6538. The antibacterial mechanism was further illustrated. The prepared KC/PT film, as a unique packaging film, not only successfully extended the shelf life of strawberry to 16 days at 4 °C, but also well expressed its environmental friendliness that it could nearly degrade after 47 days in natural soil conditions. Most importantly, the film exhibited good stability in terms of mechanical properties, antioxidant activity and antibacterial performances after 4 months storage. Therefore, the film the KC/PT film has great potentials in the field of food packaging area.

Preparation and characterization of egg white protein film incorporated with epigallocatechin gallate and its application on pork preservation

The aim of this study was to develop the composite films with antioxidant and biodegradable activity based on egg white protein (EWP) and epigallocatechin gallate (EGCG). Water susceptibility, light transmittance, microstructure and antioxidant properties of the composite films without and with EGCG were fully characterized. It was noted that the addition of EGCG might decrease the moisture content, water solubility and swelling capacity. SEM micrographs revealed that discontinuous blocks and rough surfaces were caused by increasing concentration of EGCG, whereas compact and homogeneous particles appeared when the concentration of EGCG reached to 80 μmol/L. Moreover, the biodegradability of the composite films was demonstrated by the soil degradation properties that they can be almost completely degraded within ten days. Experimental results on the application in chilled fresh pork showed that the EWP-based films could play an antioxidant role when incorporated with EGCG, indicating their great potential for food packaging.

Sustainable polylactide materials with the function of blocking a specific wavelength of light based on aloe-emodin

Polylactide, a biodegradable polymer, can alleviate white pollution, but the use of polylactide in food packaging is limited by high transmittance to light with a specific wavelength, UV (185-400 nm) and short-wavelength visible (400-500 nm) light. Herein, the polylactide end-capped with renewable light absorber aloe-emodin (PLA-En), is blended with commercial polylactide (PLA) to fabricate the polylactide film with the function of blocking light with a specific wavelength, PLA/PLA-En film. Only 40 % of light around 287 and 430 nm transmits through PLA/PLA-En film incorporating 3 mass% of PLA-En, while the film still maintains good mechanical properties and high transparency more than 90 % at 660 nm because of the good compatibility with PLA. The PLA/PLA-En film exhibits stable light-blocking properties under light irradiation and anti-solvent migration under the immersion of fat simulant. Almost no PLA-En migrated out of the film with the molecular weight of PLA-En only 2.89 × 104 g/mol. Compared with PLA film and commercial PE plastic wrap, the designed PLA/PLA-En film exhibits a better preservative effect on riboflavin and milk for inhibiting the production of 1O2. This study offers a green strategy for developing UV and short-wavelength light protective food package film based on renewable resource.

Correlation between Mechanical and Morphological Properties of Polyphenol-Laden Xanthan Gum/Poly(vinyl alcohol) Composite Cryogels

This study aimed to evaluate the effect of the synthesis parameters and the incorporation of natural polyphenolic extract within hydrogel networks on the mechanical and morphological properties of physically cross-linked xanthan gum/poly(vinyl alcohol) (XG/PVA) composite hydrogels prepared by multiple cryo-structuration steps. In this context, the toughness, compressive strength, and viscoelasticity of polyphenol-loaded XG/PVA composite hydrogels in comparison with those of the neat polymer networks were investigated by uniaxial compression tests and steady and oscillatory measurements under small deformation conditions. The swelling behavior, the contact angle values, and the morphological features revealed by SEM and AFM analyses were well correlated with the uniaxial compression and rheological results. The compressive tests revealed an enhancement of the network rigidity by increasing the number of cryogenic cycles. On the other hand, tough and flexible polyphenol-loaded composite films were obtained for a weight ratio between XG and PVA of 1:1 and 10 v/v% polyphenol. The gel behavior was confirmed for all composite hydrogels, as the elastic modulus (G') was significantly greater than the viscous modulus (G″) for the entire frequency range.