Characterization of glucose-crosslinked gelatin films reinforced with chitin nanowhiskers for active packaging development

Valorization of Seafood Waste for Food Packaging Development

Packaging plays a crucial role in protecting food by providing excellent mechanical properties as well as effectively blocking water vapor, oxygen, oil, and other contaminants. The low degradation of widely used petroleum-based plastics leads to environmental pollution and poses health risks. This has drawn interest in renewable biopolymers as sustainable alternatives. The seafood industry generates significant waste that is rich in bioactive substances like chitin, chitosan, gelatins, and alginate, which can replace synthetic polymers in food packaging. Although biopolymers offer biodegradability, biocompatibility, and non-toxicity, their films often lack mechanical and barrier properties compared with synthetic polymer films. This comprehensive review discusses the chemical structure, characteristics, and extraction methods of biopolymers derived from seafood waste and their usage in the packaging area as reinforcement or base materials to guide researchers toward successful plastics replacement and commercialization. Our review highlights recent advancements in improving the thermal durability, mechanical strength, and barrier properties of seafood waste-derived packaging, explores the mechanisms behind these improvements, and briefly mentions the antimicrobial activities and mechanisms gained from these biopolymers. In addition, the remaining challenges and future directions for using seafood waste-derived biopolymers for packaging are discussed. This review aims to guide ongoing efforts to develop seafood waste-derived biopolymer films that can ultimately replace traditional plastic packaging.

Silk Protein-Based Nanoporous Microsphere for Controllable Drug Delivery through Self-Assembly in Ionic Liquid System

Ionic liquids (ILs) showed a promising application prospect in the field of biomedicine due to their unique recyclability, modifiability, and structure adjustability. In this study, nanoporous microsphere of silk protein and blending with poly(d,l-lactic acid) as model drug delivery was fabricated, respectively, through an IL-induced self-assembly method. Their morphology, structure, and thermal properties were comparably investigated through scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, differential scanning calorimetry, X-ray diffraction, and thermogravimetric analyses, and the interaction mechanisms were also discussed to elucidate the effect of structure on drug delivery kinetics. The pure protein exhibited a bigger nanopore size in the microsphere compared to the composite one, facilitating more effective drug loading up to 88.7%. However, drug release was over 53.5% for the composite during initial 4 h, while pure protein was only about half of the composite. Both of them exhibited sustained slow release after 24 h and anticancer efficacy. Furthermore, the favorable compatibility between drug and microsphere vehicle was found and experienced improved thermal stability upon encapsulation, which could protect the drug molecules in high temperature at 200 °C. When the protein and its composite self-assembled to microspheres in ILs due to electrostatic and hydrophobic interaction, the drug could be infiltrated into the nanoporous matrix through biophysical action, and the protein structure displayed reversible transition during delivery. The sustained slow release from pure SF was attributed to the high β-sheet block action and strong drug-protein interactions, whose strength could be tuned through blending poly(d,l-lactic acid) with protein. These findings indicated that the SF-based nanoporous microspheres formed from IL self-assembled system are an ideal and potential drug delivery vehicle which can be incorporated into various biomaterials in the future.

Design and characterization of edible chitooligosaccharide/fish skin gelatin nanofiber-based hydrogel with antibacterial and antioxidant characteristics

Antibacterial and active packaging materials have gained significant research attention in response to the growing interest in food packaging. In this investigation, we developed hydrogel packaging materials with antibacterial and antioxidant properties by incorporating chitooligosaccharide (COS) and fish skin gelatin (FSG) nanofiber membranes, which readily absorbed water and exhibited swelling characteristics. The nanofiber membranes were fabricated by electrospinning technology, embedding COS within FSG, and subsequently crosslinked through the Maillard reaction facilitated by the addition of glucose. The behavior of conductivity, viscosity, and surface tension in the spinning solutions was analyzed to understand their variation patterns. Scanning electron microscopy (SEM) results revealed that the crosslinked COS/FSG nanofiber membranes possessed a uniform yet disordered fiber structure, with the diameter of the nanofibers increasing as the COS content increased. Remarkably, when the COS content reached 25 %, the COS/FSG nanofiber membranes (CF-C-25) exhibited a suitable fiber diameter of 437.16 ± 63.20 nm. Furthermore, the thermal crosslinking process involving glucose supplementation enhanced the hydrophobicity of CF-C-25. Upon hydration, the CF-H-25 hydrogel displayed a distinctive porous structure, exhibiting a remarkable swelling rate of 954 %. Notably, the inclusion of COS significantly augmented the antibacterial and antioxidant properties of the hydrogel-based nanofiber membranes. CF-H-25 demonstrated an impressive growth inhibition of 90.56 ± 5.91 % against E. coli, coupled with excellent antioxidant capabilities. In continuation, we performed a comprehensive analysis of the total colony count, pH, TVB-N, and TBA of crucian carp. The CF-H-25 hydrogel proved highly effective in extending the shelf life of crucian carp by 2-4 days, suggesting its potential application as an edible membrane for aquatic product packaging.

Construction of carboxymethyl chitosan/PVA/chitin nanowhiskers multicomponent film activated with Cotylelobium lanceolatum phenolics and in situ SeNP for enhanced packaging application

This work focused on the construction of bioactive packaging films based on carboxymethyl chitosan and poly(vinyl alcohol) (CMP) as polymeric matrix and fortified with chitin nanowhiskers, Cotylelobium lanceolatum phenolic extract (CL) and in situ synthesized nano selenium. Extensive morphological, microstructural, physical and mechanical analysis revealed that the nanofillers were well-dispersed and integrated into CMP matrix. Incorporation of the extract and nano selenium produced excellent UV blocking properties without seriously compromising the transparency of the composite (CMP/CNW/CLNS1) film. Moreover, blending of CMP with the filler materials significantly elevated (p < 0.05) the surface hydrophobicity (WCA by 35.4°), water barrier (by 53.86 %), tensile strength (from 29.35 to 33.09 MPa), elongation at break (from 64.28 to 96.48 %), and thermal properties of the resultant CMP/CNW/CLNS1 film, with concomitant reduction in water solubility and swellability. Furthermore, the CMP/CNW/CLNS films exhibited remarkable improvement in antioxidant properties. When used for packaging of peeled fresh garlic cloves, the CMP/CNW/CLNS1 film pouch, not the plain CMP or CMP/CNW film pouches, inhibited weight loss, oxidative browning, and the emergence of black mold on the packaged cloves. The developed CMP/CNW/CLNS1 film demonstrated enhanced capacity to safeguard the quality of packaged food and improved shelf life. Therefore, the present study suggests that incorporation of CNW/CLNS into carboxymethyl chitosan/PVA films is a suitable and facile strategy for the fabrication of films with improved mechanical, physico-chemical and functional properties with great potential for application as a sustainable active packaging material in the food industry.

Nano-chitin: Preparation strategies and food biopolymer film reinforcement and applications

Current trends in food packaging systems are toward biodegradable polymer materials, especially the food biopolymer films made from polysaccharides and proteins, but they are limited by mechanical strength and barrier properties. Nano-chitin has great economic value as a highly efficient functional and reinforcing material. The combination of nano-chitin and food biopolymers offers good opportunities to prepare biodegradable packaging films with enhanced physicochemical and functional properties. This review aims to give the latest advances in nano-chitin preparation strategies and its uses in food biopolymer film reinforcement and applications. The first part systematically introduces various preparation methods for nano-chitin, including chitin nanofibers (ChNFs) and chitin nanocrystals (ChNCs). The nano-chitin reinforced biodegradable films based on food biopolymers, such as polysaccharides and proteins, are described in the second part. The last part provides an overview of the current applications of nano-chitin reinforced food biopolymer films in the food industry.

Characterization and antibacterial behavior of an edible konjac glucomannan/soluble black tea powder hybrid film with ultraviolet absorption

In this study, a KGM/SBTP film was prepared by a blending method using KGM and a soluble black tea film (SBTP) as substrates, and its hygroscopicity, thermal properties, light barrier properties, microstructure, and bacteriostatic properties were evaluated. The results confirmed that compared with the control group, with the increase in the SBTP content, the transmittance of the film in the ultraviolet region significantly reduced, and the water barrier property and thermal stability were improved. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) results indicated that the tea polyphenols interacted with the film substrate. SEM also showed that the structure of the KGM/SBTP films was smooth and flat, and all samples showed no fracture. In addition, the KGM/SBTP mixed membrane had obvious concentration-dependent antibacterial activity. When the concentration of SBTP was 0.9%, the inhibition zones against Staphylococcus aureus and Escherichia coli were 12.30 ± 0.20 mm and 12.05 ± 0.47 mm, respectively.

Characterization and Application in Packaging Grease of Gelatin-Sodium Alginate Edible Films Cross-Linked by Pullulan

Gelatin–sodium alginate-based edible films cross-linked with pullulan were prepared using the solution casting method. FTIR spectroscopy demonstrated the existence of hydrogen bonding interactions between the components, and scanning electron microscopy observed the component of the films, revealing electrostatic interactions and thus explaining the differences in the properties of the blend films. The best mechanical properties and oxygen barrier occurred at a 1:1 percentage of pullulan to gelatin (GP11) with sodium alginate dosing for modification. Furthermore, GP11 demonstrated the best thermodynamic properties by DSC analysis, the highest UV barrier (94.13%) and the best oxidation resistance in DPPH tests. The results of storage experiments using modified edible films encapsulated in fresh fish liver oil showed that GP11 retarded grease oxidation by inhibiting the rise in peroxide and anisidine values, while inappropriate amounts of pullulan had a pro-oxidative effect on grease. The correlation between oil oxidation and material properties was investigated, and water solubility and apparent color characteristics were also assessed.