Curcumin-loaded carboxymethyl cellulose/sodium alginate films with enhanced solubility and bioactivity for freshness monitoring of fish and beef.

Synergistic antimicrobial and barrier enhancement in mushroom extract-loaded gelatin-chitosan films reinforced with tannic acid and curcumin for fresh chicken shelf-life extension.

The escalating need for biodegradable packaging has driven search for sustainable alternatives to synthetic plastics for efficient food products packaging. This research presents a functional gelatin (Gl)-tannic acid (TA)-coated chitosan (Ch) based composite film incorporating mushroom extract (ME) and curcumin extract (CE), which was developed for fresh chicken preservation in refrigerated conditions. The mechanical strength of composite biodegradable films was markedly enhanced when compared to gelatin. The structural and morphological analysis supported strong interactions between components and the development of a compact and uniformly structured polymer matrix. The optimized Gl/TA@Ch/ME/CE film showed reduced moisture content (9.8%), lower solubility (22.4%), decreased swelling (28.5%), and 51% lower water vapour transmission rate, UV-blocking properties and improved low oxygen permeability (1.3 ± 0.15 × 10-9 g·cm/cm2·s). The film exhibited superior antioxidant activity (25.83%), total phenolic content (52.12 μg GAE/mL), and significant antibacterial performance against strains of E. coli and S. aureus. Plant toxicity and developmental toxicity on zebrafish and 97% biodegradation within 48 h confirmed safety and good biocompatibility. Application of the optimized film to the fresh chicken samples significantly reduced the weight loss, delayed pH increase, preserved the texture, and reduced the microbial growth. These results suggest the synergistic effect of tannic acid-coated chitosan and gelatin led to enhancement of strength and stability of the film, and curcumin extract and mushroom extract improved functionality, antimicrobial and antioxidant activity. This research establishes an innovative strategy for fabricating high-performance, bioactive packaging composite films exhibiting superior potential for food safety applications.

Additive enhancement of biodegradability and antibacterial performance in thermoplastic starch/chitosan films incorporating oregano essential oil and silver-zinc oxide nanoparticles.

This study presents a novel thermoplastic starch-chitosan composite film, enhanced with oregano essential oil and silver-zinc oxide (Ag-ZnO: 1%) nanoparticles, designed to overcome the limitations of conventional biopolymer packaging. The synergistic combination of these additives significantly improved mechanical strength (tensile strength: 72.86 to 98.72 MPa), stiffness (Young's modulus), and reduced water uptake by up to 25% compared to unmodified controls. Rigorous biodegradation tests under UV, soil, and aqueous conditions demonstrated accelerated environmental breakdown, with up to 39.53% weight loss after one month under UV exposure. Antimicrobial assays showed inhibitory activity against the tested microorganisms, with inhibition zones of 42 mm against Staphylococcus aureus and 33 mm against Escherichia coli. These results highlight the multifunctional advantages of integrating biopolymers, essential oils, and nanometallic agents, and support a rational strategy for developing sustainable food-packaging materials with improved physical, degradative, and antimicrobial performance.

Molecular interaction and synergistic effects of silver nanoparticles capped by thesinic acid in sodium alginate films: Toward active preservation and intelligent freshness monitoring

This study reported a multifunctional sodium alginate (SA) film enhanced with silver nanoparticles (AgNPs) for pork preservation and freshness monitoring. Spectroscopic analyses confirmed that thesinic acid (CBDA-11) served as a dual bio-reductant and capping ligand, facilitating the green synthesis of stable AgNPs. Those nanoparticles established a dense cross-linked network with the SA matrix, achieving an extraordinary tensile strength of 101 MPa while enhancing water vapor barriers and UV–vis shielding (>99.86% at 200–280 nm). The films exhibited potent antibacterial efficacy and robust antioxidant activity (84.54% ABTS scavenging). In practical applications, SA-CBDA-11-Ag films effectively retarded myoglobin oxidation, delayed protein degradation, and significantly inhibited volatile basic nitrogen accumulation and microbial proliferation, extending pork shelf life to 8 days. Furthermore, the film functioned as a colorimetric sensor, showing a pH-dependent visual transition for freshness monitoring. This work highlighted the potential of AgNPs-based films as advanced active-intelligent systems for sustainable food preservation.

Smart and active biocomposite films from tamarind seed starch, MCC, and trans-cinnamaldehyde for sustainable food packaging

Development of pH-responsive food packaging from chitosan incorporated with nano-curcumin and anthocyanin from black mulberry (Morus nigra L.)

The growing demand for sustainable and intelligent food packaging has driven the development of biodegradable materials with real-time spoilage detection capabilities. Conventional petroleum-based packaging materials pose environmental and health risks due to micro- and nano-plastic contamination. This study presented pH-responsive chitosan films incorporating anthocyanin-rich black mulberry extract (BME) and nanocurcumin as natural color indicators for food freshness monitoring. The BME concentration was fixed at 0.9 mg/g chitosan, while nano-curcumin (0.03–0.3 g/g chitosan) varied to assess its effects on film micro-structure, physical properties, and functionality. Results showed that anthocyanins improved pH-sensitive color changes, making the films effective spoilage indicators. While low nano-curcumin concentrations reduced water vapor permeability (WVP) and tensile strength, higher levels enhanced optical properties, antioxidant activity, and color stability. The optimal formulation (0.21 g/g chitosan) provided a balance between mechanical strength and spoilage detection, making it suitable for meat and seafood applications. This research contributed to food technology and management by offering an eco-friendly alternative to synthetic freshness indicators, promoting food safety, shelf-life extension, and waste reduction

Development and characterization of bioactive citric acid-crosslinked chitosan films functionalized with sorghum extracts.

While chitosan has emerged as a leading biodegradable alternative to petroleum-based plastics, its high moisture sensitivity and limited active functionality often compromise its barrier performance and shelf-life extension capabilities in food-packaging applications. In this study, citric acid-crosslinked chitosan films plasticized with glycerol and functionalized with sorghum glume extracts were developed and characterized. Film thickness remained uniform (0.046-0.056 mm), indicating good casting reproducibility, with reduced water sensitivity, resulting in moderate water solubility (16.8-19.5%), and low water vapour permeability (0.533-0.605 × 10-9 g·m-1·s-1·Pa-1). Increasing glycerol content enhanced film flexibility, with EAB reaching up to 53.47%. Sorghum extracts improved the functional performance of the films, reducing transparency and increasing UV-light shielding while enhancing antioxidant activity. The highest antioxidant performance was observed in films containing 10% extract. SEM analysis revealed smooth, homogeneous, and defect-free surfaces, whereas FTIR and DSC analyses suggest strong intermolecular interactions leading to improved thermal stability and matrix cohesion. The immobilized 3-deoxyanthocyanidins exhibited pH-dependent color responses across a pH range of 1-12 and maintained their coloration under alkaline conditions, reflecting their inherent stability. However, the gradual color transitions indicate greater suitability for active antioxidant packaging than intelligent pH-indicator applications. Moreover, 10% extract-loaded films represent the most promising candidates due to their superior functional performance. The incorporation of sorghum glume extract transformed chitosan films into active bio-based systems with enhanced antioxidant protection, improved light barrier properties, and maintained physicochemical stability.