Biobased Intelligent Food-Packaging Materials with Sustained-Release Antibacterial and Real-Time Monitoring Ability

In situ growth of defective ZIF-8 on TEMPO-oxidized cellulose nanofibrils for rapid response release of curcumin in food preservation

Uncontrolled release of active agents in active packaging reduces antimicrobial efficacy, hindering the effective protection of perishable products from microbial infection. Herein, a novel defective engineering was proposed to design defective and hollow ZIF-8 structures grown on TEMPO oxidized cellulose nanofibrils (TOCNFs) and use them as fast-reacting nanocarriers for loading and controlled release curcumin (Cur) in sodium alginate (SA) active packaging systems (CZT-Cur-SA). By employing stable chelation between tannic acid (TA) and ZIF-8 zinc ions, the connections between zinc ions and imidazole ligands were severed to form a loose and hollow structure, which facilitates the rapid reaction and release of active ingredients triggered by pH changes in the microenvironment. Kinetic tests showed CZT-Cur-SA films released 65.68 % of Cur at pH 6.0 within 24 h, compared to 28.26 % at pH 7.0. These films demonstrated exhibited excellent mechanical properties, antioxidation capacity (82.59 %), reinforced moisture (0.51 × 10-10 g m-1 s-1 Pa-1) and satisfied antimicrobial effects on E. coli (1.69 %) and S. aureus (0.88 %). The optimized CZT-Cur-SA film extended strawberry shelf life to at least 7 days under ambient conditions. Our findings introduce a promising approach to designing responsive, biodegradable active packaging for enhanced food safety.

Functional pH-sensitive film based on pectin and whey protein for grape preservation and shrimp freshness monitoring

A pH-sensitive film was prepared from pectin (P) and whey protein (W), incorporating anthocyanin-rich purple sweet potato extract (PPE) as the pH indicator. The effect of PPE content on the structure and properties of the films and the pH indicating function were determined and evaluated for shrimp freshness and grape preservation. The solubility (60.23 ± 7.36 %) and water vapor permeability (0.15 ± 0.04 × 10-11 g·cm/(cm2·s·Pa)) of the pectin/whey protein/PPE (PW-PPE) film with 500 mg/100 mL PPE were the lowest of the films tested and much lower than PW films without PPE. PW-PPE films were non-cytotoxic and had excellent biodegradability in soil. Grapes coated with PW-PPE film had reduced weight loss from water evaporation, and decay during storage was inhibited. The total color change (ΔE) of the PW-PPE films had a strong linear correlation with the pH of shrimps during storage. PW-PPE films have application potential to monitor the real-time freshness of meat and extend the shelf life of fruit.

Innovative applications of bio-inspired technology in bio-based food packaging

Traditionally, food packaging was used to extend the shelf life of food or to monitor its condition. Inspired by many biological structures found in nature, bio-inspired functional materials for bio-based food packaging have been shown to have significantly improved capabilities over traditional bio-based food packaging materials in various aspects and to attract consumers through novel freshness preservation features. This review synthesizes recent advances in bio-inspired bio-based food packaging materials that mimic the structure of natural organisms with specific functionalities, with examples of specific biomimetics in different enhancement areas. In general, bio-based materials have certain disadvantages compared to polymer materials, so there is an urgent need for improvement and enhancement in many areas. Biomimicry further inspires the realization of enhancing some basic functions of bio-based materials for packaging (hydrophobicity, mechanical strength, antimicrobial properties, optical properties) and endowing bio-based materials with more new responsiveness and other functions. What is more interesting is that the inspiration of bionics is taken from nature, and such a perspective can also promote further progress and innovation of bio-based food packaging materials.

The latest research progress on polysaccharides-based biosensors for food packaging: A review

In recent years, polysaccharide-based biosensors have emerged as promising technologies for intelligent food packaging, offering innovative solutions to enhance food quality and safety. This review highlights advancements in designing, developing, and applying these biosensors, particularly those utilizing polysaccharides such as chitosan, cellulose and alginate. Engineered with nanomaterials like ZnO, silver, and carbon nano-tubes demonstrated high sensitivity in real-time monitoring of food spoilage indicators, including pH changes, volatile nitrogen compounds and microbial activity. We discuss the electrochemical properties of these biosensors, highlighting how the integration of electrochemical methods significantly improves their detection capabilities within packaging environments, leading to sensor sensitivity enhancement, greater accuracy, and spoilage detection, ultimately extending the shelf life of perishable food products. Additionally, the review addresses the practical challenges of industrial implementation and explores future research directions for optimizing sensor functionality and scalability. The findings underscore the potential of polysaccharide-based intelligent packaging as a sustainable and effective alternative to conventional methods, paving the way for broader commercial adoption.

A cellulose-based light-management film incorporated with benzoxazine resin/tannic acid exhibiting UV/blue light double blocking and enhanced mechanical property

Cellulose, as a biomass resource, has attracted increasingly attention and extensive research by virtue of its widely sources, ideal degradability, good mechanical properties and easy modification due to its rich hydroxyl groups. Nevertheless, it is still a challenge to attain high performance cellulose-based composite film materials with diverse functional combinations. In this work, we developed a multifunctional cellulose-based film via a facile impregnation-curing strategy. Here, benzoxazine resin (BR) is used as an optically functional component to endow the microfibrillated cellulose (MFC) film with powerful light management capabilities including UV and blue light double shielding, high transmittance, and high haze. Meanwhile, the introduction of tannic acid (TA) substantially enhanced the mechanical properties of the film, including tensile strength and toughness, by constructing energy-sacrificial bonds. An effective self-healing of the film was achieved by controlling the degree of BR curing. The final films exhibited 98.24 % UV shielding and 89.98 % blue light blocking, good mechanical properties including a tensile strength of 202.21 MPa and tensile strain of 7.1 %, as well as desirable thermal healing properties supported by incompletely cured BR. This work may provide new insights into the high-value utilization of biomass resources.

Digitalization of Colorimetric Sensor Technologies for Food Safety

Colorimetric sensors play a crucial role in promoting on-site testing, enabling the detection and/or quantification of various analytes based on changes in color. These sensors offer several advantages, such as simplicity, cost-effectiveness, and visual readouts, making them suitable for a wide range of applications, including food safety and monitoring. A critical component in portable colorimetric sensors involves their integration with color models for effective analysis and interpretation of output signals. The most commonly used models include CIELAB (Commission Internationale de l'Eclairage), RGB (Red, Green, Blue), and HSV (Hue, Saturation, Value). This review outlines the use of color models via digitalization in sensing applications within the food safety and monitoring field. Additionally, challenges, future directions, and considerations are discussed, highlighting a significant gap in integrating a comparative analysis toward determining the color model that results in the highest sensor performance. The aim of this review is to underline the potential of this integration in mitigating the global impact of food spoilage and contamination on health and the economy, proposing a multidisciplinary approach to harness the full capabilities of colorimetric sensors in ensuring food safety.

Carrageenan-based functional films hybridized with carbon dots and anthocyanins from rose petals for smart food packaging applications

Multifunctional smart biopolymeric films were fabricated using rose petal anthocyanin (RPA) and carrageenan (CAR) doped with rose petal-derived carbon dots (RP-CDs). Response surface-optimized RPA showed the highest total anthocyanins and radical scavenging ability. Produced RP-CD exhibited UV absorption and high fluorescence with antibacterial/antioxidant abilities. Enrichment with 2 % RP-CD and 5 % RPA in the CAR matrix results in improved physicochemical, i.e., water contact angle, water vapor permeability, and UV-blocking properties of the fabricated material. Results showed that nanocomposite films scavenged radicals better than the neat CAR films. Zeta potential, FTIR, SEM, and XPS suggested improved compatibility/stability and enhanced elemental configuration of RP-CDs/RPA additives in the CAR polymer matrix. Perishable food packaging (minced pork and shrimp) demonstrated that nanocomposite films work efficiently and non-destructively and are promising tools for monitoring real-time freshness through interpretable visual changes from red to yellow. The CAR/RP-CDs/RPA-based nanocomposite indicator films are expected to be applied as various smart packaging materials. These films possess the ability to promptly detect changes in quality, preserve the quality, and prolong the shelf life of packaged foods.

Coconut husk-lignin derived carbon dots incorporated carrageenan based functional film for intelligent food packaging

Carbon dots (CDs) derived from sustainable natural feed-stocks like lignin have gained wide acceptance by virtue of their renewability and promising potential in intelligent sensing applications. The precursor lignin is isolated from agro-biomass waste, coconut husk through sodium hydroxide based extraction process. CDs are synthesised from amine functionalized lignin through solvothermal process and integrated into carrageenan biopolymer matrix (1, 2 and 3 wt%). The composite film with 2 wt% CDs (CARR2CD) showed optimum fluorescent emission intensity, excellent pH dependent fluorescent color change in the food pH range, reasonable tensile strength (46.50 ± 1.32 MPa) and 27 % increase in elongation at break. CDs imparted UV-light blocking properties (70 % UV-light) and enhanced hydrophobicity of the carrageenan matrix. CARR2CD film showed 84 % visible light transparency, 79 % reduction in oxygen transmittance rate (OTR), 81 % reduction in CO2 gas permeability and excellent antioxidant and antibacterial properties (against E. coli and S. aureus). As a practical application, the developed responsive packaging material is used to track pH change associated with milk spoilage via noticeable color change in fluorescent emission of the composite film. Thus, the developed responsive composite film paves a way for use as green and sustainable transparent intelligent food packaging material.