Comprehensive Review on Significance and Advancements of Antimicrobial Agents in Biodegradable Food Packaging

Food packaging encloses food to defend it from tampering or contamination from physical, chemical, and biological sources. Active packaging is considered the most desirable system for retaining food products. Traditional food packaging serves containment and communication, protection and preservation, convenience, and marketing. Packaging must meet criteria including legislation and protection while being innovative, easy to apply, and attractive. A principal duty is guarding against chemical, mechanical, and microbiological impacts and maintaining freshness and nutritional value. Despite its importance, packaging is often viewed as wasteful and an environmental menace. A large quantity of food is wasted globally, with up to 25% of residential food waste attributed to packaging size or design. Packaging waste from non-biodegradable polymers forms a large part of municipal solid waste. PE and other petroleum-based polymers are resistant to biodegradation, causing contamination. To address this, biodegradable polymers from renewable resources are being developed. Biopolymers can replace non-biodegradable plastics, being compostable and environmentally friendly. Antimicrobial packaging prevents or eliminates pathogenic microorganisms in food and, combined with biodegradable materials, aligns with sustainability demands. The paper overviews ongoing research and technologies for next-generation intelligent, active packaging systems that sense changes in the package or environment. Incorporation of antibacterial nanoparticles, antifungals, and antioxidants into green polymers is a key trend. Challenges include controlling release of active ingredients from packaging to food to avoid sensory/toxicological issues, and ensuring appropriate contact to allow diffusion. Techniques include direct integration into polymer matrices, immobilization, and surface coating. Polymer-specific mass transport, permeability, sorption, and migration influence effectiveness. The review summarizes developments and uses of antimicrobial biodegradable films and nanotechnology-enabled bio-based packaging solutions, emphasizing consumer preferences for modern packaging that adds value and extends shelf life.

The review classifies antimicrobial agents and details their incorporation into biodegradable food packaging. It outlines antimicrobial packaging approaches: (1) materials enabling direct contact and migration of active ingredients to food (e.g., vacuum-sealed or wrapped foods), and (2) modified atmosphere packaging where antimicrobials are placed inside the package but not in direct contact. Active agents can be added into polymers, coated on surfaces, or incorporated into antimicrobial polymer films. Agents include organic acids and salts (e.g., sorbic, benzoic, acetic, propionic, ascorbic), enzymes (e.g., lysozyme), bacteriocins (e.g., nisin, natamycin), fungicides, plant extracts and essential oils (e.g., oregano, thyme, clove, cinnamon, basil), polyphenols, protein hydrolysates, ions, ethanol, and others. Natural antimicrobials are discussed from plant, animal, and microbial origins. Plant-based agents (essential oils and extracts rich in flavanols, terpenes, phenolic acids, tannins, stilbenes) can be embedded in biopolymer films (e.g., PLA, chitosan, starch) to extend shelf life and add antioxidant activity, though heat processing can reduce efficacy. Animal and microbe-derived agents include probiotics, bacteriocins, lactoferrin, lysozyme, chitosan, and marine-derived materials (e.g., sea cucumber components; lignin-based additives), with demonstrated activity against various bacteria, molds, and yeasts. Chemical antimicrobials (organic acids and their salts) act by disrupting membranes, intracellular pH, and metabolism; effectiveness depends on acid properties, food matrix buffering, target microorganism, and exposure time. The review compiles applications of antimicrobial packaging across foods (meats, cheeses, produce), including edible films and biodegradable matrices (agar, pullulan, carrageenan, alginate, cellulose acetate, soy protein, chitosan), and discusses nanocomposites (e.g., MMT clay, TiO2, Ag, Cu, ZnO). Nanotechnological interventions include green synthesis of nanoparticles using plant extracts, nanoencapsulation for controlled release and stability, and nanocellulose-based systems to enhance barrier and mechanical properties. Safety considerations are addressed: nanoparticle migration, size-dependent toxicity, potential genotoxicity/carcinogenicity, and impacts on gut microbiota; essential oils are generally safe at packaging-use levels but may affect beneficial microbes. The review also situates antimicrobial packaging within sustainability and circular economy goals, highlighting biodegradable, renewable materials and the need for regulatory alignment and consumer acceptance.

• Biopolymers (agar, pullulan, carrageenan, alginate, cellulose acetate, soy protein, chitosan) can host antimicrobial agents to form films/coatings that extend shelf life and enhance safety.
• Incorporation of nanoclays (e.g., MMT) reduces gas transmission, helping maintain freshness and extend shelf life of oxygen-sensitive foods.
• Gelatin-based and other biopolymer nanocomposite films with TiO2, Cu, Ag, and ZnO nanoparticles show strong antibacterial activity against foodborne pathogens.
• Plant essential oils and polyphenols in biodegradable films provide antimicrobial and antioxidant effects; examples include: • Ground beef shelf life extended by up to 12 days using PLA–nanocellulose composites infused with Mentha piperita or Bunium persicum essential oils. • Listeria-infected cheese preserved for 24 days using starch films infused with clove leaf oil; films also improved tensile properties, UV barrier, and radical scavenging. • PLA films with silver ions achieved a 4 log CFU reduction of Salmonella enterica on lettuce after 6 days at 4°C.
• Organic acids (e.g., sorbic, propionic, acetic, citric, malic) and salts exhibit broad antimicrobial action (e.g., sorbic acid against yeasts/molds; propionic acid against E. coli and Salmonella; malic acid against L. monocytogenes; potassium sorbate against bacteria and molds).
• Antimicrobial peptides/bacteriocins (e.g., nisin, natamycin) and enzymes (lysozyme) are effective in films/coatings against Gram-positive bacteria and spoilage organisms.
• Controlled-release strategies and polymer matrix tuning (permeability/sorption) are critical to maintain effective, safe antimicrobial concentrations over shelf life.
• Nanocellulose (CNC/CNF) enhances film strength and acts as a carrier for antimicrobials; generally low cytotoxicity, though potential microbiota effects are noted.
• Green nanotechnology approaches (plant-mediated nanoparticle synthesis, nanoencapsulation) can improve stability and release of natural antimicrobials while supporting sustainability goals.

The review demonstrates that integrating antimicrobial agents into biodegradable packaging addresses dual challenges: reducing food spoilage/borne illness and mitigating environmental impact from conventional plastics. Evidence across multiple food systems shows that natural extracts (essential oils, polyphenols), biopolymers (chitosan, pectin, alginate, PLA), and nanofillers (clays, metal/metal oxide nanoparticles, nanocellulose) can synergistically enhance antimicrobial efficacy, barrier properties, and mechanical performance, leading to measurable shelf-life extensions and pathogen reductions. Controlling release kinetics and ensuring polymer–agent compatibility are central to aligning antimicrobial activity with microbial growth dynamics during storage. The findings support active packaging as a viable hurdle in combination with traditional preservation (low temperature, modified atmosphere, pH control). At the same time, safety considerations (migration, nanoparticle toxicity, sensory impacts) and regulatory constraints limit immediate broad deployment. The review underscores the need for standardized evaluation of efficacy, migration, and safety to translate promising laboratory systems into commercially acceptable, consumer-trusted solutions.

Antimicrobial biodegradable packaging, leveraging natural bioactives (peptides, essential oils), nanoparticles, and biopolymers, can prevent undesirable changes in foods during storage and extend shelf life via controlled, sustained release at the food surface. Replacing non-compostable, oil-derived plastics with biodegradable matrices introduces new challenges (compatibility, stability, controlled release, processing losses) but offers environmental benefits and added functional performance. Future work should focus on: improving antimicrobial effectiveness and stability (e.g., via nanoencapsulation and matrix engineering), identifying potent natural antimicrobials, elucidating in vitro and in vivo performance, conducting comprehensive toxicology for nano-enabled systems, and establishing clear regulations and guidelines. Advances in design, manufacturing, and recycling will continue to expand the practicality and sustainability of antimicrobial packaging, supporting food safety and quality while reducing plastic pollution.

• Practical control of antimicrobial release rates from packaging into foods remains challenging; concentrations must avoid sensory and toxicological issues while maintaining efficacy.
• Limited commercial applications due to regulatory status of additives, lack of specific rules for active packaging, and uncertainty about consumer acceptance and economic impact.
• Natural antimicrobials (e.g., essential oils) can volatilize or degrade during high-temperature processing, reducing antibacterial effectiveness.
• Nanoparticle-enabled systems raise safety concerns: potential migration into food, size-dependent toxicity (greater toxicity at smaller sizes), possible genotoxicity/carcinogenicity, and impacts on gut microbiota; comprehensive toxicological assessments are needed before commercialization.
• Polymer–agent compatibility, mass transport/permeability, and processing constraints can limit performance and scalability of films.
• Many studies are laboratory-scale; more in vitro and in vivo studies and real-food validations are required to inform regulation and industry adoption.