Antimicrobial Packaging Research Articles

Application of antimicrobial packaging based on modified calcium carbonate and EOs for RTE meat products

Highly porous modified calcium carbonate (MCC) powder has been successfully integrated into packaging material as a coating and the coated packaging films were loaded with 5, 10 or 30 wt % thyme and rosemary essential oil (EO). Resulting MCC labels were applied as labels and showed antimicrobial activities against L. innocua in in vitro test. After 6 days MCC labels with 10 and 30 wt % thyme EO showed significant reductions in in vitro tests (2.9 and > 8.5 log CFU/filter). When MCC labels with rosemary EO were used, only 30 wt % loading showed a significant reduction (1.6 log CFU/filter). Subsequently, the antimicrobial activity of MCC labels with 30 wt % EOs against L. innocua on ready to eat meat product were studied under normal atmosphere and modified atmosphere (MA). Use of MCC labels with 30 wt % thyme EO loading combined with MA packaging showed a significant microbial reduction of 1.2 log CFU/g on cooked ham after 21 days (compared to untreated MCC labels packaged under MA). On the other hand, use of MCC labels loaded with 30 wt % rosemary EO (with MA) showed significant reductions of L. innocua on sliced cooked chicken breast (2.6 log CFU/g) as well as cooked ham (1.3 log CFU/g).

Improved properties of gelatin films involving transglutaminase cross-linking and ethanol dehydration: The self-assembly role of chitosan and montmorillonite

In this study, the chitosan and montmorillonite (MMT) were synergistically introduced to improve the properties of the gelatin films through self-assembly. The preparation of gelatin films (G), gelatin + MMT composite films (G + MMT), gelatin-chitosan bilayer films (G-CS), and gelatin + MMT-chitosan composite bilayer films (G + MMT-CS) involved transglutaminase (TG) cross-linking followed by ethanol precipitation and self-assembly process. The water contact angle of the composite bilayer films (G-CS and G + MMT-CS) was higher than 110° due to the formation of surface hydrophobic layer formed by self-assembly via hydrogen bonding and electrostatic interaction between gelatin and chitosan, but the MMT alone cannot improve the hydrophobicity of gelatin films. The water solubility (WS) of G + MMT, G-CS and G + MMT-CS films was significantly lower than that of G films. The mechanical and barrier properties were significantly improved due to the introduction of MMT and the surface deposition of chitosan, attributing to the increase of triple helix content and formation of bilayer structure, respectively. Moreover, MMT caused the decrease of sterilization thermal shrinkage from 49.54% to 34.00%. Interestingly, MMT facilitated the surface deposition of chitosan during self-assembly process. The mold growth of bread wrapped with G + MMT-CS was effectively inhibited during storage, implying potential application as antimicrobial food packaging materials. • Self-assembly of gelatin and chitosan improved hydrophobicity of gelatin (G) films. • Chitosan and montmorillonite improved mechanical and barrier properties of G films. • Sterilization thermal shrinkage of G films was reduced by montmorillonite. • Introducing montmorillonite facilitated the self-assembly deposition of chitosan.

Impact of tea tree essential oil and citric acid/choline chloride on physical, structural and antibacterial properties of chitosan-based films

The purpose of this study was to develop a novel antimicrobial packaging film by using chitosan (CS), deep eutectic solvent (DES, a plasticizer) and tea tree essential oil (TTO, a natural antibacterial agent). The physical properties of the films (i.e., water content, solubility, water vapor permeability, color, thickness, water contact angle, and mechanical properties) demonstrated that TTO reduced the hydrophilicity of the films. At the same time, DES significantly improved the flexibility of the films. Micro-structural characterization showed that DES and TTO interacted with the CS matrix and were uniformly dispersed in films. The interactions among these main components in the films were verified by Fourier transform infrared spectroscopy and X-ray diffraction analysis. Thermogravimetric analysis further confirmed that these films had good thermal stability. In addition, the antibacterial assays verified that the CS-DES-TTO films could inhibit the activity of planktonic Sh. flexneri . The films prepared in this study showed the characteristics required of active packaging materials. • Chitosan, DES and TTO are uniformly distributed in the polymer matrix. • DES improved the mechanical properties of the film. • TTO improved the hydrophobicity of the film. • CS-DES-TTO films could damaged the cell membrane of Sh. flexneri.

Hydrophilic Composites of Chitosan with Almond Gum: Characterization and Mechanical, and Antimicrobial Activity for Compostable Food Packaging.

To enhance the characteristics of the biocomposite film, solution cast was used to incorporate almond gum at different concentrations (10.0, 30.0, and 50.0%). The functional groups and morphology were determined using FTIR and SEM. The thermal property of chitosan and its composites materials were determined via TGA. In this study, the incorporation of almond gum into the chitosan matrix resulted in good mechanical strength, film thickness, and low barrier and solubility characteristics. Water vapor transmission rate (WVTR) and oxygen transmission rate (OTR) of the composites films was also investigated. The WVTR and OTR values for the chitosan/almond gum (CSA) composite film values are 11.6 ± 1.62 (g/m2/day) and 32.9 ± 1.95(cc/m2/24 h),respectively. The obtained composites show significantly improved antimicrobial activity against Gram-negative (E. coli) and Gram-positive (S. aureus) food-borne pathogenic bacteria. The results suggest that the CSA composites may serve as a promising candidate for antimicrobial food packaging materials. After an observation of the test results, it is inferred that the CSA composites bear good mechanical and antimicrobial activity and also show enhanced morphological characteristics.

Electrospun eugenol-loaded gelatin nanofibers as bioactive packaging materials to preserve quality characteristics of beef

In this study, electrospinning technique was employed to fabricate eugenol loaded gelatin nanofibers (ELGNs) by using gelatin as an active material to encapsulate eugenol. The results indicated that eugenol could be successfully encapsulated within nanofibers, as verified by SEM, FTIR, and zeta potential analyses. The average zeta potential value of ELGNs was determined to be − 15.08 mV. The average diameter of gelatin nanofibers was enlarged with eugenol encapsulation, increasing to diameter of 125 nm. ELGNs had a smooth and uniform fiber morphology observed by SEM. The ELGNs demonstrated a potent antibacterial activity by significant (P < 0.05) reduction in the number of total mesophilic aerobic bacteria counts by 1.62 log and psychrophilic aerobic bacteria counts by 1.33 log in fresh beef samples treated with ELGNs. Moreover, the bioactive ELGNs maintained textural properties (hardness–4.75 N, gumminess–1.75 N, and chewiness–3.87 N × mm at 9th day of storage) and sensory properties, exhibiting advantages as antimicrobial packaging materials that maintained the quality and freshness of the raw meat, along with the extension of its shelf life to 9 days. Significant (P < 0.05; 0.01) negative and positive correlations were found among the microbiological, textural, and sensory parameters, which explained and confirmed the reason for the effectiveness of the nanofiber treatment. In conclusion, our results suggested that the electrospinning approach in this study could be an effective technique to encapsulate eugenol within gelatin nanofibers and the electrospun ELGN mats could be a novel bio-degradable active packaging material with good antibacterial effects.

Azadirachta indica leaf extract mediated silver nanoparticles impregnated nano composite film (AgNP/MCC/starch/whey protein) for food packaging applications

In order to be used in food packaging, the study aims to develop a composite film based on microcrystalline cellulose (MCC) and coated with silver nanoparticles (AgNPs). The MCC was derived from sugar cane bagasse. Protein, starch, and poly-ethylene glycol 1500 (PEG-1500) are employed to improve the tensile strength, flexibility, and durability of the packaging film. The AgNPs was synthesized by a green route employing Azadirachtaindica leaf extract as reducing agent. The determined average crystallite size of AgNPs was seen at 20 nm. The X-ray diffraction (XRD) studies of the final film prepared have an elevated peak with a crystallinity of 37.5%. The scanning electron microscopic images (SEM) of the AgNPs and the prepared samples, reveal their surface morphology. The Fourier transform infrared spectroscopic studies (FT-IR) disclose the functional group changes during the film preparation. The antibacterial activity of the amalgamated AgNPs against five bacterial pathogens studied was found to be highly active against tested food pathogens, except for Proteus vulgari. When coated over a vegetable, the produced nanocomposite film displayed an increased shelf life for the vegetable by limiting the decay impact caused by food pathogens. According to the findings, the AgNPs-impregnated MCC/Starch/Whey protein has the potential to be employed as an antimicrobial packaging material.

Influence of Quaternary Ammonium Salt Functionalized Chitosan Additive as Sustainable Filler for High-Density Polyethylene Composites.

In this study, an antimicrobial packaging material was successfully developed with blends of high-density polyethylene (HDPE) and chitosan (CS) made by melt processing. In the different HDPE/CS composites, the CS content effect (up to 40%), and the addition of quaternary ammonium salt functionalized chitosan (CS-CTAB) as an additive were evaluated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analyses (TG), tensile strength, scanning electron microscopy (SEM) and antimicrobial activity. When analyzing the effect of the additive in the different HDPE/CS composites, it was observed that the compositions with 10 and 20 %wt of chitosan showed better elongation values (~13% and 10%) as well as a higher decomposition temperature at 20% mass loss (T20) varying from (321-332 °C and 302-312 °C), respectively, in relation to the other compositions, regardless of the type of additive used, it acted as an antimicrobial agent, promoting inhibition of microbial growth against the strains gram-positive and gram-negative used in this work, making the different HDPE/CS composites suitable candidates for use in food packaging.

Selective antimicrobial food packaging of composite poly(lactic acid) cobalt-citrate films

Food spoilage is a well-known subject in worldwide research, involving a plethora of approaches linked to physical and chemical processes. Poised to develop active antimicrobial packaging materials addressing the specific issue, a composite film was prepared from biocompatible-biodegradable poly(lactic acid) (PLA), incorporating a bioinorganic hybrid metal-organic Co(II)-citrate (Co-cit) complex. The fabricated PLA-(Co-cit) film retained its physicochemical profile as attested to through FT-IR, UV-Visible, SEM, DSC, TGA, nanofocus-confocal microscopy, weight variation, moisture, bending, and mechanical tests, thus justifying further investigation in antimicrobial potency biological experiments. Testing involved Gram-positive/Gram-negative bacteria, revealing a well-defined antimicrobial profile, with clear specificity toward Listeria monocytogenes, thereby asserting proof of concept on the design of such materials. Collectively, the work sets the stage for development of materials conforming to demands of active packaging and employing physicochemically well-defined hybrid metal-organic species, bearing bacteria-specific antimicrobial properties, ultimately contributing to the maintenance of integrity and extension of shelf-life for foods.

Incorporation of Thymus vulgaris essential oil and ethanolic extract of propolis improved the antibacterial, barrier and mechanical properties of corn starch-based films

The present study illustrates the influence of Thymus vulgaris essential oils (TEOs), ethanolic extract of propolis (EEP), and their combination on corn starch-based films as antimicrobial packaging materials using the casting method. The FTIR results exhibited no structural change in the composite films after incorporating TEOs and EEP. However, the color properties of composite films were significantly affected by the addition of TEOs and EEP. The addition of TEOs and EEP increased the elongation at break from 5.8 to 13.5 % when TEOs and EEP added together, but tensile strength and modulus of the composite films decreased. The water solubility (SW) of composite films was significantly reduced when TEOs were added in the range of 17.31 % to 16.12 %. Also, the swelling ratio (SR) of all composite films was lower compared to the control film. The incorporation of EEP and TEOs did not change the water vapor permeability (WVP) of composite films significantly. However, the addition of EEP and TEOs in corn-starch films exhibited a synergic effect against Escherichia coli and Listeria monocytogenes. The developed antimicrobial composite films can be utilized in food packaging applications.

Inhibitory effect of calcium phosphate-coated high-affinity liposomes on Staphylococcus aureus and its biofilms

The contamination of Staphylococcus aureus (S. aureus) and its biofilm poses a serious challenge to food safety. In this study, a high-affinity liposome coated with calcium phosphate was developed to provide a novel strategy for antibacterial packaging. Litsea cubeba essential oil (LC-EO)-loaded liposomes with various anionic surfactants including sodium deoxycholate (SDC), sodium dodecyl sulfate (SDS), and sodium dodecyl benzene sulfonate (SDBS) were first synthesized using a film-ultrasonic dispersion method, then an attempt was made to coat calcium phosphate (CaP) shell layers on the surface of different anionic liposomes using a sequential deposition method. Anionic liposomes synthesized with the addition of SDBS (SDBS/EO-Ls) were found to be effective precursors for the successful capping of CaP shells. The SDBS/EO-Ls coated with CaP shells (CaP/SDBS/EO-Ls) were then characterized, including physicochemical properties, stability, and antibacterial and anti-biofilm activities. Results showed that the particle size of SDBS/EO-Ls can be increased by about 40 nm after being coated with a CaP shell, and the Zeta potential value can be decreased by about 25 mV. At the same time, the CaP coating helped to prevent the leakage of essential oils during storage. The prepared CaP/SDBS/EO-Ls had a better inhibitory effect against S. aureus and biofilm due to their high affinity. Even when CaP/SDBS/EO-Ls were applied in two different food systems (smoked bean curd and beef), they still had a long-lasting antibacterial effect. The CaP/SDBS/EO-Ls developed in this study could be used to develop a novel antimicrobial packaging additive.

Research on preserving red flesh dragon fruit by antimicrobial packaging containing polyguanidin

The method of preserving dragon fruit with smart packaging films (improved in terms of water permeability and air permeability) to improve the microclimate in the packaging is evaluated as a suitable method for these condition facilities in Vietnam and gives the best efficiency. In this study, red flesh dragon fruit was packaged in antibacterial packaging film (LLDPE-G) made based on linear low-density polyethylene (LLDPE) combined with polyhexamethylene guanidine (PHMG). The objective of this study was to determine the effect of the ratio of LLDPE-G packaging film area/agricultural products’ mass (cm²/g), storage temperature (ºC) to oxygen and carbon dioxide balance in the package, and nutritional and sensory quality of red-flesh dragon fruit during storage. Experimental results showed that the packaging film area/fruit mass ratio is 2.00 cm²/g, and the appropriate storage temperature is 6ºC, corresponding to the equilibrium of the microclimate at 3.77% O2 gas concentration and 5.84% CO2concentration. After 20 days of storage, the natural weight loss reached 7.86%, the fruit still retained its characteristics (with index a 50.55), total soluble solids (TSS) reached 14.56oBrix, vitamin C content reached 9.72 mg/100 g. These indicators met the food hygiene and safety standards on microbiology according to regulations of good agricultural practices (GAP).

Synergistic effects of fresh garlic juice in cellulose based antimicrobial food packaging film

Development of cellulosic edible films and coatings enriched with garlic juice. • Novel cellulosic edible film enriched with fresh garlic juice was proposed. • The film was treated with glycerol and citric acid vapor to improve mechanical properties. • The films displayed excellent stretchability and optical clarity. • The films possessed excellent antifungal and antibacterial properties, thus retaining the food fresh. This article presented a novel food packaging film made from cellulose nanofibers (CNFs), raw garlic juice and glycerol. The film was made tough, strong, and barrier-resistant by treating the CNFs with glycerol and citric acid vapor, which performed as a plasticizer and cross-linking agent, respectively. Garlic juice was added as the antibacterial agent. The as-produced films exhibited 529, 47, and 59% higher extensibility, moisture resistance, and water vapor barrier, respectively than the pristine CNF film. The film also showed excellent antifungal and antibacterial resistance.

Development of Antimicrobial Cellulose Nanofiber-Based Films Activated with Nisin for Food Packaging Applications.

The cellulose nanofiber (CNF) is characterized by the nano-sized (fibers with a diameter between 5 and 20 nm and a length between 2 and 10 μm), flexible and cross-linked structure that confer enhanced mechanical and gas barrier properties to cellulosic fiber-based packaging materials. The purpose of this work was to develop an antimicrobial packaging film by direct mixing nisin with CNF, followed by coating it onto polyethylene (PE), polypropylene (PP), and polylactic acid (PLA) films. The antimicrobial effectiveness of CNF-Nis+PE, CNF-Nis+PP, and CNF-Nis+PLA was investigated both in vitro end in ex vivo tests. In the latter case, challenge test experiments were carried out to investigate the antimicrobial activity of the coupled films of CNF-Nisin+PLA to inhibit the growth of Listeria innocua 1770 during the storage of a meat product. The films were active against the indicator microorganisms Brochothrix thermosphacta and Listeria innocua in in vitro test. Moreover, a reduction in the Listeria population of about 1.3 log cycles was observed immediately after the contact (T0) of the active films with hamburgers. Moreover, when the hamburgers were stored in active films, a further reduction of the Listeria population of about 1.4 log cycles was registered after 2 days of storage. After this time, even though an increase in Listeria load was observed, the trend of the Listeria population in hamburgers packed with active films was maintained significantly lower than the meat samples packed with control films during the whole storage period.

Bioactive Edible Sodium Alginate Films Incorporated with Tannic Acid as Antimicrobial and Antioxidative Food Packaging.

Currently, biodegradable and functional food packaging materials have attracted more and more attention due to their potential advantages. Biopolymers are one of the promising materials used to produce biodegradable food packaging films, and sodium alginate (SA) is one of the most used polysaccharides. In this work, we explored a novel edible sodium alginate (SA)/tannic acid (TA) film as biodegradable active food packaging material. The impact of TA concentration on the UV light blocking ability, transparency, water vapor barrier ability, mechanical strength, antioxidant, and antimicrobial activity of the SA-TA films was comprehensively investigated. Fourier transform infrared spectroscopy results revealed that strong hydrogen bonding was the main intermolecular interaction between SA and TA. As TA concentration in the films increased, the water vapor permeability (WVP) decreased from 1.24 × 10−6 to 0.54 × 10−6 g/m/h/Pa, the DPPH radical scavenging activity increased from 0.008% to 89.02%. Moreover, the incorporation of TA effectively blocked UV light and elevated antimicrobial activity against Escherichia coli. Overall, the SA films with TA exhibited better water vapor barrier ability, remarkable UV-light barrier ability and antioxidant activity while showing a slight decrease in light transmittance. These results indicated the potential application of TA as a functional additive agent for developing multifunctional food packaging materials.

Antibacterial, Antifungal and Antiviral Polymeric Food Packaging in Post-COVID-19 Era.

Consumers are now more concerned about food safety and hygiene following the COVID-19 pandemic. Antimicrobial packaging has attracted increased interest by reducing contamination of food surfaces to deliver quality and safe food while maintaining shelf life. Active packaging materials to reduce contamination or inhibit viral activity in packaged foods and on packaging surfaces are mostly prepared using solvent casting, but very few materials demonstrate antiviral activity on foods of animal origin, which are important in the human diet. Incorporation of silver nanoparticles, essential oils and natural plant extracts as antimicrobial agents in/on polymeric matrices provides improved antifungal, antibacterial and antiviral properties. This paper reviews recent developments in antifungal, antibacterial and antiviral packaging incorporating natural or synthetic compounds using preparation methods including extrusion, solvent casting and surface modification treatment for surface coating and their applications in several foods (i.e., bakery products, fruits and vegetables, meat and meat products, fish and seafood and milk and dairy foods). Findings showed that antimicrobial material as films, coated films, coating and pouches exhibited efficient antimicrobial activity in vitro but lower activity in real food systems. Antimicrobial activity depends on (i) polar or non-polar food components, (ii) interactions between antimicrobial compounds and the polymer materials and (iii) interactions between environmental conditions and active films (i.e., relative humidity, oxygen and water vapor permeability and temperature) that impact the migration or diffusion of active compounds in foods. Knowledge gained from the plethora of existing studies on antimicrobial polymers can be effectively utilized to develop multifunctional antimicrobial materials that can protect food products and packaging surfaces from SARS-CoV-2 contamination.

Antimicrobial and controlled release properties of nanocomposite film containing thymol and carvacrol loaded UiO-66-NH2 for active food packaging

In this work, Zirconium-based metal–organic frameworks (MOFs), UiO-66-NH2, were designed as loading carriers for thymol and carvacrol and added into chitosan to construct antimicrobial packaging films. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA) were applied to characterize the films. Besides, we analyzed the physical properties, mechanical performance, hydrophobicity, release behavior, and antimicrobial capacity of the films. It can be clearly seen that the addition of thymol and carvacrol loaded MOFs into chitosan film significantly improved the thermal stability, light barrier properties, tensile strength, and hydrophobicity. Importantly, UiO-66-NH2 restrained the release rate of thymol and carvacrol compared with pure chitosan film, which endowed efficient antimicrobial capacity against E. coli, S. aureus, and P. citrinum to chitosan films. Overall, the strategy conceived here can be a superior candidate to develop a premium antimicrobial material for active food packaging, which has potential application prospects.

Cellulose-based films reinforced by in-situ generated ZnO for antimicrobial packaging

Cellulose-based films reinforced by in-situ generated ZnO for antimicrobial packaging

Application of yellow mustard mucilage and starch in nanoencapsulation of thymol and carvacrol by emulsion electrospray

Starch/water soluble yellow mustard mucilage nanocapsules loaded with thymol and carvacrol (TC) were developed using electrospray atomization. Emulsions were electrosprayed, aiming to generate nanocapsules with a controlled release behavior of TC for antimicrobial packaging applications. To understand the effect of water soluble yellow mustard mucilage (WSM) on the nanocapsules, the emulsion viscosity, morphology, encapsulation efficiency, molecular interactions, and release kinetics were evaluated. Surface and internal morphological analysis revealed that nanocapsules were non-porous with minimal surface shrinkages and had inner multicore spheres within a solid wall layer. Encapsulation efficiency ranged from 61.17 to 84.10 %, increasing at higher TC contents. Fourier transform spectroscopy confirmed the molecular interaction between wall materials. The release kinetics of encapsulated TC (30 % w/w) followed a Fickian diffusion mechanism and a controlled release pattern up to 120 h. Results indicated that the addition of WSM can modulate the release kinetics of bioactives and achieve a controlled release pattern.

Self-assembly of colloidal lignin nanosphere particles blended with chitosan composite coated bagasse paper: An eco-friendly food packaging with antimicrobial properties

Chitosan/lignin nanocomposites were coated on bagasse paper surface to improve antimicrobial packaging. A commercial softwood kraft lignin was selected and purified by fractionation process using organic solvent. The aliphatic, phenolic and carboxylic hydroxyl groups of commercial softwood lignin and fractionated lignin were investigated using 31P NMR spectroscopy. For lignin nanosphere particles (LNPs) preparation, the fractionated lignin was dissolved in organic solvent (acetone), then the deionized water was added under ultrasonic mixing. The size of LNPs were approximately 40–500 nm. Chitosan solutions were mixed with 6–33 wt% of LNPs. The mixture was then spread over the bagasse paper surface. The papers coated with chitosan/LNPs were dehydrated at 40 °C for 48 h. For food packaging applications, the antibacterial activity of the paper packaging coated with chitosan/LNPs was more successful and effective against gram-positive bacteria (such as Staphylococcus aureus, S. aureus) and gram-negative bacteria (such as Escherichia coli, E. coli) compared with the bagasse paper without any coating. The antimicrobial activity of all papers coated with chitosan/LNPs for S. aureus and E. coli was above 2 log CFU/cm2 which are acceptable for antimicrobial efficacy and the percent reduction of bacteria was nearly 100%. In addition, this evident of chitosan/LNPs nanocomposites showed a synergistic effect enhancing the antimicrobial efficiency on the paper surface. The morphology, wettability and overall migration of paper coated with chitosan/LNPs samples were also explored.

Role of Active Packaging in the Food Industry: A Review

In response to shifting consumer demands, food packaging's conventional function is continuing to change. Consumer desire for healthier, safer and good quality meals with longer shelf-life is one of the current causes that are challenging the food packaging sector to produce new and better technology packaging solutions. Therefore, Active packaging (AP) can be used to satisfy these requirements. The biggest advantage of Active packaging (AP) is less food waste because the items have a longer shelf life. Undoubtedly, active packaging is a great option for a variety of food sector applications. In the upcoming years, the commercial success of active packaging systems should be anticipated as they represent the growth of food packaging in the future. In this review, a summary of active packaging technologies, including oxygen scavenger, moisture scavenger, ethylene absorber, antioxidant-releaser, CO2 emitter, and antimicrobial packaging systems are provided. In particular, reviews of scientific studies emphasizing the advantages of these technologies for certain food products are conducted. However, the development of food nano-packaging is still in its early stage, despite having numerous opportunities to enhance packaging materials and functions. Although, due to the advancements in nanotechnology there might be higher chances of enabling the creation of better active packaging. This article also discusses current breakthroughs in food nano packaging based on active nanoparticles.