Antimicrobial Packaging Materials Research Articles

Electrospun cellulose acetate and poly(vinyl chloride) nanofiber mats containing silver nanoparticles for antifungi packaging

Nanofiber mats of poly(vinyl chloride) (PVC) and cellulose acetate (CA) encapsulated with silver (Ag) nanoparticles were fabricated via electrospinning for potential use as antimicrobial food packaging materials. 16 wt% PVC was prepared in 1:1 w/w tetrahydrofuran—N,N-dimethylformamide while 16 wt% CA was prepared in 3:2 (w/w) Acetone—N,N-dimethylformamide. Scanning electron microscopy analysis showed that thinner fibers could be electrospun from cellulose acetate as compared to poly(vinyl chloride) at the same solution concentrations with fiber diameters ranging from 70 to 130 nm for cellulose acetate and 180–340 nm for poly(vinyl chloride). Nanofiber diameter reduced with addition and increase of silver nanoparticles from 0 to 1 wt%. Due to the smaller cellulose acetate nanofiber diameter, its mats had lower air permeability rates. Tensile strength tests indicated that the nanofiber mats had marginal to good tensile strength values relative to film based packaging materials. Antimicrobial examination of the nanofiber mats against yeast and mould indicated that there was inhibited growth of the microorganisms on mats containing silver nanoparticles.

Development of antimicrobial gelatin films with boron derivatives.

Food packaging technology has been advancing to provide safe and high quality food products and to minimize food waste. Moreover, there is a dire need to replace plastic materials in order to reduce environmental pollution. The aim of this study was to prepare biodegradable antimicrobial packaging films from gelatin. Boric acid, disodium octaborate tetrahydrate, and sodium pentaborate were incorporated as the antimicrobial agents. Films containing boric acid and its salts showed antibacterial effect against Staphylococcus aureus and Pseudomonas aeruginosa, as well as antifungal and anticandidal effects against Aspergillus niger and Candida albicans. The mechanical strength of the films was mostly enhanced by the addition of boron derivatives. The rheological measurements and Fourier-transform infrared spectroscopy results suggest that boron derivatives did not interfere with the network formation during gelling. The morphology of boron-added antimicrobial films was found to be similar to the morphology of the control . In conclusion, the newly developed gelatin films containing 10% or 15% disodium octaborate (g/g gelatin) might be good candidates for biodegradable antimicrobial packaging materials.

Increasing the quality and impact of manuscripts in the field of new materials

Increasing the quality and impact of manuscripts in the field of new materials

Development and characterization of biodegradable antimicrobial packaging films based on polycaprolactone, starch and pomegranate rind hybrids

Abstract Polycaprolactone (PCL)/starch/pomegranate rind (PR) hybrids were developed for antimicrobial packaging applications. PR was used, for the first time, as an antimicrobial compound and was incorporated directly in PCL matrix, without the extraction of any active compound from the fruit rind. The PCL-based antimicrobial films were fabricated using extrusion technique. It was observed that PCL/PR films demonstrated reasonably good antimicrobial activity at higher concentration of active compound. Addition of starch not only lowered the cost but also improved the rigidity of PCL matrix. Adding to this, starch enhanced the antimicrobial activity of PR, and provided a releasing channel for the delivery of polyphenols by attenuating the interactions between PCL and PR. Since all the materials used in this work are biodegradable and food contactable, it is expected that the developed material can be employed as food-grade antimicrobial packaging material.

Release of essential oil constituent from thermoplastic starch/layered silicate bionanocomposite film as a potential active packaging material

In this present work, we study the release of essential oil constituents from thermoplastic starch/layered silicate (TPS/LS) bionanocomposite films used as antimicrobial proposed as a potential antimicrobial packaging material. A comprehensive application of design of experiments and multivariate calibration was used in order to study bionanocomposite formulation parameters that influence the release profile of carvacrol (CRV). Three formulation parameters (type of nanoclay, concentration of nanoclay and concentration of plasticizer) were simultaneously calibrated with three experimental responses (mechanical properties, thermal stability, and CRV release profile) by using D-optimal design and partial least squares (PLS) regression. The validated PLS model (R2 = 0.9272) showed that packaging properties as Young’s modulus and thermal resistance are positively correlated with concentration of nanoclay and negatively correlated with concentration of plasticizer in the formulation due to an increase in the intercalated/exfoliated structures, which was corroborated by XRD and TEM images. CRV release is controlled by complexes interactions among these formulation variables. Higher amount of nanoclay is correlated with higher intercalation/exfoliation due to the formation of intricate structure of the matrix that could hinder the migration of CRV by formation of tortuous pathways that increase CRV half-life (θ1/2). Also, non-polar interaction between CRV and the hydrocarbon chains of nanoclay organomodifiers increases θ1/2. Thus, by knowing the formulation characteristics of this packaging material it is possible to predict the release of the active compound, so this could provide information that allows to design an efficient active packaging material with optimal antimicrobial release profiles according its use.

Starch-gelatin antimicrobial packaging materials to extend the shelf life of chicken breast fillets

Antimicrobial starch:gelatin (1:1) films containing N-α-lauroyl-l-arginine ethyl ester monohydrochloride (LAE) (10 % wt.) were used as food contact active layers in chicken breast fillets vacuum-packaged in polyamide/polyethylene pouches. Active layers were thermoprocessed (TP) or cast (OC) on the plastic film. Oxidized starch was used in OC coatings. Packaged chicken breast samples were stored at 4 °C and their physicochemical properties (pH, colour and lipid oxidation) and microbial quality were analysed throughout storage. Both TP and OC films significantly (p < 0.05) extended the shelf life of chicken breast fillets compared to control samples. The starch oxidation reaction in OC films promoted the formation of Maillard reaction compounds in the starch-gelatine blends, which enhanced the antimicrobial effectiveness of the OC films, but also promoted oxidative processes. This greatly affected the pH and colour parameters in OC packaged samples. Therefore, TP blend films containing LAE are recommended since they effectively extended the shelf life of chicken breast fillets without affecting the meat oxidation.

A Comprehensive Review on Antimicrobial Packaging and its Use in Food Packaging

The recent food-borne microbial outbreaks in the world have led to the search for more innovative ways to inhibit microbial growth in foods that will maintain their quality, freshness, and safety. One of the options, that provides an increased margin of safety and quality in food products is the use of antimicrobial packaging. The next generation of food packaging may include materials with antimicrobial properties. These packaging technologies could play a role in extending the shelf-life of foods and reduce the risk from pathogens. Antimicrobial packaging is a form of active packaging which interacts with the product or the headspace between the package and the food system, to obtain a desired outcome. Antimicrobial packaging has an important effect on food packaging when the shelf-life extension and food safety of food products are taken into consideration. The basic idea behind this technology is the usage of antimicrobial substances in polymeric matrices to target specific microorganisms, in order to achieve higher safety and quality food products with extended shelf life. Various types of antimicrobial substances such as organic acids and their salts, enzymes, bacteriocins, and miscellaneous compounds (triclosan, silver, and fungicides) have been used in synthetic polymers and edible films. Different types of antimicrobial food packaging systems can be constructed by using antimicrobial packaging materials and/or antimicrobial agents inside the package space or inside foods.

Nisin and other antimicrobial peptides: Production, mechanisms of action, and application in active food packaging

Antimicrobial peptides are protein fragments present in the innate immune systems of invertebrates and vertebrates as host defense molecules. Due to their unique properties, these compounds have several useful appliances in human health by potentially playing antibacterial, antiviral, antifungal, and antitumor roles. The incorporation of antimicrobial peptides into polymer matrices as delivery systems has been studied recently with further interest towards the fields of medicine, pharmacy, personal care, and food packaging. The consumers' tendency to demand more natural products has paved the route for food industries to explore novel mechanisms as food preservation techniques. Antimicrobial peptide-containing active packaging materials emerge as a promising approach to retard food spoilage and increase food safety and shelf life. This text presents a comprehensive review of antimicrobial peptides, from synthesis procedures to mechanisms of action, with an emphasis on nisin. A historical outlook and the current perspectives of their potential applications in food packaging systems are also addressed.

Synthesis of monodisperse chitosan nanoparticles

The objectives of this study were to evaluate the effects of the initial concentrations of chitosan (CS) and sodium tripolyphosphate (TPP), the CS:TPP mass ratio, the CS molecular weight (MW) and pH on the synthesis of CS nanoparticles (CS NPs). The particle size of the synthesised CS NPs was significantly affected (P < 0.05) by these parameters. Self-assembled monodisperse CS NPs with a particle size of 90 nm and zeta potential of 30.15 mV were successfully synthesised using solutions of 0.1% low MW CS at pH 4.6 and 3:1 (CS:TPP) mass ratio. When higher concentrations of CS were used, application of external forces (tip sonication or Ultra-Turrax™) was necessary to induce monodispersity and significantly (P < 0.05) reduce the particle size; however, the particle sizes were >300 nm. While both native CS and CS NPs showed antimicrobial activity, no significant antimicrobial enhancement was observed for the NP form. The findings of this study have shown that monodisperse CS NPs can be obtained using a combination of bottom-up and top-down techniques and the unique physiochemical properties of these nanomaterials have the potential for applications in developing of antimicrobial active packaging materials.

Preparation and characterization of hybrid cationic hydroxyethyl cellulose/sodium alginate polyelectrolyte antimicrobial films

This study aimed to develop polyelectrolyte‐structured antimicrobial food packaging materials that do not contain any antimicrobial agents. Cationic hydroxyethyl cellulose was synthesized and characterized by Fourier‐transform infrared, 1H NMR, and 13C NMR spectroscopy. Its nitrogen content was determined by Kjeldahl method. Polyelectrolyte‐structured antimicrobial food packaging materials were prepared using hydroxyethyl cellulose, cationic hydroxyethyl cellulose, and sodium alginate. Antimicrobial activity of materials was defined by inhibition zone method (disc diffusion method). Thermal stability of samples was evaluated by thermal gravimetric analysis and differential scanning calorimetry. Surface morphology of samples was investigated by SEM. The obtained results prove that produced food packaging materials have good thermal and antimicrobial properties, and they can be used as food packaging material in many industries.

Combined Effect of Ultrasound Stimulations and Autoclaving on the Enhancement of Antibacterial Activity of ZnO and SiO₂/ZnO Nanoparticles.

This study investigates the antibacterial activity (ABA) of suspensions of pure ZnO nanoparticles (ZnO-NPs) and mesoporous silica doped with ZnO (ZnO-UVM7), as well as electrospun nanofibers containing those nanoparticles. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these two materials were also determined under the same conditions. The results showed a concentration-dependent effect of antibacterial nanoparticles on the viability of Escherichia coli (E. coli). Moreover, the combination of the stimulations and sterilization considerably enhanced the antimicrobial activity (AMA) of the ZnO suspensions. Poly (lactic acid) (PLA) solutions in 2,2,2-trifluoroethanol (TFE) were mixed with different contents of nanoparticles and spun into nonwoven mats by the electrospinning process. The morphology of the mats was analyzed by scanning electron microscopy (SEM). The amount of nanoparticles contained in the mats was determined by thermogravimetric analysis (TGA). The obtained PLA-based mats showed a fibrous morphology, with an average diameter ranging from 350 to 450 nm, a porosity above 85%, but with the nanoparticles agglomeration on their surface. TGA analysis showed that the loss of ZnO-NPs increased with the increase of ZnO-NPs content in the PLA solutions and reached 79% for 1 wt % of ZnO-NPs, which was mainly due to the aggregation of nanoparticles in solution. The ABA of the obtained PLA mats was evaluated by the dynamic method according to the ASTM standard E2149. The results showed that, above an optimal concentration, the nanoparticle agglomeration reduced the antimicrobial efficiency of PLA mats. These mats have potential features for use as antimicrobial food packaging material.

Application of an antimicrobial packaging material from chicken bone gelatine and cinnamon bark oil to mozzarella cheese

SummaryChicken bones are mostly discarded even though they contain a considerable amount of proteins, which would allow them to be applicable as a protein film source. In this study, chicken bone gelatine (CBG) films were prepared and characterised after the addition of cinnamon bark oil (CBO) to confer antimicrobial activity. The incorporation of 1% CBO increased the tensile strength of the CBG film from 18.2 to 23.9 MPa, whereas elongation at break was decreased from 15.6% to 5.91% and water solubility from 88.9% to 62.2%. Antimicrobial activity of the CBG films against foodborne pathogens as well as their antioxidant activity increased with the increase in CBO concentration. When CBG film containing 1% CBO was used for wrapping mozzarella cheese inoculated with Listeria monocytogenes, the population of the bacterium decreased after 20 days in storage, indicating that CBG films can be applied for improving the microbiological safety of mozzarella cheese.

Antimicrobial and biodegradable food packaging applications of polycaprolactone/organo nanoclay/chitosan polymeric composite films

Biodegradable and antimicrobial polymeric food packaging materials are very important because of environmental problems, for quality, and the shelf life of the product. The aim of this paper is to produce antimicrobial and biodegradable food packaging films with polycaprolactone (PCL). Using the amount of PCL (w/w) as the basis and to control the degradation time and to give antimicrobial properties, 0.4 wt% of organo nano clay (C) and 25, 50, and 75 wt% chitosan (K), and the use of glycerol monooleate (GMO) or oleic acid (OA) as a plastifier (5, 10, 20, and 30 wt%) are added and 12 polymeric composite films were prepared. The samples were coded as PCL (P), organo nanoclay (C), oleic acid (O), and glycerol monooleate (G). For example, P_C0.4_G5 refers to the PCL composite film containing 0.4 wt% clay and 5 wt% glycerol monooleate (G). The disc diffusion procedure with Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, and Candida albicans test microorganisms were used to evaluate the antimicrobial properties of the films. PCL_C0.4_O5, PCL_C0.4_G5, PCL_C0.4_G10_K25, PCL_C0.4_O10_K25, and PCL_C0.4_O20_K50 and neat chitosan films have antimicrobial properties. A small amount of organo nano clay, 0.4 wt%, has an antimicrobial effect on C. albicans. The PCL_C0.4_G10_K25 composite film has an antimicrobial effect on E. coli, P. aeruginosa, and C. albicans. Mechanical tests were performed, and it was observed that the mechanical properties of PCL composite films decrease with the addition of chitosan. J. VINYL ADDIT. TECHNOL., 24:376–387, 2018. © 2017 Society of Plastics Engineers

Shelf-life extension and quality attributes of sauced silver carp fillet: A comparison among direct addition, edible coating and biodegradable film

Nowadays, antimicrobial packaging materials is attracting remarkable attention as one of the preferred emerging technologies to prevent the development and spread of spoilage and pathogenic microorganisms via food foodstuffs. The aim of the present study was to incorporate Ziziphora clinopodioides essential oil (ZEO; 0 and 0.5%), apple peel extract (APE; 0 and 1%) and zinc oxide nanoparticle (ZnO; 0 and 0.5%) into sauced silver carp fillet using three techniques including direct addition, edible coating and composite film based on sodium alginate-carboxymethylcellulose (SA-CMC) to increase the shelf life (microbial, chemical and sensory properties) and inhibit the growth of Listeria monocytogenes during refrigerated storage over a period of two weeks. The fillet coated with ZEO 0.5% + APE 1% + ZnO 0.5% significantly exhibited the lowest bacterial population for the entire of storage period (P < 0.05). All treated samples tended to retard the increases in total volatile base nitrogen, trimethyl-amine nitrogen, pH and peroxide value. ZEO 0.5% + APE 1% + ZnO 0.5% and ZEO 0.5% + APE 1% showed the best sensory attributes (odor, color and overall acceptability). It can be concluded that the SA-CMC coatings or films enriched with ZEO 0.5% + APE 1% + ZnO 0.5% and ZEO 0.5% + APE 1% can be used as appropriate active packaging materials to preserve sauced silver carp fillets.

Effect of different packaging materials containing poly-[2-(tert-butylamino) methylstyrene] on the growth of spoilage and pathogenic bacteria on fresh meat

The objective of this study was to investigate the effect of novel antimicrobial packaging materials containing poly-[2-(tertbutylamino) methylstyrene] (poly(TBAMS)) on the growth of typical spoilage and pathogenic bacteria present on meat.The antimicrobial activity of materials containing different poly(TBAMS) concentrations was determined by comparing the bacterial counts on reference and sample materials at different temperatures and times and in the presence of meat components. Storage tests with poultry fillets and veal cutlets were conducted with samples vacuum packaged in the reference foil and foil containing 10% poly(TBAMS). After specific time intervals, typical spoilage microorganisms, total viable count (TVC), sensory changes and pH value were analysed.The results of the different poly(TBAMS) containing packaging materials showed an increase of the antimicrobial activity with an increasing amount of poly(TBAMS) in the base polymer. A high antimicrobial activity against inoculum of spoilage and pathogenic organisms typical for meat products was detected of a multilayer foil containing 10% poly(TBAMS) in the inner layer after 24h at 7°C. Gram positive-bacteria were more sensitive to poly(TBAMS) foil than gram-negative bacteria. In storage tests however, over the entire storage, a significant effect of this poly(TBAMS) foil on microbial growth on chicken breast fillets and veal cutlets could not be identified.Poly(TBAMS) packaging materials showed very good antimicrobial properties against a wide range of bacteria. However, for a significant inhibition of microbial growth on fresh meat, a higher amount of poly(TBAMS) was necessary to prolong the shelf life of meat.

A mathematical model for tailoring antimicrobial packaging material containing encapsulated volatile compounds

A mathematical model describing the water content-dependent release of an antimicrobial agent (allyl isothiocyanate (AITC)) from a bio-based film to the packaging headspace was implemented. The system was characterised experimentally by assessing release kinetics and diffusivities. The model was validated by comparing simulations to experimental data. In spite of the high complexity of the system coupling moisture and antimicrobial diffusion within the packaging material and then release into headspace, the presented model provides a good enough reproduction of experimental conditions. A sensitivity study conducted on the model showed that the release kinetics of the antimicrobial agent were the most influential parameters, and that the diffusivity of moisture and AITC within the film have negligible impact. The model was then used to demonstrate the efficiency of such packaging for shelf-life optimization as it successfully inhibited the growth of bacteria. This work provides a framework that can be used for decision support systems.

Antimicrobial agent-free hybrid cationic starch/sodium alginate polyelectrolyte films for food packaging materials

This study aimed to develop polyelectrolyte structured antimicrobial food packaging materials that do not contain any antimicrobial agents. Cationic starch was synthesized and characterized by FT-IR spectroscopy and 1H NMR spectroscopy. Its nitrogen content was determined by Kjeldahl method. Polyelectrolyte structured antimicrobial food packaging materials were prepared using starch, cationic starch and sodium alginate. Antimicrobial activity of materials was defined by inhibition zone method (disc diffusion method). Thermal stability of samples was evaluated by TGA and DSC. Hydrophobicity of samples was determined by contact angle measurements. Surface morphology of samples was investigated by SEM. Moreover, gel contents of samples were determined. The obtained results prove that produced food packaging materials have good thermal, antimicrobial and surface properties, and they can be used as food packaging material in many industries.

Antimicrobial effect of an Undaria pinnatifida composite film containing vanillin against Escherichia coli and its application in the packaging of smoked chicken breast

SummaryTo develop a value‐added product, we used the under‐utilised seaweed Undaria pinnatifida as a source material for the fabrication of a biodegradable film by extracting U. pinnatifida protein (UPP). UPP/gelatine composite films with different constituent ratios were prepared. In addition, the UPP/gelatine composite films containing vanillin (0.05%, 0.1% and 0.5%) were prepared as antimicrobial packaging material. To evaluate the utility of the UPP composite film containing 0.5% vanillin as food packaging material, smoked chicken breast samples inoculated with Escherichia coli were packed with the film and stored at 4 °C for 10 days. It was observed that packaging of smoked chicken breast with the UPP composite film containing vanillin decreased the population of the inoculated E. coli by 1.12 log CFU g−1 compared with that in the control sample. Thus, the UPP/gelatine composite film with added vanillin can be utilised as a packaging material for smoked chicken breast.

Application of a puffer fish skin gelatin film containing Moringa oleifera Lam. leaf extract to the packaging of Gouda cheese.

This study aims to develop a puffer fish skin gelatin (PSG) film that contains Moringa oleifera Lam. leaf extract (ME) as a new biodegradable film. With the increase in ME concentration, the tensile strength and elongation at break of the PSG film increased, whereas the oxygen permeability and water vapor permeability decreased. In addition, the PSG film with ME exhibited antimicrobial activity against Listeria monocytogenes and antioxidant activity. To apply the ME-containing PSG film to food packaging, Gouda cheese was wrapped with the ME-containing PSG film. During storage, the cheese packaging with the ME-containing PSG film effectively inhibited the microbial growth and retarded the lipid oxidation of cheese compared with the control sample. Thus, the ME-containing PSG film can be used as an antimicrobial and antioxidative packaging material to improve the quality of food products.

Raman spectroscopy, electronic microscopy and SPME-GC-MS to elucidate the mode of action of a new antimicrobial food packaging material.

One critical challenge when developing a new antimicrobial packaging material is to demonstrate the mode of action of the antimicrobials incorporated into the packaging. For this task, several analytical techniques as well as microbiology are required. In this work, the antimicrobial properties of benzyl isothiocyanate, allyl isothiocyanate and essential oils of cinnamon and oregano against several moulds and bacteria have been evaluated. Benzyl isothiocyanate showed the highest antimicrobial activity and it was selected for developing the new active packaging material. Scanning electron microscopy and Raman spectroscopy were successfully used to demonstrate the mode of action of benzyl isothiocyanate on Escherichia coli. Bacteria exhibited external modifications such as oval shape and the presence of septum surface, but they did not show any disruption or membrane damage. To provide data on the in vitro action of benzyl isothiocyanate and the presence of inhibition halos, the transfer mechanism to the cells was assessed using solid-phase microextraction-gas chromatography-mass spectrometry. Based on the transfer system, action mechanism and its stronger antimicrobial activity, benzyl isothiocyanate was incorporated to two kinds of antimicrobial labels. The labels were stable and active for 140days against two mould producers of ochratoxin A; Penicillium verrucosum is more sensitive than Aspergillus ochraceus. Details about the analytical techniques and the results obtained are shown and discussed. Graphical Abstract Antimicrobial evaluation of pure compounds, incorporation in the packaging and study for mode of action on S. coli by Raman, SEM and SPME-GC-MS.