Active Packaging Films Research Articles

Synthesis of responsive microcapsule (4H7MC-ECH-g-β-CD) and preparation of UV-responsive controlled-release packaging film

The synthesis of green UV-controlled release active packaging films using 4-hydroxy-7-methoxycoumarin as photosensitizing factor, β-cyclodextrin as main molecule and PLA-PVA as film-making base solution was reported. Firstly, 4-hydroxy-7-methoxycoumarin and β-cyclodextrin reacted to obtain 4H7MC-ECH-g-β-CD. 4H7MC-ECH-g-β-CD can undergo reversible photodimerization reaction at 365/256 nm in solid state. Then p-methoxybenzaldehyde/4H7MC-ECH-g-β-CD inclusion complex was prepared, investigated the loading capacity and found to be maximum at 40 ℃ and 3 h. Molecular docking proved that they formed stable inclusion complex. In the study of UV-controlled release of inclusion complex and film, it was found that the release rate of p-methoxybenzaldehyde was as follows: the release rate of samples irradiated with 365 nm < the release rate of samples irradiated with 256 nm < the release rate of samples without any treatment. This suggested that UV light can be used as a condition to control the release of p-methoxybenzaldehyde to regulate the release from inclusion complex and film.

PVA/essential oil‐based active food packaging films functionalised with halloysite nanotubes and cellulose nanocrystals as filler materials for the shelf‐life extension of papaya fruits

SummaryThis study investigates the development of polyvinyl alcohol (PVA) and essential oil‐based biocomposite films incorporating halloysite nanotubes (HNTs) and cellulose nanocrystals (CNCs) as reinforcement materials for the packaging of papaya fruits to extend their postharvest shelf‐life. The fabrication process involves the dispersion of filler materials within the PVA polymer matrix, followed by the casting of the films using the solvent‐evaporation technique. The CNC isolated from the papaya peel exhibited rod‐like structures that were confirmed in the morphological studies. The films reinforced with HNT and CNC (5 wt%) had enhanced mechanical properties and exhibited a tensile strength of ~64.40 MPa. The findings of the study demonstrate that the fruits packed with biocomposite materials containing HNTs and CNCs as reinforcements and lemongrass essential oil as active material showed better performance when compared to the control. The edible quality and the storage life of the papaya fruits (TSS, firmness and weight loss %) under investigation were extended by 14 days at ambient temperature (25 °C ± 2 °C) and relative humidity (80%–85%), thus improving the postharvest shelf‐life of harvested papayas. Therefore, PVA‐based active packaging film prepared with lemongrass essential oil, HNTs and CNCs has great potential for the preservation of papaya during postharvest storage.

Carboxymethyl cellulose/poly (vinyl alcohol) based active film incorporated with tamarind seed coat waste extract for food packaging application

Incorporating a bioactive food waste extract into biodegradable polymers is a promising green approach to producing active films with antioxidant and antibacterial activity for food packaging. Active packaging films from carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) incorporated with tamarind seed coat waste extract (TS) were prepared by solvent casting method using citric acid as a crosslinking agent. The effect of TS content on the film properties was determined by measuring the optical, morphology, mechanical, water vapor transmission rate (WVTR), antioxidant, and antimicrobial attributes. The CMC/PVA-TS films were also tested on fresh pork. The addition of TS did not significantly affect the film structure and WVTR but it improved the mechanical and UV barrier properties. The films possessed antioxidant and antimicrobial ability against bacteria (S. aureus and E. coli). Thus, CMC/PVA packaging was successfully prepared, and the incorporation of TS enhanced the antioxidant and antimicrobial properties of the film, which extended the shelf-life of fresh pork.

Starch-based active packaging film and its application

Montmorillonite (MMT) was used to improve the performance of starch and nano-ZnO was added to act as antibacterial agent for developing a starch-based active packaging material via solution mixing and casting methods. The effect of MMT and ZnO on the performance of starch films was investigated, and then the composite films were used for cherry preservation. The results indicated that the addition of MMT could improve the mechanical and water-vapor barrier properties of starch films, but it had only a slight impact on optical properties. However, the addition of nano-ZnO could reduce the optical, mechanical, and water vapor barrier properties of composite films. In preservation applications, compared to the other films, the composite films containing nano-ZnO could be beneficial to maintain quality and nutritional value of cherries by slowing down the growth of bacteria and thereby delaying weight loss, decreasing hardness, and decreasing pH and soluble solid content, resulting in a better preservation effect. Therefore, a starch-based active packaging film with good properties and preservation effect was developed with nano-ZnO and MMT, which could be applied in the field of preservation.

Characterization of an eco-friendly active packaging film for food with ultraviolet light blocking ability

An eco-friendly active packaging film for food with ultraviolet (UV) light blocking ability was prepared using nano-magnesium oxide (MgO), nano-zinc oxide (ZnO), nano-cellulose (NCC), and poly(lactic acid) (PLA). The results revealed that the four nanomaterials were evenly dispersed in the PLA films, but no chemical bonds formed according to infrared spectroscopy and scanning electron microscopy. Compared with other PLA films, the PLA films with ZnO were endowed with excellent UV absorption and its surface hydrophilicity was decreased. On the contrary, the PLA films with MgO, ZnO, and NCC had improved mechanical strength, better antimicrobial activity, lower oxygen permeability (OP), and water vapor permeability (WVP). The PLA film with nanoparticles is an excellent active packaging material with improved physical, mechanical, and barrier properties, which can also avoid the damage of food or active ingredients in packaging from UV radiation, and has a broad application prospect for the preparation of multilayered composite active packaging materials for food.

Chitosan/gelatin-based multifunctional films integrated with sulfur-functionalized chitin for active packaging applications

Sulfur-functionalized chitin composite (S-chitin) was prepared through sulfur-amine complex formation using ethylenediamine. The S-chitin exhibited excellent antioxidant, antimicrobial, and UV-barrier properties. Chitosan/gelatin (CS/Gel)-based active packaging films containing S-chitin (CS/Gel@S-chitin) were prepared and characterized. The addition of S-chitin enhanced the tensile strength and elongation at the break of the CS/Gel film by 18.4% and 42.2%, respectively, and slightly lowered the transparency of the film but enhanced the UV-blocking with 98.7% UV-A and 100% UV-B light screening. The composite films showed strong antioxidant efficacy with 100% ABTS and 95.9% DPPH radical scavenging potential. The films exhibited effective antimicrobial activity and completely stopped the growth of L. monocytogenes and E. coli after 3 h and 12 h of incubation, respectively. Packaging chicken and storing at 4 °C for 20 days showed that the chicken packaged with the CS/Gel@S-chitin films preserved the quality of the chicken of appearance, pH, TBARS (thiobarbituric acid reactive substance), and TVC (total viable colony count). The multifunctional S-chitin incorporated CS/Gel films have a high potential for active packaging applications.

Functional properties of taro starch reinforced polysaccharide based films for active packaging

The current study involves the fabrication of polysaccharide-based films containing Chitosan (CS) -Pullulan (PL) and Taro starch (TS), all derived from conventional sources. The extraction of starch from Taro (Colocasia esculenta) tubers was carried out by employing the wet-milling process in the laboratory. The main study was aimed at studying the influence of added TS into the CS-PL matrix through various characterization techniques such as mechanical, structural, spectroscopic, thermal, morphological and biological studies. The added TS was found to enhance the tensile strength as well as the crystallinity of the chitosan/pullulan (CP) blend films. The blend films showed a decline in the opacity values with the addition of TS. The effective interaction between the blended components indicated stronger intermolecular hydrogen bonding between them which was confirmed through FTIR and DSC studies. The thermal analysis depicted that the TS incorporated blend films degraded at a slightly higher temperature than the control film. The developed films were found to be hydrophobic in nature, with increasing hydrophobicity with increase in concentration of TS. The fabricated films were found to be biologically active i.e., antimicrobial and antioxidant, which is due to the presence of certain active compounds present in the taro tubers. These outcomes suggest that these films can be harnessed as active packaging materials in the food industry.

Development of Plastic/Gelatin Bilayer Active Packaging Film with Antibacterial and Water-Absorbing Functions for Lamb Preservation

Development of Plastic/Gelatin Bilayer Active Packaging Film with Antibacterial and Water-Absorbing Functions for Lamb Preservation

UV-blocking active packaging film made from TEMPO-oxidized nanocellulose and amine-modified carbon quantum dot

UV-blocking active packaging film made from TEMPO-oxidized nanocellulose and amine-modified carbon quantum dot

Extending cheese shelf-life using eco-friendly sodium alginate-gelatin films reinforced with nanoclay

Eco-friendly antimicrobial food packaging materials are essential for extending the shelf life of food products, reducing food waste, and maintaining food quality while being biodegradable in nature. A food packaging material developed for cheese should control the moisture content, enhance antimicrobial properties and maintain the quality of cheese through storage. The current food packaging material was created by incorporating nanoclay (NC) (0.3 %, 0.5 %, and 1 % w/v) and clove essential oil (CEO) (1 % v/v) into a matrix of sodium alginate (SA) and gelatin via solvent casting for cheese (cheddar cheese) applications. The created packaging material's chemical, physical, and biological properties were evaluated. The Elongation at Break (EB) increased by 80.24%(1%NC-CEO) when compared to CEO (control). The water contact angle (WCA) film increased by 96.26% (1%NC-CEO) compared to the CEO (control) film. In addition to these characteristics, the films had enhanced barrier properties and a colour suitable for food packing. Increased antimicrobial activity against Escherichia coli, Listeria monocytogene, and Penicillium expansum was seen in the developed films. Importantly, the films biodegraded within 45 days. During the application trials, the CEO and NC-reported film extended the shelf-life of cheese to up to 15 days when stored at 4 °C while maintaining constant weight, pH, visual appearance, and microbiological growth inhibition. Hence, the proposed active packaging film can be employed as a biodegradable eco-friendly cheese packaging application.

Recent Advances in Functional Cellulose-based Films with Antimicrobial and Antioxidant Properties for Food Packaging.

The packaging of food plays a crucial role in food preservation worldwide. However, traditional packaging systems are passive layers with weak efficiency in protecting the food quality. Therefore, packaged foods are gradually spoiled due to the oxidation and growth of microorganisms. Additionally, most of the commercial packaging films are made of petroleum-based materials which raise environmental concerns. Accordingly, the development of eco-friendly natural-derived active packaging systems has increased the attention of scientists. Cellulose as the most abundant polysaccharide on earth with high biocompatibility, no toxicity, and high biodegradability has extensively been applied for the fabrication of packaging films. However, neat cellulose-based films lack antioxidant and antimicrobial activities. Therefore, neat cellulose-based films are passive films with weak food preservation performance. Active films have been developed by incorporating antioxidants and antimicrobial agents into the films. In this review, we have explored the latest research on the fabrication of antimicrobial/antioxidant cellulose-based active packaging films by incorporating natural extracts, natural polyphenols, nanoparticles, and microparticles into the cellulose-based film formulations. We categorized these types of packaging films into two main groups: (i) blend films which are obtained by mixing solutions of cellulose with other soluble antimicrobial/antioxidant agents such as natural extracts and polyphenols; and (ii) composite films which are fabricated by dispersing antimicrobial/antioxidant nano- or microfillers into the cellulose solution. The effect of these additives on the antioxidant and antimicrobial properties of the films has been explained. Additionally, the changes in the other properties of the films such as hydrophilicity, water evaporation rate, and mechanical properties have also been briefly addressed.

Experimental investigations on PVA/chitosan and PVA/chitin films for active food packaging using Oxytenanthera abyssinica lignin nanoparticles and its UV-shielding, antimicrobial, and antiradical effects

This study investigated the effect of adding lignin nanoparticles (LNPs) derived from Oxytenanthera abyssinica via alkali-acid nanoprecipitation method to polyvinyl alcohol/chitosan (PVA/CI) and polyvinyl alcohol/chitin (PVA/CH) films for the active food packaging applications. Adding LNPs at concentrations of 1 % and 3 % improved the films' thermal stability and mechanical properties. The lowest water solubility and moisture content were observed in PVA/CI/LNPs films. LNPs exhibited effective 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, with the highest values observed in PVA/CH/LNPS and PVA/CI/LNPS films with values of 87.47 and 88.74 % respectively. The addition of LNPs also improved the UV-blocking abilities of the films. PVA/CH/LNP3 and PVA/CI/LNP3 have the smallest percentage transmission values of 3.34 % and 0.86 % in the UV range. The overall migration of dietary stimulants was lower in PVA/CI/LNPS and PVA/CH/LNPS films compared to PVA film. Antibacterial tests demonstrated the inhibitory capacity of the synthesized biofilms against both gram-positive and negative bacterial species, with the highest inhibitory value of 26 mm. The study suggests that PVA/CH/LNPS and PVA/CI/LNPS films have potential applications as active food packaging materials and can be explored in other potential applications such as drug delivery, tissue engineering, wound healing, and slow-release urea fertilizer development.

Carboxymethyl cellulose based films enriched with polysaccharides from mulberry leaves (Morus alba L.) as new biodegradable packaging material

The objective of this study was to determine the properties of a new active packaging film developed by the addition of mulberry leaves polysaccharides (MLP) into carboxymethyl cellulose (CMC). Biodegradable CMC-MLP films were fabricated by casting method with various concentrations of MLP (1, 5 and 10 % w/w). The addition of MLP into the CMC matrix resulted increased thickness (0.126 to 0.163 mm) and roughness of the films. Also, the decline in moisture content from 27.91 to 14.12 %, water vapor permeability from 8.95 to 5.21 × 10−10 g−1 s−1 Pa−1, and a swelling degree from 59.11 to 37.45 % were observed. With the increasing concentration of MLP, the mechanical properties of the films were improved and higher dispersion of UV light were noted. Fourier transform - infrared spectroscopy (FT-IR) and X-ray diffraction revealed good inter-molecular interaction between CMC matrix and MLP. The prepared films showed excellent thermal stability, antioxidant and antibacterial properties as well as susceptibility to biodegradation in the soil environment. Moreover, it was proved that the films have ability to retard oil oxidation. Overall, it was concluded that CMC-MLP films constitute a promising biomaterial that may be applied as active food packaging.

Gelatin-sodium alginate packaging film with date pits extract: An eco-friendly packaging for extending raw minced beef shelf life

Gelatin-sodium alginate-based active packaging films were formulated by including date pits extracts (DPE), as bioactive compound, in raw minced beef meat packaging. The DPE effects at 0.37, 0.75 and 1.5% (w/w, DPE/ gelatin-sodium alginate) on physical, optical, antioxidant and antibacterial properties of established films were assessed. Findings showed that film lightness decreased with the incorporation of DPE. Physical, antioxidant and anti-food-borne pathogens capacities were enhanced by increasing DPE concentration in the films. For 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), the films with 1.5% DPE had the greatest levels (94 and 88%, respectively). DPE films (1.5%) also exhibited the highest anti-Listeria moncytogenes activity, with an inhibition zone of 25 mm. Moreover, during 14 days at 4 °C, the bio-preservative impact of gelatin-sodium alginate film impregnated with DPE at three levels on microbial, chemical, and sensory characteristics of meat beef samples was evaluated. By the end of the storage, DPE at 1.5% enhanced the instrumental color, delayed chemical oxidation and improved sensory traits. By chemometric techniques (principal component analysis (PCA) and heat maps), all data allowed to obtain helpful information by segregating all the samples at each storage time. PCA and heat maps could connect oxidative chemical changes, instrumental color parameters, and microbiological properties to sensory attributes. These data offer an approach to well interpreting the sensory quality and how they are affected by chemical and microbiological changes in the studied meat samples. Our findings indicated the potential of the gelatin-sodium alginate film incorporated with DPE for enhancing meat safety and quality.

Novel active composite films based on carboxymethyl cellulose and sodium alginate incorporated with phycocyanin: Physico-chemical, microstructural and antioxidant properties

Phycocyanin (PC) has been demonstrated to be an excellent source of antioxidant activities. The antioxidant capacity of biopolymer based packaging films should be enhanced with PC incorporation. For further elucidation of this hypothesis, edible packaging films were prepared by adding PC into carboxymethyl cellulose (CMC), sodium alginate (SA), and their combination (CMC/SA), respectively. The effects of PC addition on morphological and physico-chemical properties were investigated. Meanwhile, the antioxidant capacity including DPPH and ABTS radical scavenging activity were also determined. The results depicted that the moisture content, water solubility, water vapor and oxygen permeability of the films were decreased, but thickness was increased by the addition of PC. The tensile strength, elongation at break, and elastic modulus were also improved. The transparency of PC added films was reduced due to blue color of PC. Scanning electron microscopic analysis showed that the surface of the film was homogenous for the control but cracks were noted in PC added films, which improved the film structure. A good physical interaction was reflected by Fourier transform infrared spectroscopy analysis among CMC, SA, and PC. Moreover, the antioxidant capacity also showed enhanced trend depending on increasing concentration of PC. Therefore, PC incorporation into CMC and/or SA based film was an efficient manner to produce eco-friendly and active edible packaging films for fresh food preservation application.

Cinnamon essential oil Pickering emulsions: Stabilization by bacterial cellulose nanofibrils and applications for active packaging films

Pickering emulsions are emulsions stabilized by solid particles with a wide range of potential applications as they typically provide more stable systems than surface-stabilized emulsions. Among the various solid stabilizers, bacterial cellulose (BC) may open up new opportunities for future Pickering emulsions due to its unique nano-size, amphiphilicity and other excellent properties. In this study, BC, TEMPO-oxidized BC (TOBC) and dialdehyde cellulose (DAC) were used as emulsifiers to stabilize cinnamon essential oil (CEO) Pickering emulsions. The microstructure, oil droplet size distribution, storage and loss moduli of the Pickering emulsions were affected by the type of emulsifier used. Compared to BC and DAC nanofibers, TOBC nanofibers exhibited better emulsifying capacity. TOBC (1%)-stabilized Pickering emulsion showed smaller droplet size, narrower size distributions, better stability and sustained release ability. Moreover, the Pickering emulsions showed high antibacterial activities against Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli. Active gelatin composite films containing TOBC (1%)-stabilized CEO Pickering emulsions were successfully fabricated and showed good antibacterial and antioxidant properties, which make them suitable for food packaging application.

Morphological, thermo-mechanical, and barrier properties of coextruded multilayer polylactide composite films reinforced with graphene nanoplatelets and encapsulated thyme essential oil

The food industry has been looking for biodegradable active packaging film, which has a lower environmental footprint and can extend shelf-life. This work aimed to develop a polylactide-based antibacterial nanopackaging with a tri-layer structure. This coextruded tri-layer film was composed of an internal extruded layer of polylactide (PLA), a central layer of PLA loaded with encapsulated thyme essential oil, and an outer layer of PLA with graphene nanoplatelets. The tri-layer packaging films' morphological, rheological, thermal, barrier, and antibacterial properties were evaluated and compared to those of their single-layer counterparts. Dispersion of nanoparticles in PLA matrix or in composites is described by rheological, thermal, and XRD analysis. The multilayer films displayed some roughness on the surface, and heterogeneity can be seen through phase imaging compared to single-layer films. Antibacterial assays of the film confirmed a strong bactericidal effect against gram-positive and gram-negative bacteria, maintaining this activity for 21 days.

Preparation and characterization of bioactive binary composite film based on gelatin–dextran incorporated with citronellal and α‐tocopherol

AbstractBiodegradable active packaging films with antimicrobial and antioxidant functions have received much attention due to the food safety and plastic pollution issues. This study prepared and characterized a novel bioactive binary composite film based on gelatin (Ge) and dextran (Dx) incorporated with various concentrations (0%, 0.3%, 0.6%, 0.9%, 1.2%, w/w) of citronellal (Cit) and α‐tocopherol (Toc). The thickness, L*, b*, total color difference, water contact angle, opacity, and crystallinity of film significantly increased, whereas the film solubility, swelling degree, water vapor permeability, tensile strength, elongation at break, and a* of film significantly decreased with the increase of Cit and Toc concentrations. However, the addition of Cit and Toc had no significant effect on the film's moisture content and thermal stability. Fourier transforms infrared spectral pattern indicated that physical interactions (H‐bonding) between biopolymer matrix and active fillers were formed. Scanning electron microscope images showed that the film added with active fillers had a rough surface and a spongelike cross‐section structure compared to control film. Moreover, the release curves of Cit and Toc showed that the film in 95% ethanol solution had the longest release time. Furthermore, the film added with Cit and Toc effectively inhibited the growth of pathogenic and spoilage bacteria (Shewanella putrefaciens and Escherichia coli) and quenched the free radicals (2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic acid)). Overall, it can be inferred that the Ge–Dx‐based composite film incorporated with Cit and Toc is a potential antibacterial and antioxidant biodegradable material for food packaging applications to maintain food quality.

Synergistic effect of graphene oxide/zinc oxide nanocomposites on polylactic acid-based active packaging film: Properties, release kinetics and antimicrobial efficiency

Incorporating two different nanoparticles in nanocomposite films is promising as their synergistic effects could significantly enhance polymer performance. Our previous work conferred the remarkable antimicrobial (AM) properties of the polylactic acid (PLA)-based film using optimal formulations of synergistic graphene oxide (GO)/zinc oxide (ZnO) nanocomposites. This study further explores the release profile of GO/ZnO nanocomposite and their impact on the antimicrobial properties. A fixed 1.11 wt% GO and different ZnO concentrations were well dispersed in the PLA matrix. Increasing ZnO concentrations tended to increase agglomeration, as evident in rougher surfaces. Agglomeration inhibited water penetration, leading to a significant reduction in water permeability (46.3 %), moisture content (31.6 %) but an improvement in Young's Modulus (52.6 %). The overall and specific migration of GO/ZnO nanocomposites was found to be within acceptable limits. It is inferred that the release of Zn2+ ions followed pseudo-Fickian behavior with an initial burst effect. AM film with the highest concentration of ZnO (1.25 wt%) exhibited the highest inhibition rate against Escherichia coli (68.0 %), Bacillus cereus (66.5 %), Saccharomyces cerevisiae (70.9 %). Results suggest that GO/ZnO nanocomposites with optimal ZnO concentrations have the potential to serve as promising antimicrobial food packaging materials, offering enhanced barrier, antimicrobial properties and a controlled release system.

Controlled release mechanism of thymol loaded into mesoporous silica nanoparticles for active packaging films

In order to overcome the poor water solubility and instability of thymol to enhance its bioavailability, mesoporous silica nanoparticles (MSNPs: SBA-15, SBA-16 and MCM-41) with different pore structures were developed using solution-gel method to carry and release thymol. The N2 adsorption-desorption test showed thymol-loaded MSNPs contained significantly low surface areas, pore sizes and pore volumes. When the ratio of thymol to MSNPs was 3:1, the loading capacity (LC) of MSNPs reached the highest (SBA-15: 35.20%, SBA-16: 30.84%, and MCM-41: 44.23%). The X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and microstructure characterization confirmed that thymol encapsulation process was successful. TGA results showed that the encapsulation of MSNPs improved thymol stability. The zeta-potential results confirmed that thymol loading increased the intermolecular repulsion of thymol-loaded MSNPs, which was beneficial to its dispersibility in the film. Additionally, thymol release experiment revealed a sustainable release behavior of thymol for MSNPs within 10 d. The release mechanism was adjusted according to the Korsmeyer-Peppas model, which showed thymol obeyed Fickian diffusion process. Notably, both thymol-loaded MSNPs and thymol-loaded MSNPs/potato starch films showed a remarkable antimicrobial efficiency against S. aureus. Therefore, thymol-loaded MSNPs provide feasible guidelines for the development of active packaging films and the on-demand release of active substances.