Konjac glucomannan (KGM), a polysaccharide extracted from konjac, is a safe and edible polysaccharide substance. Many recent studies have reported a series of applications for converting KGM into ...active food packaging films. However, the pure KGM-based film lacks mechanical properties or gas barrier properties due to strong hydrophilicity, so it has several disadvantages that cannot satisfy the needs of actual food packaging applications. Several effective strategies have been developed to obtain KGM-based films with improved properties. This review comprehensively reviewed the results of recently published studies on functional and physical properties enhancement of KGM-based films. We discussed the advantages and challenges of some strategies used to improve the performance of KGM-based films, including blending with other biopolymers or active materials, emulsion-based film systems, multilayer film systems, electrospinning, and microfluidic spinning techniques. We also discussed the practical application of KGM-based films for active food packaging.
Display omitted
•Konjac glucomannan (KGM) is a promising natural biopolymer for active packaging films.•Various strategies are used to enhance the KGM film properties.•KGM film properties can be improved by mixing biopolymer with functional materials.•Emulsion and multilayer films can expand the potential applications of KGM films.•Electrospinning and microfluidic spinning are excellent strategies to improve KGM film properties.
Display omitted
•Aerogels are nanostructured materials with low bulk density and open porosity.•Food-grade aerogels are prepared from several bio-based materials.•Aerogels can be loaded to obtain ...delivery systems for food and packaging applications.•Aerogels can turn into oleogels by oil absorption within the pores.
Aerogels are nanostructured materials with low density, high surface area (>150 m2/g) and open porosity (typically 95–99.99 %). They are obtained by solvent removal from gels while preserving network structure. Hydrogels, organogels and even tissues can be optimal sources of aerogels with limitless customization of format and texture. Aerogels might be used for a range of advanced food applications: from smart ingredients controlling nutrient release to delivery systems for active compounds; from fat substitutes to novel biodegradable and intelligent food packaging materials. This review article summarizes recent developments of aerogels in food applications, analyzing research challenges and prospecting future markets.
In this study, three EOs, namely cinnamaldehyde (CEO), limonene (LEO) and eugenol (EEO), together with β-cyclodextrins (βCD) were encapsulated in the core of nanofibers via coaxial electrospinning to ...improve the functional properties of fish gelatin mat. The successful fabrication of nanofibers was verified by transmission electron microscopy (TEM) and an average fiber diameter of 251–378 nm was observed by scanning electron microscopy (SEM). Attenuated Fourier-transform infrared (ATR-FTIR) indicated a physical type of interaction between gelatin and EOs. Melting temperature (Tm) of nanofiber mats was improved with the incorporation of EOs-βCD while reduced mechanical strength was noticed. The encapsulation efficiency (EE) of EOs in nanofiber mats ranged from 69.7 to 93.2%. A significantly enhanced antioxidant activity was noticed for nanofiber mats as evaluated through 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assay. Similarly, nanofiber mats presented strong antifungal activity when tested against Aspergillus niger. The developed nanofibers provided decent functional stability for 60 days by preserving the activity of dually encapsulated EOs. Finally, the nanofiber mats offered good control against the microbial spoilage of wheat bread stored for 10 days at ambient conditions. Thus, the developed nanofiber mats could be suitable for potential application as active packaging for low-to-intermediate moisture foods.
Display omitted
•Essential oils with β-cyclodextrins (EOs-βCD) were encapsulated in gelatin nanofibers.•Active nanofiber mats displayed greater antioxidant and antifungal activities.•Tensile strength and elongation at break of nanofiber mats were reduced.•Nanofiber mats remained functionally stable till 60 days at ambient conditions.•Mats controlled the bacteria and yeast and mould growth in preservative-free bread.
The novel multifunctional active packaging composite film with antimicrobial, antioxidant, water-vapor and UV-barrier, and corrosion resistance properties was successfully prepared from waste ...biomass. In this study, waste poplar sawdust was pretreated using green liquor to extract black liquor (BL). BL was then mixed with polyvinyl alcohol (PVA) solution for synthesizing silver nanoparticles (AgNPs). PVA-BL-AgNPs film was fabricated by solution casting method, and the microstructure characterization and macroscopic performance testing of the composite film were conducted. The results revealed that PVA-BL-AgNPs film exhibited inhibitory effects against Staphylococcus aureus (inhibition zone: 33.6 mm), Pseudomonas aeruginosa (inhibition zone: 31.6 mm), and Escherichia coli (inhibition zone: 32.0 mm). It could eliminate over 99 % of 2,2-diazodi (3-ethyl-benzothiazol-6-sulfonic acid) (ABTS) free radicals and provided 100 % UV-blocking, reducing light-induced food damage. It exhibited the improvement of water-vapor barrier properties and corrosion resistance. In vitro cytotoxicity assays demonstrated that no significant impact occurred on cell proliferation, confirming the safety of the film. Packaging experiments showed that PVA-BL-AgNPs film effectively inhibited milk spoilage and prolonged the shelf-life of bread and bananas. Therefore, PVA-BL-AgNPs film might extend the shelf-life of food and offer significant opportunities in addressing the issues of low safety and environmental pollution associated with traditional packaging films.
Display omitted
This study aimed to assess the effect of coating based on nanochitosan-whey protein isolate (NCH-WPI) containing summer savory essential oil (SEO) combined with oxygen absorber (OA) packaging on ...Pseudomonas aeruginosa, Listeria monocytogenes, and Escherichia coli O157H7, inoculated to rainbow trout fillets stored under refrigeration. Except control and OA groups, L. monocytogenes decreased (0.49–1.82 log CFU/g) in all treatment groups until the eighth day, and then increased (0.39–0.68 log CFU/g). This indicates that the treatments were ineffective to inhibit the proliferation of this bacterium. Considering the forced aerobic nature of inoculated P. aeruginosa, the counts of these bacteria become undetectable in groups packed with OA after the fourth day of storage, while the other groups showed an increase (0.99–2.23 log CFU/g) in this bacteria population during entire storage period. This growth rate was slower in the NCH-WPI + 1%SEO and NCH-WPI + 2%SEO groups. Regarding the inoculated E. coli, its count was decreased (1.48–2.41 log CFU/g) during storage, and this reduction (2.24–2.41 log CFU/g) was the highest in NCH-WPI + 1%SEO + OA and NCH-WPI + 2%SEO + OA groups. In conclusion, NCH-WPI treatments delayed the growth of all pathogenic bacteria, but the ternary treatment (NCH-WPI + SEO + OA) was the most effective treatment in this regard.
Current environmental concerns fostered a strong interest in extracting polymers from renewable feedstocks. Chitosan, a second most abundant polysaccharide after cellulose, may prove to be a ...promising green material owing to its renewability, inherent biodegradablity, natural availability, non-toxicity, and ease of modification. This review is intended to comprehensively overview the recent developments on the isolation of chitosan from chitin, its modification and applications as a reinforcing candidate for food packaging materials, emphasizing the scientific underpinnings arising from its physicochemical properties, antimicrobial, antioxidant, and antifungal activities. We review various chitosan-reinforced composites reported in the literature and comprehensively present intriguing mechanical and other functional properties. We highlight the contribution of these mechanically robust and responsive materials to extend the shelf-life and maintain the qualities of a wide range of food commodities. Finally, we assess critical challenges and highlight future opportunities towards understanding the versatile applications of chitosan nanocomposites.
Display omitted
Active packaging films (CCG/PL) based on collagen, functionalized chitosan with gallic acid (GA), and ε-polylysine (ε-PL) (different amount of 2.5, 5, and 10 wt%, respectively) were developed to ...prolong the shelf life of pork stored at 4 °C. Fourier transform infrared analysis indicated that hydrogen bonds had formed between collagen molecules and GA moieties, and there were no strong interactions between polymers and ε-PL. SEM images showed that the cross-sections of CCG/PL films were compact but aggregation of ε-PL occurred when ε-PL content reached 10 wt%. CCG/PL films possessed strong light barrier properties with the UV light transmittance lower than 4% in the range of 200–350 nm. Compared with CC film, the DPPH free radical scavenging rate was significantly increased by 84.35% due to the synergistic effect of GA and ε-PL on antioxidant activity. CCG/PL film containing 5 wt% ε-PL had excellent antimicrobial activity against S. aureus as well as good tensile strength (65.34 MPa). The wrapping of CCG/PL film with 5 wt% ε-PL effectively retarded the lipid oxidation of pork and inhibited the growth of bacterium during the storage time, and the shelf life of pork was prolonged by approximately 5 days than that of pork in polyethylene film.
Display omitted
•Active packaging films based on collagen (COL) were developed.•Gallic acid-grafted chitosan was used to improve the antioxidant activity of COL film.•ε-polylysine (ε-PL) was added to further enhance the antimicrobial activity of the film.•Film with 5 wt% ε-PL had good functional activities and tensile strength.•The shelf life of pork wrapped in film with 5 wt% ε-PL was extended by ∼5 days.
The massive and uncontrolled use of food packaging derived from petroleum-based plastics has created a serious environmental problem. Hence, the food packaging industry needs to develop packaging ...from biodegradable polymers. Among the many raw materials studied in the literature, chitosan is one of the most abundant polysaccharides in the nature. Chitosan has attracted attention due to its non-toxicity, antimicrobial, and antifungal properties. Because of this, chitosan is considered a perfect material for the development of films for food use. In this review, recent studies on active and/or intelligent chitosan-based films has been evaluated. Active packaging maintains or improves the condition of packaged food or extends its shelf-life meanwhile intelligent packaging monitors the condition of packaged food or the environment surrounding the food. The effect of the addition of active compounds on the mechanical, barrier and functional properties of chitosan-based films has been assessed. The antimicrobial and antioxidant activity, as well as the potential application of these active and intelligent composite films have also been revised. Literature shows that the presence of phenolic compounds improves both mechanical and barrier properties of chitosan films. The antimicrobial and antioxidant capacity of the films improved significantly by the addition of essential oils, phenolic compounds, and other fruit extracts. Intelligent pH-indicator chitosan-based films have been extensively studied. Further research on chitosan and its combinations with other materials is needed to study which type of foodstuffs could be in contact with chitosan packaging.
Display omitted
•Food packaging derived from petroleum has created a serious environmental problem.•Chitosan is considered a perfect material for the development of films for food use.•Recent studies on active and/or intelligent chitosan-based films has been evaluated.•Further research on chitosan is needed to study foodstuffs in contact with chitosan packaging.
Display omitted
•Herein, we reviewed the potential of bio-based food packaging materials as an alternative to petro- materials.•Effective deployment of suitable packaging material is a growing ...concern.•The broader applied spectrum of polymeric materials is discussed with suitable examples.
In food industry, a growing concern is the use of suitable packaging material (i.e., biodegradable coatings and films) with enhanced thermal, mechanical and barrier characteristics to prevent from contamination and loss of foodstuff. Biobased polymer resources can be used for the development of biodegradable bioplastics. To achieve this goal, biopolymers should be economic, renewable and abundantly available. Bioplastic packaging materials based on renewable biomass could be used as sustainable alternative to petrochemically-originated plastic materials. This review summarizes the recent advancements in biopolymer-based coatings and films for active food packaging applications. Microbial polymers (PHA and PLA), wood-based polymers (cellulose, hemicellulose, starch & lignin), and protein-based polymers (gelatin, keratin, wheat gluten, soy protein and whey protein isolates) were among the materials most widely exploited for the development of smart packaging films. These biopolymers are able to synthesize coatings and films with good barrier properties against food borne pathogens and the transport of gases. Biobased reinforcements e.g., plant essential oils and natural additives to bioplastic films improve oxygen barrier, antibacterial and antifungal properties. To induce the desired functionality the simultaneous utilization of different synthetic and biobased polymers in the form of composites/blends is also an emerging area of research. Nanoscale reinforcements into bioplastic packaging have also been reported to improve packaging characteristics ultimately increasing food shelf life. The development of bioplastic/biocomposite and nanobiocomposites exhibits high potential to replace nonbiodegradable materials with characteristics comparable to fossil-based plastics, additionally, giving biodegradable and compostable characteristics. The idea of utilization of renewable biomass and the implications of biotechnology can firstly reduce the burden from fossil-resources, while secondly promoting biobased economy.
Contamination of food by spoilage and pathogenic microorganisms is a major challenge to public health, food security and sustainability. As a response, there has been a growing interest in the ...exploration of alternative antimicrobial agents such as essential oils. Although essential oils can be potent antimicrobials, they are chemically and biologically labile and have strong aromas which limit their application as food antimicrobial additives. This has shifted essential oil research from direct food applications towards the use of encapsulated essential oils in active packaging. Various encapsulation methods are increasingly being explored as a way of stabilizing essential oils, masking their aromas and possibly improving their antimicrobial activity with a more sustained release of the antimicrobials. Encapsulated essential oils have mainly been investigated as direct preservatives but their merit in active packaging is comparatively less explored. The current review will critique some currently available encapsulation techniques and their effect on the antimicrobial efficacy, release profiles, stability and sensory properties of the essential oils. Furthermore, the application of encapsulated essential oils in biodegradable active packaging will be explored by focusing on the antimicrobial efficacy, release properties and physicochemical properties of the packaging.
PDF
