Development of a Sodium Alginate-Based Active Package with Controlled Release of Cinnamaldehyde Loaded on Halloysite Nanotubes

Preparation of sodium alginate and xanthan gum bionanocomposite films reinforced with hybrid halloysite nanotubes containing ZnO and licorice root extract for wound dressing applications

This study aims to fabricate bio-nanocomposite films using a solution-casting method based on sodium alginate (SA)1 and xanthan gum (XG).2 These films are reinforced with hybrid Halloysite nanotubes (Hal)3 containing zinc oxide nanoparticles (ZnO-Hal) and licorice root extract (ZnO-Hal-LRE) in various concentrations. These films were characterized using FT-IR, XRD, and scanning electron microscopy (SEM). The ZnO-Hal-LRE nanohybrids significantly enhanced the films' mechanical properties, thermal stability, and water vapor permeability (WVP) barrier. The tensile strength (TS) increased from 6 MPa to 13.204 MPa, and the WVP improved from 1.82 × 10-9 g·m·m-2·h-1·Pa-1 to 1.25 × 10-9 g·m·m-2·h-1·Pa-1. Furthermore, incorporating LRE4 into the nanohybrids enhanced antibacterial and antioxidant activities and increased the cell viability of NIH-3T3 fibroblast cells. The in vitro release study of licorice extract from the nanocomposite film demonstrated a controlled and sustained release, prolonging the half-life of the licorice extract. These findings indicate that the prepared bio-nanocomposite films have significant potential for biomedical applications, particularly wound dressing.

Layer-by-layer assembly of modified halloysite nanotube using chitosan and sodium alginate to control the release of carvacrol and improve its stability

This study focused on the encapsulation of modified halloysite nanotubes (AHNT) using sodium alginate (SA) and chitosan (CS) through a layer-by-layer assembly technique. The objective was to develop new composites (CPs) that could control the release of carvacrol (Car) and enhance its stability. The influence of various conditions on the microstructure, chemical properties, and slow-release effects of the CPs was examined by adjusting the pH and concentration of the CS solution. The results indicated that the CPs (CS4.5-1), created with a CS solution concentration of 1 mg/mL at a pH of 4.5, in conjunction with a 1 mg/mL SA solution, demonstrated a superior encapsulation structure and a loading efficiency of 26.33 %. In vitro release experiments confirmed that the CPs exhibited effective slow-release properties for Car. Furthermore, the CS4.5-1 composite provided a physical barrier that resulted in the retention of 94.90 % and 83.61 % of Car after 6 h of exposure to UV light and heat, respectively. Antimicrobial and antioxidant assays indicated that CS4.5-1/Car possessed significant antioxidant properties and effectively inhibited the growth of E. coli and S. aureus. Consequently, the prepared CPs have the potential to enhance the bioactivity of active compounds and may be beneficial for food preservation and other applications.

Fabrication and characterization of an alginate-based film incorporated with cinnamaldehyde for fruit preservation

Sodium alginate (SA) is widely used in the food, biomedical, and chemical industries due to its biocompatibility, biodegradability, and excellent film-forming properties. This article introduces a simple method for preparing uniform alginate-based packaging materials with exceptional properties for fruit preservation. The alginate was uniformly crosslinked by gradually releasing calcium ions triggered by the sustained hydrolysis of gluconolactone (GDL). A cinnamaldehyde (CA) emulsion, stabilized by xanthan without the use of traditional surfactants, was tightly incorporated into the alginate film to enhance its antimicrobial, antioxidant, and UV shielding properties. The alginate-based film effectively blocked ultraviolet rays in the range of 400-200 nm, while allowing for a visible light transmittance of up to 70 %. Additionally, it showed an increased water contact angle and decreased water vapor permeability. The alginate-based film was also employed in the preparation of coated paper through the commonly used coating process in the papermaking industry. The alginate-based material displayed excellent antioxidant properties and antimicrobial activity against Escherichia coli, Staphylococcus aureus and Botrytis cinerea, successfully extending the shelf life of strawberries to 7 days at room temperature. This low-cost and facile method has the potential to drive advancements in the food and biomedical fields by tightly incorporating active oil onto a wide range of biomacromolecule substrates.

A polylactide based multifunctional hydrophobic film for tracking evaluation and maintaining beef freshness by an electrospinning technique

A nanofiber film was prepared by a facile electrospinning technique using polylactide (PLA), butterfly pea flower extract (BPA) and cinnamaldehyde (CIN). The as-prepared film shows the prominent antioxidative, antibacterial, colorimetric and hydrophobic properties so that the beef freshness can be monitored and maintained up to 6 days at 4 °C simultaneously. Besides, the nanofiber structure endows the film with a fast color responsiveness under acidic-alkaline atmospheres with different concentrations. Moreover, this film exhibits higher tensile strength (9.56 Mpa) than that of the pure PLA electrospinning film (4.40 Mpa). Especially the introduction of the BPA effectively boosts the antimicrobial ability of the CIN. The freshness, sub-freshness and spoilage levels of the beef can be easily testified by observing the color difference change of the film. So the polylactide based multifunctional film as an intelligent packaging has an excellent potential for the sub-freshness detection of meat.

Inhibition of Salmonella Enteritidis by Essential Oil Components and the Effect of Storage on the Quality of Chicken

This research investigates the antibacterial potential of plant essential oil components including thymol, carvacrol, citral, cinnamaldehyde, limonene, and β-pinene against Salmonella Enteritidis (S. Enteritidis). Through the determination of minimum inhibitory concentration, three kinds of natural antibacterial agents with the best inhibitory effect on S. Enteritidis were determined, namely thymol (128 μg/mL), carvacrol (256 μg/mL), and cinnamaldehyde (128 μg/mL). Physical, chemical, microbial, and sensory characteristics were regularly monitored on days 0, 2, 4, and 6. The findings of this study reveal that both thymol at MIC of 128 μg/mL and carvacrol at MIC of 256 μg/mL not only maintained the sensory quality of chicken, but also decreased the pH, moisture content, and TVB-N value. Additionally, thymol, carvacrol and cinnamaldehyde successfully inhibited the formation of S. Enteritidis biofilm, thereby minimizing the number of S. Enteritidis and the total aerobic plate count in chicken. Hence, thymol, carvacrol, and cinnamaldehyde have more effective inhibitory activities against S. Enteritidis, which can effectively prevent the spoilage of chicken and reduce the loss of its functional components.

Plant Antimicrobials for Food Quality and Safety: Recent Views and Future Challenges

The increasing demand for natural, safe, and sustainable food preservation methods drove research towards the use of plant antimicrobials as an alternative to synthetic preservatives. This review article comprehensively discussed the potential applications of plant extracts, essential oils, and their compounds as antimicrobial agents in the food industry. The antimicrobial properties of several plant-derived substances against foodborne pathogens and spoilage microorganisms, along with their modes of action, factors affecting their efficacy, and potential negative sensory impacts, were presented. The review highlighted the synergistic or additive effects displayed by combinations of plant antimicrobials, as well as the successful integration of plant extracts with food technologies ensuring an improved hurdle effect, which can enhance food safety and shelf life. The review likewise emphasized the need for further research in fields such as mode of action, optimized formulations, sensory properties, safety assessment, regulatory aspects, eco-friendly production methods, and consumer education. By addressing these gaps, plant antimicrobials can pave the way for more effective, safe, and sustainable food preservation strategies in the future.

Protective effect of Anneslea fragrans ethanolic extract against CCl4-induced liver injury by inhibiting inflammatory response, oxidative stress and apoptosis

Anneslea Fragrans Wall. (AF) is a medicinal and edible plant distributed in China. Its leaves and bark generally used for the treatments of diarrhea, fever, and liver diseases. While its ethnopharmacological application against liver diseases has not been fully studied. This study was aimed to evaluate the hepatoprotective effect of ethanolic extract from A. fragrans (AFE) on CCl₄ induced liver injury in mice. The results showed that AFE could effectively reduce plasma activities of ALT and AST, increase antioxidant enzymes activities (SOD and CAT) and GSH level, and decrease MDA content in CCl₄ induced mice. AFE effectively decreased the expressions of inflammatory cytokines (IL-1β, IL-6, TNF-α, COX-2 and iNOS), cell apoptosis-related proteins (Bax, caspase-3 and caspase-9) and increased Bcl-2 protein expression via inhibiting MAPK/ERK pathway. Additionally, TUNEL staining, Masson and Sirius red staining, immunohistochemical analyses revealed that AFE could inhibit the CCl₄-induced hepatic fibrosis formation via reducing depositions of α-SMA, collagen I and collagen III. Conclusively, the present study demonstrated that AFE had an hepatoprotective effect by MAPK/ERK pathway to inhibit oxidative stress, inflammatory response and apoptosis in CCl₄-induced liver injury mice, suggesting that AFE might be served as a hepatoprotective ingredient in the prevention and treatment of liver injury.

Nanoclays-containing bio-based packaging materials: properties, applications, safety, and regulatory issues

Food packaging is an important concept for consumer satisfaction and the increased shelf life of food products. The introduction of novel food packaging materials has become an emerging trend in recent years, which could be mainly due to environmental pollution caused by plastic packaging and to reduce food waste. Recently, numerous studies have been carried out on nanoclays or nanolayered silicate to be used in packaging material development as reinforcing filler composites. Different types of nanoclays have been used as food packaging materials, while montmorillonite (MMT), halloysite, bentonite (BT), Cloisite, and organically modified nanoclays have become of great interest. The incorporation of nanoclays into the packaging matrix improves the mechanical and barrier properties and at the same time prolongs the biodegradation of the packaging material. The purpose of this article is to examine the development of nanoclay-based food packaging materials. The review article highlights the current state of research on bio-based polymers with nanoclay for food packaging. In addition, the report analyses the mechanical, barrier, and antibacterial characteristics of nanoclay-based food packaging materials. Finally, it discusses the migration of nanoclays, toxicity levels, and the legislation associated with the application of nanoclays.

Graphical abstract

Antimicrobial Nanomaterials Based on Halloysite Clay Mineral: Research Advances and Outlook

Bacterial infections represent one of the major causes of mortality worldwide. Therefore, over the years, several nanomaterials with antibacterial properties have been developed. In this context, clay minerals, because of their intrinsic properties, have been efficiently used as antimicrobial agents since ancient times. Halloysite nanotubes are one of the emerging nanomaterials that have found application as antimicrobial agents in several fields. In this review, we summarize some examples of the use of pristine and modified halloysite nanotubes as antimicrobial agents, scaffolds for wound healing and orthopedic implants, fillers for active food packaging, and carriers for pesticides in food pest control.

Study of antimicrobial activity and mechanism of vapor-phase cinnamaldehyde for killing Escherichia coli based on fumigation method

The vapor-phase antibacterial activity of essential oils makes them suitable for applications in air disinfection and other fields. At present, vapor-phase antibacterial activity of plant-based essential oils has rarely been reported. Herein, we report a new approach to investigate the antimicrobial activity and mechanism of vapor-phase cinnamaldehyde using Escherichia coli (E. coli) and three other pathogenic bacteria (Pseudomonas aeruginosa, Salmonella, Staphylococcus aureus) as model bacteria. Plate fumigation and agar block transfer techniques were used to determine the antimicrobial activities of vapor-phase cinnamaldehyde fumigation on the four types of bacteria, and the mechanism of action was determined by electrical conductivity (EC), OD260nm measurement, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and fluorescence spectroscopy. Cinnamaldehyde had good vapor-phase antibacterial activity against the four types of bacteria. The TEM, EC, and OD260nm measurements showed that after fumigation with cinnamaldehyde, the ultrastructures of the cells were damaged, and plasmolysis, cell collapse, and leakage of intracellular substances were observed. The FTIR and fluorescence spectroscopy analyses showed that the secondary and tertiary structures of bacterial membrane proteins were altered. These findings indicate that the cell membrane is an important target for plant-based essential oils to exert their vapor-phase antimicrobial effects. The results showed that plant-based essential oils can be developed as volatile broad-spectrum disinfection products and vapor-phase antiseptics.

Preparation of sodium alginate films incorporated with hydroalcoholic extract of Macrocystis pyrifera

Agroindustry needs novel materials to replace synthetic plastics. This article introduces sodium alginate films with antioxidant properties. The films, which were incorporated with hydroalcoholic extract of Macrocystis pyrifera, were tested on sliced Hass avocados. The research featured sodium alginate films incorporated with hydroalcoholic extracts of M. pyrifera. Uncoated avocado halves served as control, while the experimental samples were covered with polymer film with or without hydroalcoholic extract. A set of experiments made it possible to evaluate the effect of the extracts on polymeric matrices, release kinetics, and sensory profile of halved Hass avocados. A greater concentration of hydroalcoholic extracts increased the content of phenolic compounds and their antioxidant activity. As a result, the bands in the carboxylate groups of sodium alginate became more intense. Crystallinity decreased, whereas opacity and mass loss percentage increased, and conglomerates appeared on the surface of the films. These processes fit the KorsmeyerPeppas kinetic model because they resulted from a combination of diffusion and swelling mechanisms in the films. The films incorporated with hydroalcoholic extract of M. pyrifera proved to be an effective alternative to traditional fruit wrapping materials.

Bio-based antibacterial food packaging films and coatings containing cinnamaldehyde: A review

As a typical bioactive compound from the bark and leaves of the trees of the genus Cinnamomum, cinnamaldehyde (CIN) is natural and safe. Its excellent antibacterial activity against various foodborne microorganisms is growingly regarded as a promising additive for improving and enhancing the properties of bio-based packaging films/coatings. This review systematically summarized the bio-based food packaging films/coatings containing CIN developed recently. The effects of CIN incorporation on physical and chemical properties of the antibacterial food packaging films/coatings, including thickness, color index, transparency, water content, water solubility, water contact angle, mechanical performances, water barrier performances, and antibacterial performances, were discussed. Simultaneously, this work also concluded that an explanation of the antibacterial mechanism of CIN and preparation methods of bio-based packaging films/coatings containing CIN/CIN carriers. Notably, the incorporation of CIN into the films/coatings could enhance their antibacterial performance extend the shelf-life of various foods, such as fish, meats, vegetables, fruits, and other perishable food, while improving their physical and chemical properties. Although incorporating CIN into food packaging films/coatings has been extensively studied, long-term follow-up research on the human safety of active food packaging films/coatings containing CIN needs to be carried out.