Characterization of chrysanthemum essential oil triple-layer liposomes and its application against Campylobacter jejuni on chicken

Recent progress in the source, extraction, activity mechanism and encapsulation of bioactive essential oils

There is growing concern about the potential risks posed by synthetic additives in industrial products, such as foods, cosmetics, agrochemicals, and personal care products. Many plant-derived essential oils (EOs) have been shown to exhibit excellent antibacterial, antifungal, antiviral, and antioxidant activities, and may therefore be used as natural preservatives in these applications. However, most EOs have relatively low water solubility and are prone to chemical degradation during storage. The degradation products of EOs can be toxic and may not be able to fully exert their biological activity, which limits their application. Typically, these challenges can be overcome by encapsulating the essential oil in an appropriate colloid delivery system. This article begins by reviewing the sources, extraction, and activity mechanisms of EOs, and then highlights plant-based encapsulation technologies that can be used to enhance their efficacy. Finally, the potential applications of plant essential oil encapsulation system are discussed.

Encapsulation of lemongrass essential oil by bilayer liposomes based on pectin, gum Arabic, and carrageenan: Characterization and application in chicken meat preservation

The volatile characteristics of lemongrass essential oil (LO) have seriously hindered its further application, and encapsulation it with multilayer modified liposomes may be an effective strategy to improve this dilemma. This study selected chitosan (CH) and three anionic polymers, pectin (P) / gum arabic (GA) / carrageenan (C), as the first and second coating polymers to modify nano liposomes (NL) by layer-by-layer electrostatic deposition, obtaining three bilayer liposomes, P-CH-NL, GA-CH-NL, and C-CH-NL as high-quality stabilized carriers of LO. The bilayer liposomes showed a dense membrane structure ranging from 110 to 150 nm uniformly, with good antioxidant properties. All bilayer liposomes had good stability during 28-day storage at 4 °C, while C-CH-NL performed relatively better inferred by smaller changes of size, PDI and Zeta potential. The total volatile base nitrogen (TVB-N) values of fresh chicken meat and a total number of bacterial colonies (TBC) experiments showed that GA-CH-NL and C-CH-NL could better retard the increase of volatile salt base nitrogen. All bilayer liposomes could delay the time for the total bacterial count to exceed 6 log CFU/g (from 7 days to 10 / 12 days). Therefore, the bilayer liposomes P-CH-NL, GA-CH-NL, and C-CH-NL may be promising natural preservatives for food products.

Harnessing medicinal plant compounds for the control of Campylobacter in foods: a comprehensive review

Campylobacter is a major foodborne and zoonotic pathogen, causing severe human infections and imposing a substantial economic burden on global public health. The ongoing spread and emergence of multidrug-resistant (MDR) strains across various fields exacerbate therapeutic challenges, raising the incidence of diseases and fatalities. Medicinal plants, renowned for their abundance in secondary metabolites, exhibit proven efficacy in inhibiting various foodborne and zoonotic pathogens, presenting sustainable alternatives to ensure food safety. This review aims to synthesize recent insights from peer-reviewed journals on the epidemiology and antimicrobial resistance of Campylobacter species, elucidate the in vitro antibacterial activity of medicinal plant compounds against Campylobacter by delineating underlying mechanisms, and explore the application of these compounds in controlling Campylobacter in food. Additionally, we discuss recent advancements and future prospects of employing medicinal plant compounds in food products to mitigate foodborne pathogens, particularly Campylobacter. In conclusion, we argue that medicinal plant compounds can be used as effective and sustainable sources for developing new antimicrobial alternatives to counteract the dissemination of MDR Campylobacter strains.

Antibacterial effect of protease-responsive cationic eugenol liposomes modified by gamma-polyglutamic acid against Staphylococcus aureus

Eugenol, as a natural antibacterial agent, has been widely studied for its inhibitory effect on the common food-borne pathogen Staphylococcus aureus (S. aureus). However, the widespread application of eugenol is still limited by its instability and volatility. Herein, γ-polyglutamic acid coated eugenol cationic liposomes (pGA-ECLPs) were successfully constructed by self-assembly with an average particle size of 170.7 nm and an encapsulation efficiency of 36.2%. The formation of pGA shell significantly improved the stability of liposomes, and the encapsulation efficiency of eugenol only decreased by 20.7% after 30 days of storage at 4 °C. On the other hand, the pGA layer can be hydrolyzed by S. aureus, achieving effective control of release through response to bacterial stimuli. The application experiments further confirmed that pGA-ECLPs effectively prolonged the antibacterial effect of eugenol in fresh chicken without causing obvious sensory effects on the food. The above results of this study provide an important reference for extending the action time of natural antibacterial substances and developing new stimuli-responsive antibacterial systems.

Recent advances in essential oils and their nanoformulations for poultry feed

Antibiotics in poultry feed to boost growth performance are becoming increasingly contentious due to concerns over antimicrobial resistance development. Essential oils (EOs), as natural, plant-derived compounds, have demonstrated antimicrobial and antioxidant properties. EOs may potentially improve poultry health and growth performance when included in poultry feed. Nevertheless, the incorporation of EOs as nutritional additives is hindered by their high volatility, low water solubility, poor intestinal absorption, and sensitivity to environmental conditions. Recently, nanoencapsulation strategies using nanoformulations have emerged as a potential solution to these challenges, improving the stability and bioavailability of EOs, and enabling targeted delivery in poultry feed. This review provides an overview of the antioxidant and antibacterial properties of EOs, the current limitations of their applications in poultry feed, and the recent advancements in nano-engineering to overcome these limitations. Furthermore, we outline the potential future research direction on EO nanoformulations, emphasizing their promising role in advancing sustainable poultry nutrition.Highlights• Essential oils (EOs) are known as powerful antioxidants and antibacterial agents.• EOs have a high potential to replace antibiotics as feed additives.• Nanoformulations of EOs have shown improved bioactivity and storage stability of EOs.• Nanoformulation promotes the bioavailability and gut adsorption of EOs as feed additives.

Microencapsulation to Harness the Antimicrobial Potential of Essential Oils and Their Applicability in Dairy Products: A Comprehensive Review of the Literature

This literature review explores cutting-edge microencapsulation techniques designed to enhance the antimicrobial efficacy of essential oils in dairy products. As consumer demand for natural preservatives rises, understanding the latest advancements in microencapsulation becomes crucial for improving the shelf life and safety of these products. The bibliometric analysis utilized in this review highlighted a large number of documents published on this topic in relation to the following keywords: essential oils, AND antimicrobials, AND dairy products, OR microencapsulation. The documents published in the last 11 years, between 2013 and 2023, showed a diversity of authors and countries researching this topic and the keywords commonly used. However, in the literature consulted, no study was identified that was based on bibliometric analysis and that critically evaluated the microencapsulation of essential oils and their antimicrobial potential in dairy products. This review synthesizes findings from diverse studies, shedding light on the various encapsulation methods employed and their impact on preserving the quality of dairy goods. Additionally, it discusses the potential applications and challenges associated with implementation in the dairy industry. This comprehensive analysis aims to provide valuable insights for researchers, food scientists, and industry professionals seeking to optimize the use of essential oils with antimicrobial properties in dairy formulations.

Liposomes as Carriers of Bioactive Compounds in Human Nutrition

This article provides an overview of the literature data on the role of liposomal structures and encapsulated substances in food technology and human nutrition. The paper briefly describes how liposomes are created and how they encapsulate food ingredients, which can either be individual compounds or plant extracts. Another very interesting application of liposomes is their use as antimicrobial carriers to protect food products from spoilage during storage. The encapsulation of food ingredients in liposomes can increase their bioavailability, which is particularly important for compounds with health-promoting properties but low bioavailability. Particular attention was paid to compounds such as phytosterols, which lower blood cholesterol levels but have very low absorption in the human body. In addition, consumer expectations and regulations for liposomes in food are discussed. To date, no in vivo human studies have been conducted to indicate which encapsulation methods give the best results for gastrointestinal effects and which food-added substances are most stable during food storage and processing. The paper identifies further lines of research that are needed before liposomes can be introduced into food.

Degradable chitosan-based bioplastic packaging: Design, preparation and applications

Food packaging is an essential part of food transportation, storage and preservation. Biodegradable biopolymers are a significant direction for the future development of food packaging materials. As a natural biological polysaccharide, chitosan has been widely concerned by researchers in the field of food packaging due to its excellent film-forming property, good antibacterial property and designability. Thus, the application research of chitosan-based food packaging films, coatings and aerogels has been greatly developed. In this review, recent advances on chitosan-based food packaging materials are summarized. Firstly, the development background of chitosan-based packaging materials was described, and then chitosan itself was introduced. In addition, the design, preparation and applications of films, coatings and aerogels in chitosan-based packaging for food preservation were discussed, and the advantages and disadvantages of each research in the development of chitosan-based packaging materials were analyzed. Finally, the application prospects, challenges and suggestions for solving the problems of chitosan-based packaging are summarized and prospected.

Chitosan/alginate/pectin biopolymer-based Nanoemulsions for improving the shelf life of refrigerated chicken breast

This study investigated the use of nanoemulsions and various polymer coatings to enhance the quality and shelf life of chicken breast. This comprehensive study explored the antibacterial activity of essential oils (EOs) against Escherichia coli and Staphylococcus aureus, as well as the characterization of nanoemulsions (Nes) and nanoemulsion-based coatings. The antimicrobial potential of EOs, such as cinnamon, tea tree, jojoba, thyme, and black cumin seed oil, was evaluated against microorganisms, and thyme oil exhibited the highest inhibitory effect, followed by cinnamon and tea tree oil by disk diffusion analysis. The MIC and MBC values of EOs were found between 0.16-2.5 mg/mL and 0.16-5 mg/mL, respectively, while thyme EO resulted in the lowest values showing its antimicrobial potential. Then, the essential oil nanoemulsions (EONe) and their coatings, formulated with thyme oil, alginate, chitosan, and pectin, were successfully characterized. Optical microscope observations confirmed the uniform distribution of droplets in all (EONe), while particle size analysis demonstrated multimodal droplet size distributions. The EONe-chitosan coating showed the highest efficacy in reducing cooking loss, while the EONe-chitosan, EONe-alginate, and EONe-pectin coatings displayed promising outcomes in preserving color stability. Microbial analysis revealed the significant inhibitory effects of the EONe-chitosan coating against mesophilic bacteria, psychrophilic bacteria, and yeasts, leading to an extended shelf life of chicken breast. These results suggest the potential application of thyme oil and NE-based coatings in various industries for antimicrobial activity and quality preservation.

Enhancement of liposomal properties of thyme essential oil using lysozyme modification: Physicochemical, storage, and antibacterial properties

Thyme essential oil (TEO) is a natural food antimicrobial agent derived of spice, but suffers from volatility and poor water solubility, which problem can be effectively solved by the encapsulation of liposomes. On this basis, a safe and common natural antibacterial protein, LYZ was used to modify the TEO liposomes (TEO-lips) for gaining better properties. 2.5 mg/mL TEO and 0.05 % LYZ/S100 mass ratio were the best formula for the preparation of LYZ-TEO-lips. After LYZ modification, the particle size and PDI increased, and the zeta potential decreased slightly. The modification of LYZ not only improves the thermal stability of TEO-Lips, weakens the influence of acid and salt ions on liposomes, but also improves the antibacterial properties of TEO-Lips. In brief, LYZ has the potential to improve the overall properties of liposomes and can provide a reference for the development of antimicrobial liposomes.

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.

Current State of Knowledge Regarding WHO High Priority Pathogens-Resistance Mechanisms and Proposed Solutions through Candidates Such as Essential Oils: A Systematic Review

Combating antimicrobial resistance (AMR) is among the 10 global health issues identified by the World Health Organization (WHO) in 2021. While AMR is a naturally occurring process, the inappropriate use of antibiotics in different settings and legislative gaps has led to its rapid progression. As a result, AMR has grown into a serious global menace that impacts not only humans but also animals and, ultimately, the entire environment. Thus, effective prophylactic measures, as well as more potent and non-toxic antimicrobial agents, are pressingly needed. The antimicrobial activity of essential oils (EOs) is supported by consistent research in the field. Although EOs have been used for centuries, they are newcomers when it comes to managing infections in clinical settings; it is mainly because methodological settings are largely non-overlapping and there are insufficient data regarding EOs' in vivo activity and toxicity. This review considers the concept of AMR and its main determinants, the modality by which the issue has been globally addressed and the potential of EOs as alternative or auxiliary therapy. The focus is shifted towards the pathogenesis, mechanism of resistance and activity of several EOs against the six high priority pathogens listed by WHO in 2017, for which new therapeutic solutions are pressingly required.

Enhancing the targeting performance and prolonging the antibacterial effects of clove essential oil liposomes to Campylobacter jejuni by antibody modification

The application of plant essential oil liposomes to prevent and control food safety risks caused by Campylobacter jejuni (C. jejuni) still faces challenges such as lack of targeting and low release rate. Here, a bacteria-targeted and protease-activated antibacterial liposome (ACCLPs) was successfully synthesized through encapsulation of clove essential oil (CEO) by film dispersion method, embedding of casein by freeze-thaw method, and conjugation of C. jejuni antibody on the liposome membrane by post-insertion method. The average particle size, the essential oil encapsulation rate, the casein mosaic rate, and the antibody coupling efficiency of ACCLPs were determined as185.87 nm,16.9%,70.1% and 87.5%, respectively. The modification with C. jejuni antibody could significantly improve the targeting of ACCLPs to C. jejuni. Controlled release experiments showed that the exocrine protease from C. jejuni could hydrolyze the embedded casein and perforation on the ACCLPs, thus leading to a bacteria-dependent CEO release and significant prolonging the antibacterial effects of ACCLPs. Application results of ACCLPs on C. jejuni-contaminated foods showed that ACCLPs could effectively inhibit C. jejuni in a variety of meat products, fruits and vegetables and extend their shelf life without significantly affecting food quality. The results above in this work would provide a new view for the development of high efficient liposome-based antibacterial system of plant essential oil.

Advances in enteropathogen control throughout the meat chicken production chain

Enteropathogens, namely Salmonella and Campylobacter, are a concern in global public health and have been attributed in numerous risk assessments to a poultry source. During the last decade, a large body of research addressing this problem has been published. The literature reviewed contains review articles on certain aspects of poultry production chain; however, in the past decade there has not been a review on the entire chain-farm to fork-of poultry production. For this review, a pool of 514 articles were selected for relevance via a systematic screening process (from >7500 original search articles). These studies identified a diversity of management and intervention strategies for the elimination or reduction of enteropathogens in poultry production. Many studies were laboratory or limited field trials with implementation in true commercial operations being problematic. Entities considering using commercial antienteropathogen products and interventions are advised to perform an internal validation and fit-for-purpose trial as Salmonella and Campylobacter serovars and biovars may have regional diversity. Future research should focus on nonchemical application within the processing plant and how a combination of synergisticinterventions through the production chain may contribute to reducing the overall carcass burden of enteropathogens, coupled with increased consumer education on safe handling and cooking of poultry.

Nanoliposomal delivery systems of natural antibacterial compounds; properties, applications, and recent advances

Todays, nanoliposomes (NLPs) are considered as one of the most efficient nanocarriers to deal with bacteria, practically in food products. These nanodelivery systems are able to be loaded with different bioactive compounds. The main aim of this review is investigating recent approaches (mostly from the years of 2018 to 2022) regarding development of nanoliposomal natural antibacterial compounds. In this regard, NLPs alone, combined with films, coatings, or fibers, and in coated forms are reviewed as advanced delivery systems of antibacterial substances. Moreover, a robust and comprehensive coverage of the morphological and physical properties of formulated NLPs as well as their interactions with antibacterial substances are discussed. The importance of NLPs to encapsulate antibacterial ingredients, advantages and drawbacks, antibacterial pathways of formulated NLPs, and comparison of them with pure antibacterial bioactive compounds are also explained.

Pheophorbide-a as a Light-Triggered Liposomal Switch: For the Controlled Release of Alpinia galanga (A. galanga) Essential Oil and Its Stability, Antioxidant, and Antibacterial Activity Assessment

In this study, Alpinia galanga essential oil liposomes (EO-Lip) were prepared with soybean lecithin and cholesterol as wall materials. A light-responsive liposome (EO-PLip) was designed for the controlled release of A. galanga oil based on the light-responsive properties of Pheophorbide-a. The dependence of Pheophorbide-a on illumination time was proved by UV spectroscopy. Characterization techniques such as UV spectroscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy demonstrated that the essential oils were successfully encapsulated in liposomes. Moreover, the particle size of EO-PLip was 166.30 nm, the polydispersity index was 0.22, the zeta potential was -49.50 mV, and the encapsulation efficiency was 30.83%. Both EO-Lip and EO-Plip have high sustained-release effects on essential oil and showed light-responsive release characteristics under infrared stimulation. The prepared liposomes had good storage stability at 4 °C for 28 d. EO-PLip showed excellent transient antioxidant and bacteriostatic properties based on the ability to respond to light and slow release. This EO-PLip provided a platform for essential oils and might be used as a potent and controllable solution.

Nano-vesicular carriers for bioactive compounds and their applications in food formulations

The most commonly used vesicular systems in the food industry include liposomes, niosomes, phytosomes, or transfersomes. This review focuses on showing how nano-vesicular carriers (NVCs) amend the properties of bioactive compounds (bioactives), making them suitable for food applications, especially functional foods. In this research, we elaborate on the question of whether bioactive-loaded NVCs affect various food aspects such as their antioxidant capacity, or sensory properties. This review also shows how NVCs improve the long-term release profile of bioactives during storage and at different pH values. Besides, the refinement of digestibility and bioaccessibility of diverse bioactives through NVCs in the gastrointestinal tract is elucidated. NVCs allow for stable vesicle formation (e.g. from anthocyanins) which reduces their cytotoxicity and proliferation of cancer cells, prolongs the release bioactives (e.g. d-limonene) with no critical burst, reduces the biofilm formation capacity of both Gram-positive/negative strains and their biofilm gene expression is down-regulated (in the case of tannic acid), low oxidation (e.g. iron) is endured when exposed to simulated gastric fluid, and unpleasant smell and taste are masked (in case of omega-3 fatty acids). After the incorporation of bioactive-loaded NVCs into food products, their antioxidant capacity is enhanced, maintaining high encapsulation efficiency and enduring pasteurization conditions, and they are not distinguished from control samples in sensory evaluation despite the reverse situation about free bioactives.

Liposomes as Delivery System for Applications in Meat Products

In the meat industry, microbial contamination, and lipid and protein oxidation are important factors for quality deterioration. Although natural preservatives have been widely used in various meat products, their biological activities are often reduced due to their volatility, instability, and easy degradation. Liposomes as an amphiphilic delivery system can be used to encapsulate food active compounds, which can improve their stability, promote antibacterial and antioxidant effects and further extend the shelf life of meat products. In this review, we mainly introduce liposomes and methods of their preparation including conventional and advanced techniques. Meanwhile, the main current applications of liposomes and biopolymer-liposome hybrid systems in meat preservation are presented.

Encapsulation of Essential Oils in Nanocarriers for Active Food Packaging

Active packaging improves a packaging system's effectiveness by actively integrating additional components into the packaging material or the headspace around the packaging. Consumer demand and awareness have grown enough to replace chemical agents with natural active agents. Essential oils (EOs) are extensively distributed throughout nature but at low levels and sometimes with poor recovery yields, which poses an issue with their application in food. Due to the instability of EOs when added directly into a food product, they require encapsulation before being added to a packaging matrix such as liposomes, solid-lipid nanoparticles, nano-emulsions, cyclodextrins, and nanostructured lipid nano-carriers. This article is focused on the encapsulation of EOs in different types of nanocarriers. Nanocarriers can improve the efficiency of active substances by providing protection, stability, and controlled and targeted release. The advantages of the many types of nanocarriers that contain active substances that can be used to make antibacterial and antioxidant biopolymeric-based active packaging are discussed. A nanocarrier-encapsulated EO enables the controlled release of oil, stabilizing the packaging for a longer duration.

Cationic inulin as a new surface decoration hydrocolloid for improving the stability of liposomal nanocarriers

The aim of the present study was to investigate the cationization of inulin with Williamson's etherification method, and compare cationic inulin with unmodified inulin coatings for stabilizing nanoliposomes (NLPs). The synthetized cationic inulin was characterized by Fourier transforms infrared (FT-IR) spectroscopy, carbon hydrogen nitrogen (CHN) elemental analysis, and energy-dispersive X-ray spectroscopy. Three concentrations of inulin and cationic inulin (1, 2, and 4 mg/mL) were used for the coating of NLPs. The concentration of 4 mg/mL was found to be optimal for inulin and cationic inulin as surface coating, on the basis of particle size, zeta potential, and microstructural morphology. The lowest values of particle size (93.41 nm), polydispersity index (0.25), and negative zeta potential (-24.41 mV) were related to the coated NLPs with cationic inulin at a concentration of 4 mg/mL. The transmission electron microscopy image of the coated NLPs with cationic inulin exhibited a spherical and core-shell structure. The coated NLPs with cationic inulin showed the highest thermal stability, physical stability, and oxidative stability. In conclusion, cationic inulin coating conferred a stronger protection than the unmodified inulin coating of NLPs. The technique developed here can be applied for surface decoration of NLPs to improve their stability.

Liposomal Delivery of Plant Bioactives Enhances Potency in Food Systems: A Review

The potency of plant bioactives may decline drastically upon exposure to harsh external environments including gastrointestinal conditions. The protective role played by liposomes contributes to desirable properties including increased stability, slow/controlled release, improved bioactivity, and enhanced bioavailability of the encapsulated bioactives. Also, the incorporation of plant bioactives encapsulated liposomes in food matrices has resulted in augmented sensory attributes and improved quality of the foods further exhibiting the aptness of liposomal applications in food. Excitingly, new opportunities that circumvent the major shortfalls of utilizing liposomal formulations in the food industry have arisen paving the way to yield food products with high quality.

The Analysis of Chitosan-Coated Nanovesicles Containing Erythromycin-Characterization and Biocompatibility in Mice

Nanoantibiotics have proved improved pharmacokinetic characteristics and antimicrobial features. Recent studies have shown non-toxicity, non-immunogenicity, antioxidant, anti-hyperlipidemic, and hepatocyte protective actions, among other advantages of chitosan-based nanoparticles. The purpose of our study was the structural analysis of novel chitosan-coated vesicles entrapping erythromycin (ERT) and the assessment of their biocompatibility in mice. According to the group in which they were randomly assigned, the mice were treated orally with one of the following: distilled water; chitosan; ERT; chitosan vesicles containing ERT. Original nanosystems entrapping ERT in liposomes stabilized with chitosan were designed. Their oral administration did not produce sizeable modifications in the percentages of the leukocyte formula elements, of some blood constants useful for evaluating the hepatic and renal function, respectively, and of some markers of oxidative stress and immune system activity, which suggests a good biocompatibility in mice. The histological examination did not reveal significant alterations of liver and kidney architecture in mice treated with chitosan liposomes entrapping ERT. The results indicate the designed liposomes are a promising approach to overcome disadvantages of conventional ERT treatments and to amplify their benefits and can be further studied as carrier systems.

Coating of betanin and carvone Co-loaded nanoliposomes with synthesized cationic inulin: A strategy for enhancing the stability and bioavailability

Betanin (BET) and carvone (CAR) as antioxidant and antibacterial compounds were co-loaded in the coated nanoliposomes (NLPs) with cationic inulin to improve their stability and bioavailability. A cationic inulin was successfully synthesized and used for surface coating of the NLPs. The zeta potential, particle size, and PDI values of the coated NLPs were 21.70 ± 7.00 mV, 143.5 ± 15.2 nm, and 0.35 ± 0.03 respectively. The encapsulation efficiency values of the coated NLPs for BE and CAR were 86.1 ± 3.9 and 77.2 ± 5.2 %, respectively. Electron microscopy results showed that the coated NLPs had spherical and core-shell structures. The slowest sustained release profile in the simulated gastrointestinal condition was obtained for the coated NLPs. The physical and oxidative stability of NLPs, as well as the physical stability of loaded compounds were improved by surface coating. In conclusion, the developed nanocarrier is a suitable platform to use all benefits of BET and CAR in the food industry.

Lipid-Based Nanostructures for the Delivery of Natural Antimicrobials

Encapsulation can be a suitable strategy to protect natural antimicrobial substances against some harsh conditions of processing and storage and to provide efficient formulations for antimicrobial delivery. Lipid-based nanostructures, including liposomes, solid lipid nanoparticles (SLNs), and nanostructured lipid nanocarriers (NLCs), are valuable systems for the delivery and controlled release of natural antimicrobial substances. These nanostructures have been used as carriers for bacteriocins and other antimicrobial peptides, antimicrobial enzymes, essential oils, and antimicrobial phytochemicals. Most studies are conducted with liposomes, although the potential of SLNs and NLCs as antimicrobial nanocarriers is not yet fully established. Some studies reveal that lipid-based formulations can be used for co-encapsulation of natural antimicrobials, improving their potential to control microbial pathogens.

Plant oils: From chemical composition to encapsulated form use

The last decade has witnessed a burgeoning global movement towards essential and vegetable oils in the food, agriculture, pharmaceutical, cosmetic, and textile industries thanks to their natural and safe status, broad acceptance by consumers, and versatile functional properties. However, efforts to develop new therapy or functional agents based on plant oils have met with challenges of limited stability and/or reduced efficacy. As a result, there has been increased research interest in the encapsulation of plant oils, whereby the nanocarriers serve as barrier between plant oils and the environment and control oil release leading to improved efficacy, reduced toxicity and enhanced patient compliance and convenience. In this review, special concern has been addressed to the encapsulation of essential and vegetable oils in three types of nanocarriers: polymeric nanoparticles, liposomes and solid lipid nanoparticles. First, the chemical composition of essential and vegetable oils was handled. Moreover, we gather together the research findings reported by the literature regarding the different techniques used to generate these nanocarriers with their significant findings. Finally, differences and similarities between these nanocarriers are discussed, along with current and future applications that are warranted by their structures and properties.

Biopolymer-liposome hybrid systems for controlled delivery of bioactive compounds: Recent advances

Conventional liposomes still face many challenges associated with the poor physical and chemical stability, considerable loss of encapsulated cargo, lack of stimulus responsiveness, and rapid elimination from blood circulation. Integration of versatile functional biopolymers has emerged as an attractive strategy to overcome the limitation of usage of liposomes. This review comprehensively summarizes the most recent studies (2015-2020) and their challenges aiming at the exploration of biopolymer-liposome hybrid systems, including surface-modified liposomes, biopolymer-incorporated liposomes, guest-in-cyclodextrin-in-liposome, liposome-in-hydrogel, liposome-in-film, and liposome-in-nanofiber. The physicochemical principles and key technical information underlying the combined strategies for the fabrication of polymeric liposomes, the advantages and limitations of each of the systems, and the stabilization mechanisms are discussed through various case studies. Special emphasis is directed toward the synergistic efficiencies of biopolymers and phospholipid bilayers on encapsulation, protection, and controlled delivery of bioactives (e.g., vitamins, carotenoids, phenolics, peptides, and other health-related compounds) for the biomedical, pharmaceutical, cosmetic, and functional food applications. The major challenges, opportunities, and possible further developments for future studies are also highlighted.

Advancements in liposome technology: Preparation techniques and applications in food, functional foods, and bioactive delivery: A review

Liposomes play a significant role in encapsulation of various bioactive compounds (BACs), including functional food ingredients to improve the stability of core. This technology can be used for promoting an effective application in functional food and nutraceuticals. Incorporation of traditional and emerging methods for the developments of liposome for loading BACs resulted in viable and stable liposome formulations for industrial applications. Thus, the advance technologies such as supercritical fluidic methods, microfluidization, ultrasonication with traditional methods are revisited. Liposomes loaded with plant and animal BACs have been introduced for functional food and nutraceutical applications. In general, application of liposome systems improves stability, delivery, and bioavailability of BACs in functional food systems and nutraceuticals. This review covers the current techniques and methodologies developed and practiced in liposomal preparation and application in functional foods.

Chitosan-Coating Effect on the Characteristics of Liposomes: A Focus on Bioactive Compounds and Essential Oils: A Review

In recent years, liposomes have gained increasing attention for their potential applications as drug delivery systems in the pharmaceutic, cosmetic and food industries. However, they have a tendency to aggregate and are sensitive to degradation caused by several factors, which may limit their effectiveness. A promising approach to improve liposomal stability is to modify liposomal surfaces by forming polymeric layers. Among natural polymers, chitosan has received great interest due to its biocompatibility and biodegradability. This review discussed the characteristics of this combined system, called chitosomes, in comparison to those of conventional liposomes. The coating of liposomes with chitosan or its derivatives improved liposome stability, provided sustained drug release and increased drug penetration across mucus layers. The mechanisms behind these results are highlighted in this paper. Alternative assembly of polyelectrolytes using alginate, sodium hyaluronate, or pectin with chitosan could further improve the liposomal characteristics. Chitosomal encapsulation could also ensure targeted delivery and boost the antimicrobial efficacy of essential oils (EOs). Moreover, chitosomes could be an efficient tool to overcome the major drawbacks related to the chemical properties of EOs (low water solubility, sensitivity to oxygen, light, heat, and humidity) and their poor bioavailability. Overall, chitosomes could be considered as a promising strategy to enlarge the use of liposomes.

Effect of Chitosan Coating Incorporated with Artemisia fragrans Essential Oil on Fresh Chicken Meat during Refrigerated Storage

The present study was conducted to assess the impact of chitosan coating (1%) containing Artemisia fragrans essential oil (500, 1000, and 1500 ppm) as antioxidant and antimicrobial agent on the quality properties and shelf life of chicken fillets during refrigerated storage. After packaging meat samples, physicochemical, microbiological, and organoleptic attributes were evaluated at 0, 3, 6, 9, and 12 days at 4 °C. The results revealed that applied chitosan (CH) coating in combination with Artemisia fragrans essential oils (AFEOs) had no significant (p < 0.05) effects on proximate composition among treatments. The results showed that the incorporation of AFEOs into CH coating significantly reduced (p < 0.05) pH, thiobarbituric acid reactive substances (TBARS), and total volatile base nitrogen (TVB-N), especially for 1% CH coating + 1500 ppm AFEOs, with values at the end of storage of 5.58, 1.61, and 2.53, respectively. The coated samples also displayed higher phenolic compounds than those obtained by uncoated samples. Coated chicken meat had, significantly (p < 0.05), the highest inhibitory effects against microbial growth. The counts of TVC (total viable counts), coliforms, molds, and yeasts were significantly lower (p < 0.05) in 1% CH coating + 1500 ppm AFEOs fillets (5.32, 3.87, and 4.27 Log CFU/g, respectively) at day 12. Organoleptic attributes of coated samples also showed the highest overall acceptability scores than uncoated ones. Therefore, the incorporation of AFEOs into CH coating could be effectively used for improving stability and shelf life of chicken fillets during refrigerated storage.

Edible flower essential oils: A review of chemical compositions, bioactivities, safety and applications in food preservation

In the context of consumers' growing concerns and boycotts of artificial and harmful chemicals, satisfying the demands for good-quality food products possessing clean and safe images is a challenge for food industry. Due to natural and avirulent images, various bioactivities as well as potentials to be used as safer substitutes for chemical preservatives, flower essential oils (EOs) have aroused increasing interests in the recent past. Many literatures have verified the biological activities of flower EOs, and have given high value to the preservative potentials of flower EOs in food systems. In this work, a review is done on the most recent publications associating the chemical constituents, bioactivities (antibacterial, antifungal, antioxidant and anti-pest abilities) and safety of flower EOs. The effects of flower EOs on food flavor are also discussed. Finally, the current combined preservation applications of flower EOs and other technologies are summarized.

Controlled-release casein/cinnamon essential oil nanospheres for the inactivation of Campylobacter jejuni in duck

Campylobacter jejuni (C. jejuni) is one of the most common foodborne pathogens that cause human sickness mostly through the poultry food chain. Cinnamon essential oil (CEO) has excellent antibacterial ability against C. jejuni growth. This study investigated the antibacterial mechanism of CEO against C. jejuni primarily through metabolism, energy metabolism of essential enzymes (AKPase, β-galactosidase, and ATPase), and respiration metabolism. Results showed that the hexose monophosphate pathway (HMP) was inhibited, and that the enzyme activity of G₆DPH substantially decreased upon treatment with CEO. Analysis of the effect of CEO on the expression of toxic genes was performed by the real-time PCR (RT-PCR). The expression levels of the toxic genes cadF, ciaB, fliA, and racR under CEO treatment were determined. Casein/CEO nanospheres were further prepared for the effective inhibition of C. jejuni and characterized by particle-size distribution, zeta-potential distribution, fluorescence, TEM, and GC-MS methods. Finally, the efficiency of CEO and casein/CEO nanospheres in terms of antibacterial activity against C. jejuni was verified. The casein/CEO nanospheres displayed high antibacterial activity on duck samples. The population of the test group decreased from 4.30 logCFU/g to 0.86 logCFU/g and 4.30 logCFU/g to 2.46 logCFU/g at 4 °C and at 25 °C for C. jejuni, respectively. Sensory evaluation and texture analysis were also conducted on various duck samples.

Nanoemulsion of Minthostachys verticillata essential oil. In-vitro evaluation of its antibacterial activity

Infectious diseases constitute a problem of great importance for animal and human health, as well as the increasing bacterial resistance to antibiotics. In this context, medicinal plants emerge as an effective alternative to replace the use antibiotics. The essential oil (EO) of Minthostachys verticillata (Griseb.) Epling (Lamiaceae) has demonstrated a strong antimicrobial activity. However, its instability and hydrophobicity under normal storage conditions are limitations to its use. Nanoemulsion technology is an excellent way to solubilize, microencapsulate, and protect this compound. This study aimed to obtain a nanoemulsion based on M. verticillata EO and evaluate its antibacterial activity against Staphylococcus aureus. The EO was obtained by steam distillation. Identification and quantification of their components were determined by GC-MS revealing that the dominated chemical group was oxygenated monoterpenes. Nanoemulsions (NE) were characterized by measuring pH, transmittance, separation percentage, release profile, and morphology. The effect of NE on the growth of S. aureus and cyto-compatibility was also evaluated. The results showed that NE containing a higher percentage of tween 20 exhibited higher stability with an approximated droplet size of 10 nm. The effect of encapsulation process was evaluated by GC-MS revealing that the volatile components in EO were no affected. After 24 h, 74.24 ± 0.75% of EO was released from NE and the antibacterial activity of EO was enhanced considerably by its encapsulation. The incubation of S. aureus with the NE and pure EO, show a bacterial growth inhibition of 58.87% ± 0.99 and 46.72% ± 3.32 (p < 0.05), respectively. In addition, nanoemulsión did not cause toxicity to porcine and equine red blood cells. The results obtained showed that NE could be a potential vehicle for M. verticillata EO with promissory properties to emerge as a tool for developing advanced therapies to control and combat infections.

Liposomal nanodelivery systems generated from proliposomes for pollen extract with improved solubility and in vitro bioaccessibility

This study offers a suitable and easy proliposome-liposome method that enhances the encapsulation ability of liposome structures on poor water-soluble extracts. Pollen phenolic extract (PPE) was studied to show applicability in the proposed method. The poor water-soluble PPE (0.2%, w/v) was encapsulated by liposomes generated from proliposomes (P-liposomes) that were prepared via high-pressure homogenization technique without using any organic solvents and high temperature. Only a few drops of ethanol were used to dissolve poor water-soluble compounds in PPE during the preparation of P-liposomes. The trace amount of ethanol maintained the improvement of PPE solubility in P-liposome dispersion, hence the in vitro bioaccessibility and bioactivity of PPE incorporated in P-liposomes increased. Thus, higher encapsulation efficiency was found in P-liposomes compared to conventional liposomes (C-liposomes) in which the EE was 75 and 73%, respectively. To increase the physical stability of liposome structures, the surface of both P-liposomes and C-liposomes was covered with chitosan. There were found small changes between P-liposomes and C-liposomes in terms of mean diameter size and zeta potential. On the other hand, the bioactivity of encapsulated PPE showed differences in P-liposomes and C-liposomes. The antioxidant capacity of PPE in P-liposomes enhanced approximately two times in CUPRAC and three times in DPPH assays. Also, in vitro bioaccessibility of PPE in P-liposomes increased approximately 4 and 2 folds, respectively, regarding total phenolics and flavonoids. To our knowledge, this is the first report about the increment of encapsulation behavior of liposome structures on low water-soluble extract within an aqueous media.