Microencapsulation of juniper berry essential oil (Juniperus communis L.) by spray drying: microcapsule characterization and release kinetics of the oil

Foam-based mustard essential oil microcapsules preparation, characterization, grilling application and comparison with emulsion microcapsules

Emulsion-based microencapsulation is the dominant form of encapsulating target components. Foam of emulsions is a neglected and important form of encapsulation due to its lower substance content, large specific surface area, and stable water-oil emulsion interface, which is equally feasible for drying and encapsulation. In this study, using the encapsulation of a small amount of mustard essential oil (MEO) as an example, the differences in physicochemical properties between foam-based and emulsion-based MEO microcapsules were evaluated by preparing protein (soybean isolate protein) and polysaccharide (sodium alginate) emulsion systems with a high amount of foaming, collecting the foams and drying (hot air drying and freeze-drying). The effects of the powders on barbecue seasoning were also tested on this basis. By comparison, the foam microcapsules have an irregular micro-particle structure, particle size, and differences in wall properties, leading to significant differences in particle surface oil content, water solubility, flowability, and release characteristics. Still, the microcapsules all provide enhancement in the seasoning of roasted meat. Moreover, by image tracing and contouring of the microstructure, the distribution relationship of the components in the foam microcapsules was also explained. These discussions provide a new insight into the preparation and application of foam microcapsules.

Microcapsules stabilized by cellulose nanofibrils/whey protein complexes and modified with cinnamaldehyde: Characterization and release properties

This work aims to optimize encapsulation of Zanthoxylum schinifolium essential oil (ZSEO) in microcapsule to enhance its stability and slow-release capability. Herein, the ZSEO microcapsules stabilized by bacterial cellulose nanofibrils/whey protein isolate (BCNFs/WPI) complexes and modified by cinnamaldehyde (CA) were successfully prepared via spray drying. The microcapsules formed by 1.0 wt% BCNFs/WPI complexes at a ratio of 1:7 and fortified with 0.7 wt% CA, exhibited superior physical properties, a smaller powder size and the highest encapsulation efficiency (90.81 %). The spectroscopy analysis and molecular dynamics simulations demonstrated the presence of hydrogen bonding and electrostatic interactions between CA and BCNFs/WPI/ZSEO components, contributing to an increase in the binding energy. The release kinetic modeling revealed that the microcapsules exhibited the delayed release capability in both aqueous and oily model fluids. Moreover, the ZSEO microcapsules modified with CA exhibited enhanced stability during in vitro digestion, offering valuable insights into the microencapsulation of essential oils.

Advances in Microencapsulation of Flavor Substances: Preparation Techniques, Wall Material Selection, Characterization Methods, and Applications

This review systematically examines advances in flavor microencapsulation technology from 2014 to 2024, focusing on innovations in preparation techniques, trends in wall material selection, and characterization methods. Literature metrological analysis shows that spray drying is the predominant technology (25% of reports); its shortcomings in volatile flavor retention have driven improved strategies such as vacuum low-temperature drying, ultrasound assistance, and monodisperse atomization. Emerging technologies such as electrohydrodynamic methods (electrospinning/electrospraying) and supercritical fluid processing are favored due to their nonthermal advantages. Overall, traditional polysaccharides have been widely used due to their good emulsifying and stabilizing properties. In the meanwhile, plant-based polysaccharides (e.g., inulin, hemicellulose) and proteins (e.g., pea protein) are increasingly preferred as the wall materials driven by sustainability and clean-labeling requirements. Morphological analysis and particle size and distribution studies have highlighted the key role of microstructure in stability and release kinetics, with multicore and multishell structures optimizing controlled release performance. Despite progress, gaps remain in the standardized assessment of encapsulation efficacy, the cost-effectiveness of novel materials, and practical food applications. In the future, a combination of interdisciplinary approaches is needed to investigate low-energy preparation technologies, functionalized wall materials, and intelligent release mechanisms to achieve the better application of flavor microencapsulates in food.

Preparation of Cinnamomum camphora essential oil microcapsules using gelatin/gum arabic and evaluation of their antifungal effects on Fusarium spp

We developed a complex coacervation method of preparing Cinnamomum camphora essential oil (CEO) microcapsules using gelatin and gum arabic as wall materials. The microencapsulation process was optimized using Plackett-Burman and Box-Behnken designs with a maximum yield of 84.48 ± 3.15 % and encapsulation efficiency of 91.89 ± 2.71 %. The thermogravimetric analysis demonstrated that the microencapsulation process clearly enhanced the thermal stability of the CEO, and assessment of their controlled-release ability revealed that the release mechanism of the microcapsules resembled diffusion. The CEO microcapsules exhibited effective antifungal activity against Fusarium culmorum and Fusarium sporotrichioides, and the inhibitory effect was highly correlated with the fumigation concentration of the microcapsules. This study provides valuable information for utilizing microcapsule carriers to deliver CEO as well as improve its preservation stability, which will broaden the applications of the CEO in the agricultural and food preservation industries.

Stability of probiotic microcapsules produced through complex coacervation based on whey protein-gum arabic coupled with double emulsification: Role of krill oil in middle oil phase

The objective of this study was to prepare a microcapsule system composed of the inner microenvironment (probiotics), middle oil layer (soybean oil and polyglycerol polyricinoleate) and outer coacervate (whey protein and gum arabic) using double emulsification technique coupled with complex coacervation to encapsulate probiotics, and to evaluate the effect of adding krill oil (KO) to the middle oil layer on microcapsule structure and probiotic stability. The results of Fourier transform infrared spectroscopy and Scanning electron microscopy confirmed that whey protein may capture phospholipids in KO through hydrogen bonds, resulting in the formation of a more compact coacervate. Due to the compact coacervate enhanced the vapor transport barrier and reduced water evaporation during low-temperature dehydration, probiotics encapsulated in KO-supplemented microcapsules revealed less cell damage and a higher survival rate after freeze-drying. More importantly, compared with KO-free microcapsules, KO-supplemented microcapsules provided better protection for probiotics under environmental stress (pasteurization, storage and simulated gastrointestinal tract), and the protection degree exhibited a "dose-effect" relationship with the KO content (0-15 %). Overall, this work provides a novel strategy for the design of microcapsules with high bacterial viability.

Cinnamon essential oil -loaded bagasse cellulose/hydroxypropyl-β-cyclodextrin microparticles with sustained-release property and its application in grapes preservation

This study investigate the feasibility of cinnamon essential oil-loaded bagasse cellulose/hydroxypropyl-β-cyclodextrin (CEO/BC/HP-β-CD) microparticles with sustained-release, using BC and HP-β-CD as co-encapsulation agents. CEO/BC/HP-β-CD was prepared by simple and easy-to-operate methods. The SEM confirms that it has a dense flocculent structure, and CEO is fixed to form a three-dimensional (3-D) network and stably arranged. The FTIR and XRD show that the co-cross-links among CEO, BC and HP-β-CD form inclusion complexes. 18 days (25 °C), different humidity and different light intensities of stability experiments show that the co-encapsulation of HP-β-CD and BC can significantly improve the low stability and control the release of CEO. On the antibacterial test, the diameter of inhibition zone of CEO/BC/HP-β-CD is significantly larger than that of CEO (180 mm, and 112 mm). To evaluate the preservation effect, grapes were treated with blank, 0.1 ml /kg CEO, 1.85 g/kg CEO/ HP-β-CD and 2.5 g/kg CEO/ HP-β-CD. Compared with blank, CEO/BC/ HP-β-CD significantly reduce the shedding rate (reductions of 33.97 %), delay the decrease of TSS, DPPH and VC content (delay of 42.95 %, 22.73 % and 44.51 %). Compare with CEO, CEO/BC/ HP-β-CD has a long-term preservation effect and mask strong small. This study improves the utilization value of BC, provides a new method for grape preservation.

Enhancing the stability of spray-dried vitamin A acetate: the role of synergistic wall materials in microencapsulation

BACKGROUND

Vitamin A is a fat-soluble vitamin that is susceptible to environmental factors, which can result in reduced activity. The stability of vitamins directly affects the shelf life and market competitiveness of products in the nutrient-fortified foods/drugs sector. Encapsulation via emulsion spray drying is a commonly utilized method to enhance the stability of active substances. It boasts a wide range of applications and capability for automated and continuous production. The wall material of microcapsules represents one of the pivotal factors influencing their properties, potentially mitigating the degradation of active substances during storage.

RESULTS

This study aimed to investigate the characteristics of vitamin A acetate (VAA) high-loading-capacity emulsions and microcapsules formulated with different encapsulating agents (gum arabic (GA), gelatin (GEL), white sugar (WS) and octenyl succinic acid-modified starch) prepared by spray drying. According to the accelerated storage experiment formula, the shelf life of microcapsules stored at 60 °C for 35 days is about 1 year, and the retention rate of GA + GEL/WS microcapsules with a loading capacity of 100 g kg-1 reaches over 90%. The performance of microcapsules with different wall materials was investigated and the reasons for the enhanced stability through the interaction between wall materials were analyzed.

CONCLUSION

The results showed that spray drying of microcapsules improved the water solubility and storage stability of VAA. At high loading levels, the synergistic effect between wall materials can improve the density of microcapsules, thereby enhancing the storage stability of VAA microcapsules. Such higher storage stability is beneficial for extending the shelf life of fortified foods and pharmaceuticals, thereby expanding the application of VAA in the food sector. © 2025 Society of Chemical Industry.

Preparation of Eugenol-Thymol-Cuminal Composite Essential Oil Microcapsules with AITC & β-Cyclodextrin Inclusion Complex and Its Effect on Quality of Chilled Pork

The preservation of chilled fresh pork is an issue that has widely drawn significant attention. A novel microcapsule was developed in this study, specifically a composite plant essential oil microcapsule (CEO mps) prepared using gum arabic (GA) and an inclusion compound of allyl isothiocyanate (AITC) with β-cyclodextrin (β-CD), in which AITC is encapsulated within the cavity of β-CD molecules. In this formulation, AITC functions as an antibacterial agent, while the essential oils provide antioxidant properties that further enhance bacterial inhibition. The encapsulation ratio of AITC to β-CD was optimized at 1:1, with nuclear magnetic resonance (NMR) hydrogen spectroscopy confirming that AITC was incorporated into β-CD through its wider cavity. The morphology and structure of CEO mps were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and laser particle size analysis, and these were compared to those of AITC mps-microcapsules prepared with GA and β-CD as wall materials and AITC as the core material. The results indicated that CEO mps exhibited superior appearance and physical stability in comparison to AITC mps. The release rate of CEO mps was evaluated using gas chromatography-mass spectrometry (GC/MS), revealing sustained release characteristics. On day 12, cumulative releases for AITC, eugenol, cuminal, and thymol were 61.82%, 57.96%, 44.34%, and 38.65%. Finally, the efficacy of CEO mps in preserving chilled pork was assessed by measuring pH levels, total volatile base nitrogen (TVB-N), color parameters (L*, a*, b*), thiobarbituric acid-reactive substances (TBARSs), water loss, and total microbial counts. The results demonstrated that CEO mps significantly inhibited microbial growth in chilled pork, reduced TBARS and TVB-N values, and helped preserve meat color integrity, thereby effectively extending shelf life by approximately six days. Overall, the experimental findings confirmed that the developed CEO mps possess both antibacterial and antioxidant properties, thereby improving both the shelf life and organoleptic quality of chilled pork.

A chemical and physical encapsulation technique for cinnamaldehyde in oleogel: Sustained-release, antibacterial activity, and preservation for orah mandarin

Cinnamaldehyde (CA), as a natural antibacterial agent, manifests robust antimicrobial properties and remarkable safety profiles. However, its high volatility and susceptibility to oxidation limit its widespread application, particularly in fields requiring long-lasting antibacterial activity. In this study, the sustained and long-term release of CA was achieved by developing a simple oleogel system consisting of CA, 12-hydroxystearic acid (12-HSA), and flaxseed oil (FSO). Comparative test of antibacterial performance over 40 days and the preservation of orah mandarin demonstrated the effectiveness of the oleogel system on the long-term and controllable release of CA. In addition to the blocking effect of hydrogen bond network structure commonly formed in oleogel, a dynamic reversible covalent bond between CA and 12-HSA significantly contributed to the long-term release of CA. This research provides valuable insights to the use of small-molecule volatile plant essential oils to achieve green antibacterial and food preservation.

Antimicrobial and insecticidal activity of spray dried juniper berry (Juniperus communis L.) essential oil microcapsules prepared by using gum arabic and maltodextrin

This study was carried out to optimize spray drying conditions for juniper berry essential oil (JBEO) microencapsulation. The coating material for encapsulation was a combination of maltodextrin (MD) andgum arabic (GA). The wall material content, inlet air temperature and feed flow rate were optimized to obtain small particle size and high level of powder production, with high JBEO loading and encapsulation efficiency, small powder moisture and hygroscopicity. The optimal formulation was characterized by FTIR spectroscopy and used for investigation of antimicrobial and insecticidal activities. The obtained optimal conditions for JBEO microencapsulation were inlet air temperature of 140 °C, feed flow rate of 2.43 cm3 min-1 and wall/core ratio of 3:1. The considerably greater JBEO oil retention was obtained by using spray dried GA compared to GA in a form of the branched polysaccharide. Microencapsulated JBEO showed antibacterial and antifungal activities at oil concentrations 1-5 %. Strong repellency against S. oryzae and A. obtectus were achieved at concentration of JBEO of 2 %, while for mortality of 65.5 % (S. oryzae) and 85.5 % (A. obtectus) after 72 h, the 5 % of JBEO were required. JBEO microencapsulation could be a promising method for the production of biopesticides to reduce the use of chemical preparations.

Microcapsule Techniques to Emphasize Functional Plant Oil Quality and Their Applications in the Food Industry: A Review

Natural functional plant oils (FPOs) have been widely exploited due to their abundant biological activities. However, when exposed to oxygen, light, moisture, and heat, some limitations such as oxidative deterioration, impaired flavor, loss of nutritional value and volatile compounds, and decreased shelf life hinder the widespread application of FPOs in the food industry. Notably, the microencapsulation technique is one of the advanced technologies, which has been used to maintain the biological and physicochemical properties of FPOs. The present review provided a comprehensive overview of the nutrient compositions and functionality of FPOs, preparation techniques for microcapsules, and applications of microencapsulated FPOs (MFPOs) in the food industry. FPOs obtained from a wide range of sources were abundant in bioactive compounds and possessed disease risk mitigation and improved human health properties. The preparation methods of microencapsulation technology included physical, chemical, and physicochemical methods, which had the ability to enhance oxidative stability, functional, shelf life, and thermostability properties of FPOs. In this context, MFPOs had been applied as a fortification in sausage, meat, bakery, and flour products. Overall, this work will provide information for academic fields and industries the further exploration of food and nutriment products.

Long-acting sustained release microcapsules of oregano essential oil-loaded gelatin/carrageenan for food preservation against Botrytis cinerea

As a food-derived natural component, oregano essential oil (OEO) exhibits excellent activity against Botrytis cinerea (B. cinerea). However, its poor water solubility and chemical instability limit its application in preservation. In this study, we determined the composition of OEO and encapsulated it in microcapsules using gelatin/carrageenan (GE/CRG) as the capsule wall, achieving a particle size of 336.10 nm and an encapsulation efficiency of 87.79 %. The microcapsules realize the slow-release duration of OEO to over 80 h. More importantly, due to the slow-release effect of OEO, OEO-GE/CRG microcapsules demonstrated excellent inhibitory activity against B. cinerea with an EC50 value of 0.18 mg/mL. The microcapsule treatment significantly prolonged the preservation period of cherry tomatoes in infection models with B. cinerea. These results indicate that OEO-GE/CRG microcapsules could serve as a potential fungal inhibitor and agent for fruit storage and preservation.

Effect of the addition of Chachafruto flour on the stability of oil-in-water emulsions and the physicochemical properties of spray-drying microcapsules

This study aimed to assess the suitability of Chachafruto flour (CHF) as a stabilizing agent for an oil-in-water emulsion and its impact on the physicochemical properties of the emulsion after spray drying. Emulsions with varying CHF concentrations (2 %, 3 %, and 4 %) were prepared and compared to a control. The results from the creaming index and particle size (emulsion) analyses indicated that the highest emulsion stability was achieved with 4 %CHF, attributed to its protein content (20.5 %). The encapsulates exhibited spherical and rough surface morphologies but without holes on the surface. Low moisture content (MC < 5 %) and water activity (aw < 0.2) were associated with powder stability. The encapsulates added with CHF showed good reconstitution properties. FTIR confirmed the absence of chemical interactions during the encapsulation process, contributing to the stability. Furthermore, the addition of CHF improved the thermal stability of the encapsulates. This study represents the first investigation on the emulsifying potential of Chachafruto flour.

Recent updates of carotenoid encapsulation by spray-drying technique

Carotenoids are compounds sensitive to environmental factors such as light, heat, and oxygen, which can result in the loss of their properties due to isomerisation and oxidation. To overcome this problem, spray drying encapsulation has been widely used as a method to protect and stabilise carotenoids in different wall materials. This article summarises the findings and research on spray drying encapsulation of carotenoids over the past 15 years, with an emphasis on the importance of controlling the operational conditions of the drying process and the association of different wall materials (proteins and polysaccharides), promising to increase encapsulation efficiency and stabilise carotenoids, with perspectives and trends in applications. The use of spray drying for carotenoid microencapsulation can open up new opportunities for controlled delivery of beneficial compounds. Based on the study, it is expected to provide information for researchers, professionals, and companies interested in the development of functional food products.

Development and Characterization of Potato Starch-Pectin-Based Active Films Enriched With Juniper Berry Essential Oil for Food Packaging Applications

The increasing demand for sustainable food packaging has driven the development of films based on biopolymers. However, enhancing their functional properties remains a challenge. In the current study, potato starch-pectin (PSP) composite films were fabricated and enriched with juniper berry essential oil (JBEO) to improve their physicochemical properties. The effects of incorporating different concentrations of JBEO (0.1%-1% v/v) on various properties of PSP-based films were evaluated, including surface color, transparency, barrier properties, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA and DTA), antioxidant activity, and antimicrobial effectiveness. Increasing the level of JBEO led to a significant decrease in the moisture content, film transparency, and mechanical attributes, while an increase in thickness, water permeability, and film elongation was observed. SEM analysis also revealed morphological properties such as some spherical, bubble-like configuration and cracks on the surface due to an increase in JBEO concentration. TGA and DTA revealed lower weight loss in the initial cycles due to the addition of JBEO, and the thermal stability of the films improved. The antioxidant assays revealed a concentration-dependent increase in the radical scavenging capacity of the films from 11.31% to 17.28% for DPPH and from 3.06% to 25.53% for ABTS. Moreover, significant antibacterial and antifungal activity of the bioactive films was observed against P. aeruginosa, S. aureus, and C. albicans. These findings suggest that JBEO enhances the functional properties of PSP films, making them suitable for active food packaging applications.

Characterization of Physicochemical Properties, Bioactivities, and Sensory Attributes of Sea Buckthorn-Fava Bean Composite Instant Powder: Spray-Drying Versus Freeze-Drying Coupled with Carriers

Foods and beverages with health benefits have become increasingly popular with consumers, and fruits and legumes are considered good sources of nutrients. In this study, sea buckthorn and fava bean were used as the main raw materials to prepare sea buckthorn-fava bean composite instant powder (S-FCP). Different drying methods (spray-drying (SD) and freeze-drying (FD)) combined with carriers (maltodextrin (MD) and inulin (INU)) were involved to investigate their effects on physicochemical properties, functional properties, and sensory attributes of instant powder. The results showed that FD better protected the color of the S-FCP and produced particles possessing more porous structures compared to SD; FD-INU (freeze-dried-inulin) had the shortest dissolution time and the largest solubility. In addition, FD-INU had the highest total phenolic and total flavonoid contents and the strongest antioxidant capacity, and FD-INU had better overall organoleptic properties and hypoglycemic potential. Therefore, FD and the use of INU as a carrier are more suitable for the production of the S-FCP. This work provides a promising approach for developing a high-valued instant powder beverage composed of sea-buckthorn/broad bean, which also contributes to the development of the functional food industry.

Insights on tiger nut (Cyperus Esculentus L.) oil-loaded microcapsules: characterization and oxidation stability analysis

In this paper, tiger nut oil-loaded microcapsules (TNOMs) were prepared by complexation soybean protein isolate (SPI) and maltodextrin (MD) as wall materials using the spray drying method with tiger nut oil (TNO) as the core material, and its physicochemical properties and stabilities were characterized and analyzed. Under the optimum conditions, the encapsulation efficiency (EE) of TNOMs could reach up to 91.23%. Of note, after 60 days of storage at 60 °C, the peroxide value (PV) of TNO was almost 21.8 times as much as that of TNO encapsulated. Furthermore, TNOMs had good thermal stability below 200 °C and are sufficient for the general food processing needs. By fitting Arrhenius oxidation kinetics model, it was predicted that the shelf life of the product stored at 25 °C was 352.48 d. Therefore, it is promised to be applied to the development of high oleic acid food in the future. This study offered a theoretical framework for utilization and broadening the range of applications of TNO in the food industry.

Improvement in the oxidative stability of microencapsulated linseed oil using carob protein hydrolysates and multilayer emulsions

The microencapsulation of linseed oil in multilayer emulsions stabilized by carob protein hydrolysates was evaluated in this study. Linseed oil was emulsified in both multilayer and single layer interfacial emulsions using either carob protein concentrate or carob protein hydrolysate. The protein hydrolysate was able to increase the encapsulation efficiency by up to 12 % compared to non-hydrolyzed concentrated protein. Larger particles containing the hydrolysates (mean diameter ∼3 µm) were observed; however, the size distribution and microstructure were similar for all samples, regardless of the use of protein concentrate or protein hydrolysate, in single or multilayer emulsion systems. Physical aspects of the particles, such as porosity and glass transition temperature (Tg), were also similar, showing low porosity (<7.5 %) and high Tg (>80 °C). The antioxidant capacity of the protein hydrolysates, combined with the protective effect provided by the multilayer systems, enhanced the oxidative stability of the microencapsulated oil during processing and storage. The use of both strategies seems to provide an improved alternative for the microencapsulation of linseed oil, resulting in particles with superior physicochemical and oxidative stability.

Preparation of Low-Fishy Microencapsulated DHA-Rich Algal Oil Powder Using Infant Rice Powder

Commercial DHA-rich algal oil has some issues, such as an unpleasant odor and susceptibility to oxidation. The main fishy odor compounds in commercial DHA-rich algal oil powder and DHA-rich algal oil microcapsules are hexanal and (E, E)-2,4-heptadienal. To address this issue, a microencapsulation process was designed for DHA-rich algal oil using infant rice powder (IRP), maltodextrin (MD), and whey protein concentrate (WPC) as wall materials, with sodium starch octenyl succinate (SSOS) and monoacylglycerol (MAC) as emulsifiers. The spray-drying method was used for microencapsulation. The experimental data showed that microcapsules with wall materials in a ratio of IRP/MD/WPC = 1:3:1 and an emulsifier content of 3.5% (SSOS and MAC) had the highest encapsulation efficiency (85.20 ± 6.03%) and the lowest aldehyde content (65.38 ± 3.23%). This microcapsule showed a good appearance and better oxidation stability compared with the crude oil, with a water content and average particle size of 1.69 ± 0.57% and 631.60 ± 23.19 nm, respectively. The results indicated that DHA-rich algal oil microcapsules prepared with infant rice powder had a lower fishy odor and better sensory acceptability compared to commercial DHA-rich algal oil powder.

Study on color and flavor changes of 4D printed white mushroom gel with microcapsules containing gelatin / β-cyclodextrin induced by microwave heating

The feasibility of microwave heating to induce color/flavor changes of 4D printed white mushroom gel containing curcumin or γ-dodecalactone (γ-DDL) microcapsules was studied. Using gelatin/ β-cyclodextrin as wall material and soy protein isolate as emulsifier, microcapsules containing curcumin or γ-DDL were prepared by spray drying method. The microcapsules containing curcumin were mixed into white mushroom powder at different mass ratios (0, 0.1, 1, 3, 5 %, w/w) as printing ink. With the increase of microcapsule content, the viscosity, storage modulus and loss modulus of printing ink increased, but the water distribution and recovery performance did not change significantly. With the extension of heating time, the brightness value (L*) and the redness value (a*) of the printed sample increased, and the yellowness value (b*) decreased. After adding 3 % (w/w) microcapsules containing γ-DDL, the content change of the target flavor substance in the printed sample during microwave treatment was determined based on Gaschromatography-mass spectrometry (GC-MS). The results showed that microwave treatment could promote the release of flavor substances, and the content was 272.37 μg/kg when heated for 3 min. This study provides a new idea for the development of 4D printed food with special color and target flavor based on microcapsule technology.

Enhanced antimicrobial activity against oral bacteria Actinomyces viscous by cinnamaldehyde emulsion microencapsulated with cyclodextrin glycosyltransferase-catalyzed products

Actinomyces viscous (A. viscous) is well documented as a major cariogenic bacterium in the oral cavity and needs to be inhibited and removed timely. Essential oils (EOs) are recognized as secure antibacterial agents for treating oral diseases, but their volatility and insolubility limit their application. In this study, cinnamaldehyde was screened as the optimum EO for inhibiting the A. viscous growth by a micro-agar dilution method and microencapsulated by cyclodextrin glycosyltransferase (CGTase)-catalyzed products. The antibacterial effects against A. viscous were investigated and compared with the free cinnamaldehyde. Antibacterial diameter, antibacterial efficiency and stability, and time-kill curve results revealed that the cinnamaldehyde emulsion had better antibacterial properties. 1 MIC of the cinnamaldehyde emulsion had an inhibitory zone of 9.92 nm, a 100 % inhibition rate when acting for 2 min or 5 min, and still maintained the same inhibitory effect for 2 years. The extracellular environment showed more pH decrease, conductivity increase, and protein leakage, suggesting damage to the cell membrane. Microstructure and flow cytometric analysis further revealed that the CGTase-catalyzed products induced more changes in the A. viscous membrane integrity. Based on the results, CGTase-catalyzed products can be used as a potential substance for encapsulating EOs for treating oral bacteria.

Hurdle technology using enzymes and essential oil to remove biofilm and increase the effectiveness of this process with the microencapsulation method

The formation of biofilm in different places and the failure to effectively remove it by the usual disinfection methods is due to its structure and the rich genetic resource available in it to deal with disinfectants. These impenetrable structures and diverse microbial genetics have caused biofilm pollution in different industries like the food industry, the medicine industry, the hospitals and the water distribution system, resulting in pathogenicity and reduction of industrial quality. An efficient way to deal with the resistant population of biofilm-forming microbes is the use of hurdle technology including enzymes and essential oils. Enzymes reduce the resistance of the biofilm structure due to degradation of its extracellular polymer matrix (EPS) by their abilities to break down the organic molecules, and then the essential oils weaken the cells by penetrating the lipid membrane of the cell and destroying its integrity; as a result, the biofilm will be destroyed. The advantage of this hurdle technology is the environmental friendly of both methods, which reduces concerns about the use of chemical disinfection methods, but on the other hand, due to the sensitivity of enzymes as biological agents also the expensiveness of this technique and the considerations of working with essential oils as volatile and unstable liquids should abandon the routine methods of applying this disinfectant to biofilm and go for the microencapsulation method, which as a protective system increases the effectiveness of enzymes and essential oils as antibiofilm agents.

Developmental Formulation Principles of Food Preservatives by Nanoencapsulation-Fundamentals, Application, and Challenges

The role of food additives is to preserve food by extending shelf life and limiting harmful microorganism proliferation. They prevent spoilage by enhancing the taste and safety of food by utilizing beneficial microorganisms and their antimicrobial metabolites. Current advances in food preservation and processing utilize green technology principles for green preservative formulation, enhancing nutrition and supplying essential micronutrients safely, while also improving quality, packaging, and food safety. Encapsulation is gaining attention for its potential to protect delicate materials from oxidative degradation and extend their shelf life, thereby ensuring optimal nutrient uptake. Nanoencapsulation of bioactive compounds has significantly improved the food, pharmaceutical, agriculture, and nutraceutical industries by protecting antioxidants, vitamins, minerals, and essential fatty acids by controlling release and ensuring delivery to specific sites in the human body. This emerging area is crucial for future industrial production, improving the sensory properties of foods like color, taste, and texture. Research on encapsulated bioactive compounds like bacteriocins, LAB, natamycin, polylysine, and bacteriophage is crucial for their potential antioxidant and antimicrobial activities in food applications and the food industry. This paper reviews nanomaterials used as food antimicrobial carriers, including nanoemulsions, nanoliposomes, nanoparticles, and nanofibers, to protect natural food antimicrobials from degradation and improve antimicrobial activity. This review discusses nanoencapsulation techniques for biopreservative agents like nisin, poly lysine, and natamycin, focusing on biologically-derived polymeric nanofibers, nanocarriers, nanoliposomes, and polymer-stabilized metallic nanoparticles. Nanomaterials, in general, improve the dispersibility, stability, and availability of bioactive substances, and this study discusses the controlled release of nanoencapsulated biopreservative agents.

Oral soluble shell prepared from OSA starch incorporated with tea polyphenols for the microencapsulation of Sichuan pepper oleoresin: Characterization, flavor stability, release mechanisms and its application in mooncake

The market share of Sichuan pepper oleoresin (SPO) in the flavor industry is increasing steadily; however, its high volatility, low water solubility, and poor stability continue to pose significant challenges to application. The microencapsulation prepared by emulsion embedding and spray drying is considered as an effective technique to solve the above problems. Sodium octenyl succinate starch (OSA starch) and tea polyphenols (TPs) were used to develop OSA-TPs complex as encapsulants for SPO to prepare orally soluble microcapsules. And the optimum doping of TPs was determined. SPO microcapsules have good properties with high encapsulation efficiency up to 88.13 ± 1.48% and high payload up to 41.58 ± 1.86% with low water content and high heat resistance. The binding mechanism of OSA starch with TPs and its regulation mechanism and effect on SPOs were further analyzed and clarified. The binding mechanism between OSA starch and TPs was clarified in further analyses. The OSA-TPs complexes enhanced the rehydration, release in food matrix and storage stability of SPO, and exhibited good sensory immediacy. Flavor-improved mooncakes were successfully developed, achieving the combination of mooncake flavor and SPO flavor. This study provided a valuable way to prepare flavoring microcapsules suitable for the catering industry, opened up the combined application of SPO and bakery ingredients, and was of great practical value and significance for improving the processing quality of flavor foods, driving the development of the SPO industry, and enhancing the national dietary experience.

Understanding emulsifier influence on complex coacervation: Essential oils encapsulation perspective

The objective of this research was to explore the viability of pea protein as a substitute for gelatin in the complex coacervation process, with a specific focus on understanding the impact of incorporating an emulsifier into this process. The study involved the preparation of samples with varying polymer mixing ratios (1:1, 1:2, and 2:1) and emulsifier content. As core substances, black pepper and juniper essential oils were utilized, dissolved beforehand in grape seed oil or soybean oil, to minimize the loss of volatile compounds. In total, 24 distinct samples were created, subjected to freeze-drying to produce powder, and then assessed for their physicochemical properties. Results revealed the significant impact of emulsifier addition on microcapsule parameters. Powders lacking emulsifiers exhibited higher water solubility (57.10%-81.41%) compared to those with emulsifiers (24.64%-40.13%). Moreover, the emulsifier significantly decreased thermal stability (e.g., without emulsifier, Ton = 137.21°C; with emulsifier, Ton = 41.55°C) and adversely impacted encapsulation efficiency (highest efficiency achieved: 67%; with emulsifier: 21%).

Design of an antioxidant powder additive based on carvacrol encapsulated into a multilayer chitosan-alginate-maltodextrin emulsion

Carvacrol has demonstrated antioxidant activity; however, its high volatility and low water solubility limit its direct application in food matrices. Then, an effective encapsulation system is required to protect it. This study aimed to design and characterize a carvacrol-based additive encapsulated in a spray-dried multilayer emulsion based on chitosan/sodium alginate/maltodextrin. Spray-drying temperature of 120 °C and 3 %(w/w) maltodextrin content maximized both encapsulation efficiency (~97 %) and loading capacity (~53 %). The powder's antioxidant properties were evaluated in two food simulant media: water (SiW) and water-ethanol (SiD). The highest antioxidant activity was observed in SiW for both ABTS•+ (8.2 ± 0.3mgEAG/g) and FRAP (4.1 ± 0.2mgEAG/g) methods because of the reduced release of carvacrol in SiD vs. SiW, as supported by micro- and macrostructural observations by SAXS and microscopy, respectively. An increase from 143 to 157 °C attributable to carvacrol protection and Tg = 44.4 °C (> ambient) were obtained by TGA and DSC, respectively. FT-IR confirmed intermolecular interactions (e.g. -COO- and -NH3+) as well as H-bonding formation. High water solubility (81 ± 3 %), low hygroscopicity (8.8 ± 0.2 %(w/w), poor flowability (CI:45 ± 4), and high cohesiveness (HR:1.8 ± 0.1) between particles were achieved, leading to a powdered antioxidant additive with high potential for applications which required avoiding/reducing oxidation on hydrophilic and hydrophobic food products.

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.

Multilayer microparticles for programmed sequential release of phenolic compounds from Eugenia stipitata: Stability and bioavailability

A co-delivery system based on multilayer microparticles was developed and characterized for the sequential release of phenolic compounds (PCs) using different encapsulation processes (spray drying: SD and drying-chilling spray: SDC) and wall materials to improve the stability and bioavailability of PCs. Samples were characterized in terms of process yield (PY%), phenolic retention efficiency (PRE%), chemical structure and crystallinity (NMR, FTIR, DXR), thermal stability (DSC and FT-IR), anti-radical capacity (ORAC and ABTS) and in vitro digestion. PRE% of samples by SD were higher (p < 0.05) than SDC due to the formation of PCs from CRF (cará-roxo flour). NMR, FTIR, DXR confirmed the presence of key components and interactions for the formation of the advanced co-delivery system. The SDC particles showed crystalline regions by XRD and were stable at ∼47 °C. All samples showed good release of PC in the intestinal phase, and antiradical capacity that reached 23.66 µmol TE g-1.

Preparation and sustained-release of chitosan-alginate bilayer microcapsules containing aromatic compounds with different functional groups

This study investigated the release of aromatic compounds with distinct functional groups within bilayer microcapsules. Bilayer microcapsules of four distinctive core materials (benzyl alcohol, eugenol, cinnamaldehyde, and benzoic acid) were synthesized via freeze-drying. Chitosan (CS) and sodium alginate (ALG) were used as wall materials. CS concentration, using orthogonal experiments with the loading ratio as a metric. Under optimal conditions, three other types of microcapsules (cinnamic aldehyde, benzoic acid, and benzyl alcohol) were obtained. The four types of microcapsules were characterized using Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscope (TEM), and thermogravimetric analysis (TGA), and their sustained release characteristics were evaluated. The optimal conditions were: CS dosage, 1.2 %; CS-to-eugenol mass ratio, 1:2; and CS-to-ALG mass ratio, 1:1. By comparing the IR spectra of the four types of microcapsules, wall material, and core material, the core materials were revealed to be encapsulated within the wall material. SEM results revealed that the granular protuberances on the surface of the microcapsules were closely aligned and persistent when magnified 2000×. The TEM results indicated that all four microcapsules had a spherical and bilayer structure. The thermal stability and sustained release results showed that the four microcapsules were more resilient and less volatile than the four core materials. The release conformed to first-order kinetics, and the release ratios of the four microcapsules were as follows: benzyl alcohol microcapsules ˃ eugenol microcapsules ˃ cinnamaldehyde microcapsules ˃ benzoic acid microcapsules. The prepared bilayer microcapsules encapsulated four different core materials with good sustained release properties.

Microencapsulation of fish oil by spray drying, spray freeze-drying, freeze-drying, and microwave freeze-drying: Microcapsule characterization and storage stability

The objective of this paper was to evaluate the effect of spray drying (SD), spray freeze-drying (SFD), freeze-drying (FD), and microwave freeze-drying (MFD) on the characteristics of fish oil (FO) microcapsules. The physicochemical properties, morphology, fatty acid composition, and stability of the microcapsules were analyzed. The encapsulation efficiencies of microcapsules dried by SD, SFD, FD, and MFD were 86.98%, 77.79%, 63.29%, and 57.89%, respectively. SD microcapsules exhibited superior properties in terms of effective loading capacity, color, and flowability. Conversely, SFD microcapsules demonstrated improved solubility. Microencapsulation positively affected the thermal stability of FO, but the content of unsaturated fatty acids decreased. The findings from the storage experiment indicated that the oxidative stability of SD fish oil microcapsules was marginally lower compared to microcapsules produced through three alternative drying techniques, all of which were based on the FD concept. The comparison of various drying methods and their effects on the quality of FO microcapsules offers valuable insights that can serve as a foundation for the industrial production of high-quality microcapsules.

Advances in encapsulation systems of Antarctic krill oil: From extraction to encapsulation, and future direction

Antarctic krill oil (AKO) is highly sought after by consumers and the food industry due to its richness in a variety of nutrients and physiological activities. However, current extraction methods are not sufficient to better extract AKO and its nutrients, and AKO is susceptible to lipid oxidation during processing and storage, leading to nutrient loss and the formation of off-flavors and toxic compounds. The development of various extraction methods and encapsulation systems for AKO to improve oil yield, nutritional value, antioxidant capacity, and bioavailability has become a research hotspot. This review summarizes the research progress of AKO from extraction to encapsulation system construction. The AKO extraction mechanism, technical parameters, oil yield and composition of solvent extraction, aqueous enzymatic extraction, supercritical/subcritical extraction, and three-liquid-phase salting-out extraction system are described in detail. The principles, choice of emulsifier/wall materials, preparation methods, advantages and disadvantages of four common encapsulation systems for AKO, namely micro/nanoemulsions, microcapsules, liposomes and nanostructured lipid carriers, are summarized. These four encapsulation systems are characterized by high encapsulation efficiency, low production cost, high bioavailability and high antioxidant capacity. Depending on the unique advantages and conditions of different encapsulation methods, as well as consumer demand for health and nutrition, different products can be developed. However, existing AKO encapsulation systems lack relevant studies on digestive absorption and targeted release, and the single product category of commercially available products limits consumer choice. In conjunction with clinical studies of AKO encapsulation systems, the development of encapsulation systems for special populations should be a future research direction.

Advances in protein-based microcapsules and their applications: A review

Due to their excellent emulsification, biocompatibility, and biological activity, proteins are widely used as microcapsule wall materials for encapsulating drugs, natural bioactive substances, essential oils, probiotics, etc. In this review, we summarize the protein-based microcapsules, discussing the types of proteins utilized in microcapsule wall materials, the preparation process, and the main factors that influence their properties. Additionally, we conclude with examples of the vital role of protein-based microcapsules in advancing the food industry from primary processing to deep processing and their potential applications in the biomedical, chemical, and textile industries. However, the low stability and controllability of protein wall materials lead to degraded performance and quality of microcapsules. Protein complexes with polysaccharides or modifications to proteins are often used to improve the thermal instability, pH sensitivity, encapsulation efficiency and antioxidant capacity of microcapsules. In addition, factors such as wall material composition, wall material ratio, the ratio of core to wall material, pH, and preparation method all play critical roles in the preparation and performance of microcapsules. The application area and scope of protein-based microcapsules can be further expanded by optimizing the preparation process and studying the microcapsule release mechanism and control strategy.

Preparation and characterization of active films based on oregano essential oil microcapsules/soybean protein isolate/sodium carboxymethyl cellulose

This study aimed to prepare oregano essential oil microcapsules (EOMs) by the active coalescence method using gelatin and sodium alginate as wall materials and oregano essential oil (OEO) as the core material. EOMs were added to the soybean protein isolate (SPI)/sodium carboxymethyl cellulose (CMC) matrix to prepare SPI-CMC-EOM active films, and the physical and chemical features of the active films and EOMs were characterized. The results showed that the microencapsulated OEO could protect its active ingredients. Scanning electron microscopy results showed that EOMs were highly compatible with the film matrix. The solubility of active films decreased upon adding EOMs, and their ultraviolet resistance and thermal stability also improved. When the added amount of EOMs was 5 %, the active films had the best mechanical properties and the lowest water vapor permeability. The active films prepared under this condition had excellent comprehensive performance. Also, adding EOMs considerably enhanced the antioxidant of the active films and endowed them with antibacterial properties. The application of the SPI-CMC-EOM films to A. bisporus effectively delayed senescence and maintained the freshness of the postharvest A. bisporus. This study provided a theoretical foundation for the incorporation of EOMs into active films based on biological materials.

Preparation and characterization of starch/PBAT film containing hydroxypropyl-β-cyclodextrin/ethyl lauroyl arginate/cinnamon essential oil microcapsules and its application in the preservation of strawberry

Cinnamon essential oil (CEO) was emulsified by hydroxypropyl-β-cyclodextrin/ ethyl lauroyl arginate (HPCD/LAE) complex to make nanoemulsions, which were then incorporated into maltodextrin (MD) to prepare HPCD/LAE/CEO/MD microcapsules by spray drying. The starch/polybutylene adipate terephthalate (starch/PBAT, SP) based extrusion-blowing films containing above microcapsules were developed and used as packaging materials for strawberry preservation. The morphology, encapsulation efficiency, thermal and antibacterial properties of microcapsules with different formulations were investigated. The effects of microcapsules on the physicochemical and antimicrobial properties of SP films were evaluated. When the formula was 4 % HPCD/LAE-3% CEO-10% MD (HL-3C-MD), the microcapsule had the smallest particle size (3.3 μm), the highest encapsulation efficiency (84.51 %) of CEO and the best antibacterial effect. The mechanical and antimicrobial properties of the SP film were enhanced while the water vapor transmittance and oxygen permeability decreased with the incorporation of HL-3C-MD microcapsules. The films effectively reduced the weight loss rate (49.03 %), decay rate (40.59 %) and the total number of colonies (2.474 log CFU/g) and molds (2.936 log CFU/g), thus extending the shelf life of strawberries. This study revealed that the developed SP films containing HPCD/LAE/CEO microcapsules had potential applications in degradable bioactive food packaging materials.

Exploration of optimal preparation strategy of Chenpi (pericarps of Citrus reticulata Blanco) flavouring essence with great application potential in sugar and salt-reduced foods

To obtain flavouring essence with application potential in sugar and salt-reduced foods, the optimal strategy for extraction and microencapsulation of essential oil (EO) from Chenpi was investigated. UPLC-QTOF-MS/MS and liquid-liquid-extraction-GC-MS confirmed the selectivity for volatiles ranked in hydrodistillation > supercritical fluid extraction > solvent extraction. The aroma characteristic of Chenpi EO was distinguished by 33 key volatiles (screened out via headspace-SPME-GC-MS) and quantitative descriptive analysis. EO extracted by supercritical fluid extraction was preferred for preserving the original aroma of Chenpi and displaying more fruity, honey and floral. Chenpi flavouring essence with superior encapsulation efficiency, particle size, water dispersibility, and thermostability was obtained through optimally microencapsulating EO with gum arabic and maltodextrin (1:1) by high-pressure homogenization coupled with spray drying. Chenpi flavouring essence was able to reduce the usage of sugar and salt by 20 % via enhancing flavour perception of sweetness and saltiness. This study first developed a flavouring essence promisingly effective in both sugar and salt-reduced foods.

Microencapsulation of green coffee oil by complex coacervation of soy protein isolate, sodium casinate and polysaccharides: Physicochemical properties, structural characterisation, and oxidation stability

This study developed a combination method between protein-polysaccharide complex coacervation and freezing drying for the preparation of green coffee oil (GCO) encapsulated powders. Different combinations of soy protein isolate, sodium caseinate, sodium carboxymethylcellulose, and sodium alginate were utilised as wall materials. The occurrence of complexation between the biopolymers were compared to the final emulsion of the individual protein and confirmed by fourier transform infrared spectrometry and X-ray diffraction. The mean diameter and estimated PDI of GCO microcapsules were 72.57-295.00 μm and 1.47-2.02, respectively. Furthermore, the encapsulation efficiency of GCO microcapsules was between 61.47 and 90.01 %. Finally, oxidation kinetics models of GCO and its microcapsules demonstrated that the zero-order model of GCO microcapsules was found to have a higher fit, which could better reflect the quality changes of GCO microcapsules during storage. Different combinations of proteins and polysaccharides exhibited effective oxidative stability against single proteins because of polysaccharide addition. This research revealed that soy protein isolate, sodium caseinate combined with polysaccharides can be used as a promising microencapsulating agent for microencapsulation of GCO, especially with sodium carboxymethylcellulose and sodium alginate, and provided useful information for the potential use of GCO in the development of powder food.

Investigating the effect of wall material and pressure homogenisation on encapsulation parameters and thermal stability in chia seed oil microcapsules

AIM

To evaluate the effect of different wall material (WM) matrices followed by homogenisation to encapsulate chia seed oil (CSO) using freeze drying technology.

METHODS

CSO was encapsulated using three ratios (100/0, 50/50, and 100/0) of two WM matrices: MTS/WPC (modified tapioca starch-whey protein concentrate) and MD/WPC (maltodextrin-whey protein concentrate). The evaluation included encapsulation efficiency (EE), oxidative stability, and α-linolenic acid (ALA) retention. Homogenised microcapsules (-H) were then assessed for storage and thermal stability, along with cumulative oil release.

RESULTS

The MD-WPC-H 50/50 microcapsules had superior EE (97.32%), higher ALA retention (60.2%), storage stability (up to 30 days), higher thermal stability (up to 700 °C), and desirable oil release in simulated condition.

CONCLUSION

Selecting suitable WM and homogenisation is key for improving EE, storage, thermal stability, and targeted release. The CSO microcapsule can serve as a functional ingredient to improve the quality of diverse food products.

Microencapsulation of bioactive compound extracts using maltodextrin and gum arabic by spray and freeze-drying techniques

Microencapsulation techniques establish a protective barrier around a sensitive compound, reducing vulnerability to external influences and offering controlled release. This work evaluates microencapsulation of Brazilian seed known as pink pepper (Schinus terebinthifolius) extract incorporated with green propolis extract, (main propolis font from the South America native plant Baccharis dracunculifolia DC) to enhancement antioxidant activity through synergic interaction, comparing to the extracts individually. Four treatments were produced using maltodextrin and combined with gum arabic as encapsulating agent, employing two different microencapsulation technique applied (spray drying and freeze drying) to assess their impact on physicochemical properties. The incorporation of gum arabic into matrix yielded higher encapsulation efficiency values, exhibiting significant differences for both encapsulation techniques. Combining the two encapsulation agents afforded greater protection of the bioactive compounds, resulting in an increase of approximately 31 % in the inhibition of the DPPH● radical. In controlled release analysis, maltodextrin exhibits the best protective effect on total phenolic compounds during intestinal release, whereas combining maltodextrin and gum arabic enhanced protection during gastric phase. Microcapsules may contribute to the protection of important bioactive compound, possessing a wide range of applications such as flavors encapsulation in food industry, lipids, antioxidants and pharmaceutical industry for controlled drug release.

Alginate-based edible coating with oregano essential oil/β-cyclodextrin inclusion complex for chicken breast preservation

A sodium alginate (SA) edible coating containing oregano essential oil (OEO)/β-cyclodextrin (β-CD) inclusion complexes (SA/OEO-MP coating) was developed to extend the shelf life of fresh chicken breast during refrigeration storage. First, OEO was inserted into the hydrophobic interior of β-CD to form an inclusion complex (OEO-MP) that maintained its excellent antioxidant and antibacterial activities. The formed OEO-MP was characterized using fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). In addition, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) results demonstrated that β-CD could improve the thermal stability of OEO. The encapsulation efficiency reached 71.6 %, and OEO was released continuously from the OEO-MP. The lipid oxidation, total viable count (TVC) and sensory properties of chicken breasts were regularly monitored when OEO-MP was incorporated into the SA coating for chicken breast preservation. Compared with the uncoated group, the SA/OEO-MP-coated groups showed significantly reduced increases in pH, thiobarbituric acid reactive substances (TBARS), total volatile base nitrogen (TVB-N), and TVC, especially in the SA/OEO-MP1 group. In summary, the SA/OEO-MP coating could preserve the chicken breast by reducing lipid oxidation and inhibiting the proliferation of microorganisms. It would be developed as a prospective edible packaging for chicken preservation.

Research progress of starch as microencapsulated wall material

Starch is non-toxic, low cost, and possesses good biocompatibility and biodegradability. As a natural polymer material, starch is an ideal choice for microcapsule wall materials. Starch-based microcapsules have a wide range of applications and application prospects in fields such as food, pharmaceuticals, cosmetics, and others. This paper firstly reviews the commonly used wall materials and preparation methods of starch-based microcapsules. Then the effect of starch wall materials on microcapsule properties is introduced in detail. It is expected to provide researchers with design inspiration and ideas for the development of starch-based microcapsules. Next the applications of starch-based microcapsules in various fields are presented. Finally, the future trends of starch-based microcapsules are discussed. Molecular simulation, green chemistry, and solutions to the main problems faced by resistant starch microcapsules may be the future research trends of starch-based microcapsules.

Preparation, characterization and release kinetics of a multilayer encapsulated Perilla frutescens L. essential oil hydrogel bead

Encapsulation has been widely used as the protection of essential oils, which gives the possibility of their implementation as food preservatives. In this study, Perilla frutescens L. essential oil (PLEO) microcapsule powders were prepared firstly by spray drying method using octenyl succinic anhydride starch (OSAs) as wall material, and then they were further encapsulated by sodium alginate and chitosan via polyelectrolyte complex coacervates method. The best results were obtained by using 4 % of OSAs-PLEO microcapsule powders, 2 % of sodium alginate and 1.5 % of chitosan producing PLEO hydrogel beads with encapsulation efficiency of 61.29 % and loading degree of 41.11 %. Morphology observation showed PLEO hydrogel beads was a millimeter scale spherical particle. FTIR assay confirmed the physical embedding of OSAs on PLEO and the formation of complex coacervates between sodium alginate and chitosan. TG and DSC assay showed the chitosan/alginate/OSAs complex coacervates as wall materials substantially improved the thermal stability of PLEO. Besides, PLEO hydrogel beads had a better stability in aqueous and acidic food formulations, which achieved a complete and prolonged release of PLEO. The Peppas-Sahlin model was the best approach for PLEO release profile, and release phenomenon was mainly governed by Fickian diffusion.

Plant-inspired adhesive and injectable natural hydrogels: in vitro and in vivo studies

The development of alternative therapeutic treatments based on the use of medicinal and aromatic plants, such as Juniper communis L., has aroused interest in the medical field to find new alternatives to conventional therapeutic treatments, which have shown problems related to bacterial resistance, high costs, or sustainability in their production. The present work describes the use of hydrogels based on sodium alginate and carboxymethyl cellulose, with combinations of juniperus leaves and berry extracts, in order to characterize their chemical characteristics, antibacterial activity, tissue adhesion test, cytotoxicity in the L929 cell line, and their effects on an in vivo model in mice to maximize the use of these materials in the healthcare field. Overall, an adequate antibacterial potential against S. aureus, E. coli and P. vulgaris was obtained with doses above 100 mg.mL-1 of hydrogels. Likewise, low cytotoxicity in hydrogels combined with extracts has been identified according to the IC50 value at 17.32 µg.mL-1, compared to the higher cytotoxic activity expressed by the use of control hydrogels with a value at 11.05 µg.mL-1. Moreover, in general, the observed adhesion was high to different tissues, showing its adequate capacity to be used in different tissue typologies. Furthermore, the invivo results have not shown erythema, edema, or other complications related to the use of the proposed hydrogels. These results suggest the feasibility of using these hydrogels in biomedical applications given the observed safety.

Advances in Controllable Release Essential Oil Microcapsules and Their Promising Applications

Essential oils (EOs) have emerged as natural and popular ingredients used in the preparation of safe and sustainable products because of their unique characteristics, such as antibacterial and antioxidant activity. However, due to their high volatility, poorly solubility in water, and susceptibility to degradation and oxidation, the application of EOs is greatly limited. One of the promising strategies for overcoming these restrictions is encapsulation, which involves in the entrapment of EOs inside biocompatible materials to utilize their controllable release and good bioavailability. In this review, the microencapsulation of the controllable release EOs and their applications are investigated. The focus is on the antimicrobial mechanism of various EOs on different bacteria and fungi, release mechanism of microencapsulated EOs, and preparation research progress of the controllable EOs microcapsules. In addition, their applications are introduced in relation to the food, textiles, agriculture, and medical fields.

Optimized Peppermint Essential Oil Microcapsules Loaded into Gelatin-Based Cryogels with Enhanced Antimicrobial Activity

In this study, chitosan (Chi) was used to microencapsulate peppermint essential oil (PEO). A novel gelatin-based cryogel loaded with PEO microcapsules was further developed and characterized for potential applications. Four different cryogel systems were designed, and the morphological, molecular, physical and antibacterial properties were investigated. Additionally, the antimicrobial properties of PEO, alone and microcapsulated, incorporated into the cryogel network were evaluated. The observed gel structure of cryogels exhibited a highly porous morphology in the microcapsules. The highest values of the equilibrium swelling ratio were acquired for the GelCryo-ChiCap and GelCryo-PEO@ChiCap samples. The contact angle GelCryo-PEO@ChiCap sample was lower than the control (GelCryo) due to the water repelling of the essential oil. It has been found that the incorporation of encapsulated PEO into the cryogels would be more advantageous compared to its direct addition. Moreover, GelCryo-PEO@ChiCap cryogels showed the strongest antibacterial activities, especially against Staphylococcus aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria). The system that was developed showed promising results, indicating an improved antibacterial efficacy and enhanced structural properties due to the presence of microcapsules. These findings suggest that the system may be an appropriate candidate for various applications, including, but not limited to, drug release, tissue engineering, and food packaging. Finally, this system demonstrates a strategy to stabilize the releasing of the volatile compounds for creating successful results.

Comparison of Alginate Mixtures as Wall Materials of Schizochytrium Oil Microcapsules Formed by Coaxial Electrospray

This work evaluated maltodextrin/alginate and β-glucan/alginate mixtures in the food industry as wall materials for the microencapsulation of Schizochytrium sp. oil, an important source of the omega-3 fatty acid DHA (docosahexaenoic acid). Results showed that both mixtures display a shear-thinning behavior, although the viscosity is higher in β-glucan/alginate mixtures than in maltodextrin/alginate. Scanning electron microscopy was used to assess the morphology of the microcapsules, which appeared more homogeneous for maltodextrin/alginate. In addition, oil-encapsulation efficiency was higher in maltodextrin/alginate mixtures (90%) than in β-glucan/alginate mixtures (80%). Finally, evaluating the microcapsules' stability by FTIR when exposed to high temperature (80 °C) showed that maltodextrin/alginate microcapsules were not degraded contrary to the β-glucan/alginate microcapsules. Thus, although high oil-encapsulation efficiency was obtained with both mixtures, the microcapsules' morphology and prolonged stability suggest that maltodextrin/alginate is a suitable wall material for microencapsulation of Schizochytrium sp. oil.

Combination of α-lactalbumin and gum Arabic for microencapsulation of L-menthol: The effects on flavor release during storage and rehydration

L-menthol-containing food products generally show the flavor loss during storage due to their high volatility. The hydrophobicity of L-menthol also causes the inadequate flavor release during rehydration. In this study, the stability of L-menthol was enhanced by microencapsulation and the effect of different powder drying techniques was also investigated. The highest efficiency (76.58-78.66 %) and loading content (18.58-28.35 mg/g) of encapsulations were obtained by using a mass ratio of 2:1(α-LA: GA). Then they were dried by non-thermal spray freeze drying (SFD) technique compared to spray drying (SD) and freeze-drying (FD) process. The SFD particles were shown to be spherical and porous with the highest porosity (86.82 %). α-LA/GA based microparticles with spherical shapes were demonstrated to largely enhance flavor retention during high humidity storage. In addition, the porous structures of SFD powders could cause rapid rehydration in liquid models, and the release behaviors of loaded L-menthol followed the Fickian diffusion. Consequently, the SFD technique shows great potential to produce microparticles by regulating the release behaviors of L-menthol during storage and rehydration.

Microencapsulation as a Route for Obtaining Encapsulated Flavors and Fragrances

Microencapsulation methods for active substances, such as fragrance compounds and aromas, have long been of interest to researchers. Fragrance compositions and aromas are added to cosmetics, household, and food products. This is often because the choice of a particular product is dictated by its fragrance. Fragrance compositions and aromas are, therefore, a very important part of the composition of these items. During production, when a fragrance composition or aroma is introduced into a system, unfavorable conditions often exist. High temperatures and strong mixing have a detrimental effect on some fragrance compounds. The environments of selected products, such as high- or low-pH surfactants, all affect the fragrance, often destructively. The simple storage of fragrances where they are exposed to light, oxygen, or heat also has an adverse effect. The solution to most of these problems may be the encapsulation process, namely surrounding small fragrance droplets with an inert coating that protects them from the external environment, whether during storage, transport or application, until they are in the right conditions to release the fragrance. The aim of this article was to present the possible, available and most commonly used methods for obtaining encapsulated fragrances and aromas, which can then be used in various industries. In addition, the advantages and disadvantages of each method were pointed out, so that the selection of the appropriate technology for the production of encapsulated fragrances and aromas will be simpler.