Microencapsulation by spray drying of lemon essential oil: Evaluation of mixtures of mesquite gum–nopal mucilage as new wall materials

Encapsulation of sunflower and flaxseed oils using Opuntia (Cactaceae) mucilage as a core-shell material through coacervation methods: A study on formulation, characterization, and in vitro digestion

Sunflower oil (SFO) and Flaxseed oil (FSO) were microencapsulated using simple and complex coacervation techniques with Opuntia (Cactaceae) mucilage (Mu) and with a combination of Mu with chitosan (Chit). The encapsulation efficiency (EE) of SFO and FSO in emulsions using Mu/Chit shells was 96.7% and 97.4%, respectively. Morphological studies indicated successful entrapment of oils in core shells with particle sizes ranging from 1396 ± 42.4 to 399.8 ± 42.3 nm. The thermogravimetric analyses demonstrated enhanced core protection with thermal stability noted for microcapsules regardless of encapsulation method. The stability of the microcapsules, during in vitro digestion was studied. The obtained results revealed that the microcapsules are intact in oral conditions and have a slow release of oil over stomach digestion and rapid release in the small intestine. The results showed that Mu and Mu/Chit coacervates can be used as effective carrier systems to encapsulate sensitive ingredients and functional oils.

Unveiling the mechanism of essential oil action against skin pathogens: from ancient wisdom to modern science

Essential oils are among the most well-known phyto-compounds, and since ancient times, they have been utilized in medicine. Over 100 essential oils have been identified and utilized as therapies for various skin infections and related ailments. While numerous commercial medicines are available in different dosage forms to treat skin diseases, the persisting issues include their side effects, toxicity, and low efficacy. As a result, researchers are seeking novel classes of compounds as substitutes for synthetic drugs, aiming for minimal side effects, no toxicity, and high efficacy. Essential oils have shown promising antimicrobial activity against skin-associated pathogens. This review presents essential knowledge and scientific information regarding essential oil's antimicrobial capabilities against microorganisms that cause skin infections. Essential oils mechanisms against different pathogens have also been explored. Many essential oils exhibit promising activity against various microbes, which has been qualitatively assessed using the agar disc diffusion experiment, followed by determining the minimum inhibitory concentration for quantitative evaluation. It has been observed that Staphylococcus aureus and Candida albicans have been extensively researched in the context of skin-related infections and their antimicrobial activity, including established modes of action. In contrast, other skin pathogens such as Staphylococcus epidermidis, Streptococcus pyogens, Propionibacterium acnes, and Malassezia furfur have received less attention or neglected. This review report provides an updated understanding of the mechanisms of action of various essential oils with antimicrobial properties. This review explores the anti-infectious activity and mode of action of essential against distinct skin pathogens. Such knowledge can be valuable in treating skin infections and related ailments.

Aloe Vera and Nopal mucilage on the reduction of agglomeration during spray drying and storage of blackberry and raspberry extracts

The objective of this investigation was to evaluate the influence of two carrier agents, Nopal and Aloe Vera mucilage on the physicochemical properties and stability of blackberry and raspberry powders obtained by spray drying. A pilot scale spray dryer with a feed flow of 20 L/h and an atomization speed of 28,000 rpm was used. The inlet and outlet air temperatures were from 180 to 80 °C, respectively. Yield, moisture content, water activity, hygroscopicity index, solubility time, volumetric density, stability diagrams, micrographs, and particle temperature were evaluated. The highest yields for blackberry extract were 75% with a concentration of 2.5% (w/v) Nopal mucilage, while raspberry extract yielded 65% with a concentration of 5% (w/v) Nopal mucilage. The increase in the concentration of the carrier agent presented an increase in the values of humidity, water activity, volumetric density, and solubility when Nopal mucilage was used as a carrier agent in both blackberry and raspberry extracts. Furthermore, when Aloe Vera mucilage was used as a carrier agent, these same values decreased with increasing concentration. The storage conditions of the powders obtained should be stored at temperatures below 20°C and water activities below 0.4. In addition, the stability diagrams show the particle conditions that should not be exceeded during spray drying.

Chitosan microparticles loaded with essential oils inhibit duo-biofilms of Candida albicans and Streptococcus mutans

OBJECTIVE

Oral candidiasis is a common fungal infection that affects the oral mucosa, and happens when Candida albicans interacts with bacteria in the oral microbiota, such as Streptococcus mutans, causing severe early childhood caries. C. albicans and S. mutans mixed biofilms are challenging to treat with conventional antimicrobial therapies, thus, new anti-infective drugs are required. This study aimed to test a drug delivery system based on chitosan microparticles loaded with geranium and lemongrass essential oils to inhibit C. albicans and S. mutans mixed biofilms.

METHODOLOGY

Chitosan microparticles loaded with essential oils (CM-EOs) were obtained by spray-drying. Susceptibility of planktonic were performed according CLSI at 4 to 2,048 µg/mL. Mixed biofilms were incubated at 37ºC for 48 h and exposed to CM-EOs at 256 to 4,096 µg/mL. The antimicrobial effect was evaluated using the MTT assay, with biofilm architectural changes analyzed by scanning electron microscopy. RAW 264.7 cell was used to evaluate compound cytotoxicity.

RESULTS

CM-EOs had better planktonic activity against C. albicans than S. mutans. All samples reduced the metabolic activity of mixed C. albicans and S. mutans biofilms, with encapsulated oils showing better activity than raw chitosan or oils. The microparticles reduced the biofilm on the slides. The essential oils showed cytotoxic effects against RAW 264.7 cells, but encapsulation into chitosan microparticles decreased their toxicity.

CONCLUSION

This study demonstrates that chitosan loaded with essential oils may provide an alternative method for treating diseases caused by C. albicans and S. mutans mixed biofilm, such as dental caries.

Influence of spray drying parameters on the physicochemical characteristics of microencapsulated pomelo (Citrus grandis (L.) Osbeck) essential oil

This study aimed to evaluate the encapsulation of pomelo (Citrus grandis (L.) Osbeck) essential oils using the spray drying technique. The parameters of the process include concentration of maltodextrin (20-35% by wt%/wt%), concentration of essential oil (1-2.5% by wt%/wt%), inlet temperature of spray drying (120-180 °C), and feed flow rates (120-240 mL/h) were soundly examined. The utilization of suitable parameters as the concentration of maltodextrin at 30% (by wt%/wt%), the concentration of essential oil at 1.5% (by wt%/wt%), the inlet temperature of 140 °C, and feed flow rate of 120 mL/h showed the highest drying yields (90.05%), microencapsulation yield (75.59%), and microencapsulation efficiency (89.44%). TGA and DSC results verified higher stability of Citrus grandis essential oil after encapsulation. The encapsulation of pomelo essential oils maintained most of the major components in comparison with the non-encapsulated essential oils without any significant changing in powder-obtained quality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01161-5.

Targeted delivery and controlled released of essential oils using nanoencapsulation: A review

Essential oils (EOs) contain a complex mixture of volatile and non-volatile molecules with diverse biological activities, including flavoring, antioxidant, antimicrobial, and nutraceutical properties. As a result, EOs have numerous potential applications in the agriculture, food, and pharmaceutical industries. However, their hydrophobicity, chemical instability, and volatility pose a challenge for many of their applications. These challenges can often be overcome by encapsulation EOs in colloidal delivery systems. Over the last decade or so, nanoencapsulation and microencapsulation technologies have been widely explored for their potential to improve the handling, dispersibility, and stability of hydrophobic substances, as well as to control their release profiles (e.g., targeted, triggered, sustained, or burst release). These technologies include emulsification, coacervation, precipitation, spray-drying, spray-cooling, freeze-drying, fluidized bed coating, and extrusion. This article reviews some of the most important developments in EOs encapsulation, the physicochemical mechanisms underlying the behavior of encapsulated EOs, current challenges, and potential applications in the food and biomedical sciences. This review has found that nanoencapsulation has countless of potential advantages for the utilization of EOs in the food industry and can improve their water-dispersibility, food matrix compatibility, chemical stability, volatility, and bioactivity.

The assessment of microencapsulated Lactobacillus plantarum survivability in rose petal jam and the changes in physicochemical, textural and sensorial characteristics of the product during storage

The present study aimed to develop a probiotic rose petal jam containing microencapsulated L. plantarum. The attributes of L. plantarum microcapsules and bacteria viability in simulated gastrointestinal conditions and jam were assessed. In addition, L. plantarum effects on physicochemical, textural and sensorial properties of jam were studied. The microencapsulation yield, diameter, and zeta potential value of the microcapsules ranged from 90.23 to 92.75%, 14.80–35.02 µm, and − 16.83 to − 14.71 mV, respectively. The microencapsulation process significantly increases the survival of L. plantarum in simulated gastrointestinal tract and jam. In jam samples containing L. plantarum microencapsulated with 2% sodium alginate and 3.5% or 5% Arabic gum and stored for 90 days, the bacterial count was higher than the acceptable level (10⁶ CFU/g). While there was no significant difference (P > 0.05) between physicochemical characteristics of non-probiotic and probiotic jams, taste and overall acceptance scores of microencapsulated probiotic jams were higher. The microencapsulation of L. plantarum in sodium alginate (2%) and Arabic gum (5%) and its inoculation into rose petal jam could yield a new probiotic product with increased health benefits.

Polysaccharides as wall materials in spray-dried microencapsulation of bioactive compounds: Physicochemical properties and characterization

Natural bioactive compounds (BCs) are types of chemicals found in plants and certain foods that promote good health, however they are sensitive to processing and environmental conditions. Microencapsulation by spray drying is a widely used and cost-effective approach to create a coating layer to surround and protect BCs and control their release, enabling the production of high functional products/ingredients with extended shelf life. In this process, wall materials determine protection efficiency, and physical properties, bioavailability, and storage stability of microencapsulated products. Therefore, an understanding of physicochemical properties of wall materials is essential for the successful and effective spray-dried microencapsulation process. Typically, polysaccharide-based wall materials are generated from more sustainable sources and have a wider range of physicochemical properties and applications compared to their protein-based counterparts. In this review, we highlight the essential physicochemical properties of polysaccharide-based wall materials for spray-dried microencapsulation of BCs including solubility, thermal stability, and emulsifying properties, rheological and film forming properties. We provide further insight into possibilities for the chemical structure modification of native wall materials and their controlled release behaviors. Finally, we summarize the most recent studies involving polysaccharide biopolymers as wall materials and/or emulsifiers in spray-dried microencapsulation of BCs.

Spray-Drying Microencapsulation of Pink Guava (Psidium guajava) Carotenoids Using Mucilage from Opuntia ficus-indica Cladodes and Aloe Vera Leaves as Encapsulating Materials

In this work, the capacity of the mucilage extracted from the cladodes of Opuntia ficus-indica (OFI) and aloe vera (AV) leaves as wall material in the microencapsulation of pink guava carotenoids using spray-drying was studied. The stability of the encapsulated carotenoids was quantified using UV-vis and HPLC/MS techniques. Likewise, the antioxidant activity (TEAC), color (CIELab), structural (FTIR) and microstructural (SEM and particle size) properties, as well as the total dietary content, of both types of mucilage microcapsules were determined. Our results show that the use of AV mucilage, compared to OFI mucilage, increased both the retention of β-carotene and the antioxidant capacity of the carotenoid microcapsules by around 14%, as well as the total carotenoid content (TCC) by around 26%, and also favors the formation of spherical-type particles (Ø ≅ 26 µm) without the apparent damage of a more uniform size and with an attractive red-yellow hue. This type of microcapsules is proposed as a convenient alternative means to incorporate guava carotenoids, a natural colorant with a high antioxidant capacity, and dietary fiber content in the manufacture of functional products, which is a topic of interest for the food, pharmaceutical, and cosmetic industries.

Microencapsulation of Essential Oils by Spray-Drying and Influencing Factors

Essential oils (EOs) are known as any aromatic oily organic substances which are naturally synthesized in plants. Exhibiting a broad range of biological activities, EOs have played a key role in numerous industries for ages, including pharmaceutical, textile, and food. However, the volatility and high sensitivity to environmental influences pose challenges to the application of EOs on industrial scale. Microencapsulation via the spray-drying method is one of the promising techniques to overcome these challenges, thanks to the presence of wall materials that properly protect the core EOs from oxidation and evaporation. By optimization of key factors related to the infeed emulsion properties and spray-drying process, the encapsulation efficiency and retention of encapsulated EOs could be significantly improved, thus allowing a wide range of EO applications. This review attempts to discuss on different determining factors of the spray-drying process to develop an effective encapsulation formula for EOs. Furthermore, recent applications of encapsulated EOs in the fields of foods, pharmaceuticals, and textile industries are also thoroughly addressed.

Essential oils encapsulated in chitosan microparticles against Candida albicans biofilms

The aim of the study was to produce and characterize chitosan microparticles loaded with essential oils (CMEOs), evaluate the essential oil (EO) release profile and the CMEOs' anti-Candida activity. The chitosan microparticles (CMs) loaded with lemongrass essential oil (LEO) and geranium essential oil (GEO) were produced by the spray-drying method and characterized regarding CMEO morphological and physicochemical parameters and EO encapsulation efficiency (EE) and release profile. The planktonic activity was quantified by broth microdilution, and the activity against biofilm was quantified by biomass formation measurement. The LEO and GEO compositions were analyzed by gas chromatography combined with mass spectrometry (GC/MS), finding the main components citral (83.17%) and citronellol (24.53%). The CMs and CMEOs showed regular distribution and spherical shape (1 to 15 μm), without any morphological and physical modifications after EO incorporation. EE% ranged from 12 to 39%. In vitro release tests demonstrated the EO release rates, after 144 h, were 33% and 55% in PBS and HCl media, respectively. The minimum inhibitory concentration (MIC) values for CMEOs were lower than for CMs and pure EOs (P < 0.05). The higher CMEO biofilm inhibition percentage demonstrates the efficiency of microparticles against Candida biofilm. These results indicate that CMEOs are promising compounds that have antibiofilm activity against C. albicans.

Instant tea from Condonopsis javanica L. root extract via spray drying

Introduction. Codonopsis javanica L. root is a gingsen-like medicinal material with valuable bioactive compounds and alkaloids in its composition. However, the diversification of commercial products from Codonopsis javanica root extract is limited and poorly represented on the market. This study presents a new production process of an instant tea product from Codonopsis javanica root extract, which involved spray drying with maltodextrin as a drying additive. Study objects and methods. The research featured different process parameters including a drying additive concentration, a drying temperature, and a feed flow rate. Moisture content and drying yield were selected as the main outcomes. Results and discussion. In general, the improved drying yield was associated with an increased drying additive concentration, a lower drying temperature, and a higher feed flow rate. The best drying yield (78.35%) was obtained at the drying additive concentration of 30% (w/w), the drying temperature of 140°C, and the feed flow rate of 300 mL/h. The total saponin content in the product was 0.29% (w/w), and the ABTS free radical scavenging ability reached 59.48 μgAA/g. The obtained powder was spherical and exhibited fairly uniform particle morphology with shriveled and concave outer surface. Conclusion. The research results justified the use of Codonopsis javanica as an ingredient in beverage industry and suggested maltodextrin as an appropriate substrate for spray-drying natural extracts.

Oxidative Stability of Green Coffee Oil (Coffea arabica) Microencapsulated by Spray Drying

In the search for oils of commercial interest that serve as new sources for the generation of cosmetic, pharmaceutical, or nutraceutical products, the green coffee beans oil (Coffea arabica L.) was studied. This research aimed to evaluate the oxidative stability of microencapsulated green coffee oil (Coffea arabica) by spray drying. The green coffee oil emulsions were produced by microfluidization using mesquite gum and octenyl succinic anhydride modified starches (OSA-starch) as wall-material. The particle size, polydispersity, and zeta potential on the microfluidized emulsions were optimized. The results showed that microfluidization had positive effects on the reduction of the emulsion droplets and the zeta potential, developing stable emulsions for both polymers. Then, the optimal microfluidization conditions were used to evaluate the impact of the spray drying conditions on the microencapsulation efficiency, morphology, and oxidation stability of the green coffee oil microcapsules under accelerated storage conditions (32% relative humidity (RH) at 25 °C). The microencapsulation efficiency was approximately 98% for both wall-materials. The morphology of the microcapsules showed spherical shapes and polydisperse sizes, a typical characteristic of spray-dried powders. The oxidative stability of the microcapsules was lower than the bulk green coffee oil (87.39 meq of O2/kg of oil), reaching values of 60.83 meq of O2/kg of oil for mesquite gum and 70.67 meq of O2/kg of oil for OSA-starch. The microcapsules produced have good potential for the development of nutraceutical foods or cosmetic formulations with adequate stability.

Recent progress in preparation and agricultural application of microcapsules

Recent advances in life science technology have prompted the need to develop microcapsule delivery systems that can encapsulate many different functional or active materials such as drugs, peptides, and live cells, etc. The encapsulation technology is now commonly used in medicine, agriculture, food, and other many fields. The application of biodegradable microcapsule systems can not only effectively prevent the degradation of core materials in the body or the biological environment, but also improve the bioavailability, control the release and prolong the halftime or storage of core active materials. Various wall materials, preparation methods, encapsulation processes, and release mechanisms are covered in this review, as well as several main factors including pH values, temperatures, particle sizes, and additives, which can strongly influence the encapsulation efficiency, the strength, and release of microcapsules. The improvement of coating materials, preparation techniques, and challenges are also highlighted, as well as application prospects.

Nanoencapsulation of lemon essential oil in Chitosan-Hicap system. Part 1: Study on its physical and structural characteristics

Lemon essential oils (LEOs) as a bioactive compound with health beneficial potential are used as safe additives in foods, medicine and nutritional supplements. However, it is a chemical compound which is sensitive to light, thermal condition and oxidation. To overcome these challenge encapsulation could be an adequate technique to protect them from degradation and evaporation. In this study, nanocapsules based on chitosan (CS) and modified starch (Hicap) with LEOs as an active ingredient was prepared by freeze-drying. The produced nanocapsules were characterized by their structural and physicochemical properties. It was found that nanocapsules produced by using CS: Hi-cap (1.5%:8.5%) clearly showed the highest encapsulation efficiency (85.44%) and Zeta potential value (+44.23mV). In vitro release studies demonstrated a prolonged release of the samples with larger CS ratio. Most nanocapsules sizes ranged from 339.3 to 553.3nm. The obtained nanocapsules showed a rough surface without the spherical shape as represented by Scanning electron microscopy images. Differential scanning calorimetry (DSC) thermogram and Fourier transform infrared (FTIR) spectroscopy techniques confirmed the success of LEOs encapsulation. The desirable physicochemical properties and thermal stability specified that such nanocapsules have promising application in delivery of LEOs in medicine and food industries.