Microencapsulation Techniques Research Articles

Microencapsulation techniques for developing cannabidiol formulations: a review.

Cannabidiol (CBD), extracted from Cannabis sativa L., holds therapeutic promise without inducing psychoactive effects seen with Δ9-tetrahydrocannabinol. Its interaction with the endocannabinoid system plays a pivotal role in regulating mood, pain perception and immune function. Nevertheless, CBD encounters hurdles in clinical application due to its poor bioavailability and water solubility. To overcome these limitations, researchers are exploring microencapsulation techniques, which involve encapsulating CBD within protective matrices. This comprehensive review offers insights into various microencapsulation methods for CBD, scrutinizing their advantages, limitations and implications for formulation optimization. By elucidating the potential of microencapsulation, this review underscores its promise in refining CBD therapy and addressing challenges associated with administration.

Utilization of Microencapsulated Polyphenols to Enhance the Bioactive Compound Content in Whole Grain Bread: Recipe Optimization

In today’s health-conscious society, there is an increasing consumer demand for functional foods that not only satisfy nutritional needs but also promote overall well-being. The aim of this study was to develop a bread formulation enriched with microencapsulated polyphenols, oat β-glucan concentrate, and sour fermented beetroot juice to enhance its nutritional profile and health benefits. To protect sensitive polyphenols from thermal degradation during baking, the microencapsulation technique was employed to maintain their bioactivity. The influence of these ingredients on the physio-chemical parameters of bread (dough viscosity, hardness, porosity, bioactive ingredients content, color, and volatile compounds profiles), as well as sensory acceptability, was evaluated. Using response surface methodology, the formulation was optimized to achieve a product with high polyphenol and β-glucan content. The optimized formulation included a content of 4.60% sour fermented beetroot juice, 6.29% β-glucan concentrate, and 2.77% microencapsulated polyphenols. The final bread demonstrated significant antioxidant activity and high consumer acceptability, indicating its potential as a functional alternative to traditional bread. This innovative approach addresses the demand for healthier food options and emphasizes the role of functional ingredients in improving dietary quality and promoting health benefits.

Microencapsulation Efficiency of Carboxymethylcellulose, Gelatin, Maltodextrin, and Acacia for Aroma Preservation in Jasmine Instant Tea.

Enhancing the sensory appeal of jasmine instant tea, particularly its aroma, poses a significant challenge due to the loss of volatile organic compounds during conventional processing. This study introduces a novel approach to address this issue through the application of microencapsulation techniques, aimed at preserving these key aromatic elements. Our investigation focused on the encapsulating agents gelatin, acacia gum, carboxymethylcellulose (CMC), and maltodextrin, chosen for their compatibility with the volatile organic compounds of tea. A statistical analysis was conducted on the analytical results through comprehensive analytical techniques like Principal Component Analysis (PCA), Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA), and Variable Importance in Projection (VIP) analysis for microcapsule characterization. The statistical analysis revealed gelatin to be a particularly effective encapsulating medium, preserving an aroma profile more akin to fresh tea. The statistical analysis confirmed the reliability of these findings, highlighting the potential of microencapsulation in refining the quality of jasmine instant tea products. The results of this research suggest that microencapsulation could be instrumental in improving the sensory quality and shelf life of instant tea products, offering new opportunities for product enhancement in the beverage industry.

Oral responsive delivery systems for probiotics targeting the intestinal tract.

The increasing prevalence of health issues, driven by sedentary lifestyles and unhealthy diets in modern society, has led to a growing demand for natural dietary supplements to support overall health and well-being. Probiotic dietary supplements have garnered widespread recognition for their potential health benefits. However, their efficacy is often hindered by the hostile conditions of the gastrointestinal tract. To surmount this challenge, biomaterial-based microencapsulation techniques have been extensively employed to shield probiotics from the harsh environments of stomach acid and bile salts, facilitating their precise delivery to the colon for optimal nutritional effects. With consideration of the distinctive gastrointestinal tract milieu, probiotic delivery systems have been categorized into pH-responsive release, enzyme-responsive release, redox-responsive release and pressure-triggered release systems. These responsive delivery systems have not only demonstrated improved probiotic survival rates in the stomach, but also successful release in the intestines, facilitating enhanced adhesion and colonization of probiotics within the gut. Consequently, these responsive delivery systems contribute to the effectiveness of probiotic supplementation in intervening with gastrointestinal diseases. This review provides a comprehensive overview of the diverse oral responsive delivery systems tailored for probiotics targeting the intestinal tract. Furthermore, the review critically examines the limitations and future prospects of these approaches. This review offers valuable guidance for the effective delivery of probiotics to the intestinal tract, enhancing the potential of probiotics as dietary supplements to promote gastrointestinal health and well-being. © 2024 Society of Chemical Industry.

Enhancing the insecticidal efficacy of Allium sativum extracts through microencapsulation via complex coacervation

Garlic (Allium sativum L.) has been widely studied for its insecticidal properties. The primary bioactive molecule in garlic extracts include allicin, alliin, S-allylcysteine, diallyl disulfide, diallyl trisulfide, diallyl sulfide and ajoene. However, these compounds degrade under environmental conditions once extracted. This study aimed to enhance the effectiveness of garlic extracts in controlling Tenebrio molitor by optimizing microencapsulation techniques. The garlic extracts were encapsulated using the complex coacervation method, with independent variables including pH levels (3, 6 and 9), whey protein isolate (WPI) (4 %, 6 % and 8 % w/v) and pectin (0.50 %, 0.75 % and 1.00 % w/v). A Taguchi L9 (33) orthogonal array was employed to design 9 treatments, and T. molitor mortality was assessed 72 h after a 10 sec immersion of the insects in the treatments. Statistical analysis revealed that WPI had the most significant influence (24.52 %), followed by pH (18.82 %) and pectin (7.79 %). The interaction between pH and pectin had the greatest effect on the encapsulation process, accounting for 38.65 % of the influence. The optimal microencapsulation conditions were predicted by software to be pH 3, a pectin concentration of 0.75 % w/v and a WPI concentration of 4.00 % w/v, resulting in a signal-to-noise (S/N) ratio of 42.30. Experimental validation of these conditions produced an S/N ratio of 18.54, corresponding to a T. molitor mortality rate of 92 % ± 4.47 %. The resulting microcapsules had diameters ranging from 1–5 ?m. Complex coacervation is a highly promising method for microencapsulating garlic extracts and preserving their insecticidal properties.

Microencapsulation of Azadirachta indica oil and Tinospora cordifolia extracts blend for single-use applications

The innovative utilization of the microencapsulation technique and the antimicrobial properties of Azadirachta Indica (A.I.) and Tinospora cordifolia (T.C.) present a novel approach to producing antiseptic wipes. In this study, microcapsules with A.I. oil and T.C. extracts were synthesized and integrated into non-woven cotton fabric aiming to create disposable antiseptic medical wipes. The T.C. extract and A.I. oil were used in a 1:1 ratio and microencapsulated utilizing sodium alginate as the encapsulation material through an ionic gelation process. The optical microscope analysis of microcapsules revealed diverse microcapsule sizes, ranging from 50 μm to 180 μm in diameter and scanning electron microscopy revealed that the treated fabric has uniform distribution of microcapsules across the entire fabric surface. The antimicrobial efficacy was evaluated through disk diffusion for the extract and oil and the fabric's antimicrobial activity was assessed by measuring bacterial reduction. The treated fabric displayed substantial reductions in both Gram-positive bacteria (Staphylococcus aureus (87 %) and Bacillus cereus (99 %)) and Gram-negative bacteria (Escherichia coli (81 %) and Pseudomonas aeruginosa (99 %)). Although the treated fabric exhibited a slight decrease in whiteness (48.5–39), this alteration did not adversely affect other fabric properties. These findings underscore the potential of microencapsulated natural extracts in producing effective antimicrobial medical wipes, thereby contributing to infection control.

High‐performance self‐healing epoxy by microencapsulated epoxy‐amine chemistry II: Performance of the system

AbstractThe self‐healing epoxy based on microencapsulated epoxy‐amine chemistry is a system with great potential for practical applications. Herein, microcapsules respectively containing epoxy and polyetheramine were fabricated using a microencapsulation technique via integrating electrospraying and interfacial polymerization (ES‐IP) and self‐healing epoxy based on the dual microcapsules were systematically investigated regarding the microcapsule dispersion, healing performance, failure mode, and mechanical properties. Microcapsules with different sizes were conveniently prepared by adjusting the injection rate. The microcapsules, regardless of the size, can be well dispersed in the epoxy matrix. The effects of the microcapsule size and concentration on the healing performance were studied. While full healing can be obtained for microcapsule >100 μm, high healing efficiency of about 90% and 70% can be achieved for microcapsules in 50 ~ 100 μm and ~ 50 μm, respectively. The healing performance decreases with the decreased microcapsule concentration. However, healing efficiency >70% can still be obtained when 5.0 wt% microcapsule of 50 ~ 100 μm were adopted. Mixed failure modes including adhesive failure, cohesive failure, and matrix failure, were observed, due to the good performance of the selected healant system. While the incorporated microcapsules, especially the small ones, evidently toughens the matrix, they deteriorate the tensile properties of the formulated self‐healing material.

Advancing protein hydrolysis and phytosterol encapsulation: Emerging trends and innovations in protein-based microencapsulation techniques – A comprehensive review

Phytosterols represent a diverse and complex category of lipophilic bioactive compounds, exhibiting excellent pro-healthy properties. However, their consumption in daily diets is insufficient, and their application in food production is hindered by challenges such as low water solubility, high reactivity, and rapid degradation. The adoption of different protein or their structural modification as hydrolysates as wall material into microencapsulation techniques can be associated with improved solubility, enhanced bioaccessibility, increased bioavailability, and an extension of shelf life.This contribution provides an overview of advancements in modifying functional properties through various protein isolation methods and structural changes resulting from enzymatic hydrolysis. Additionally, the paper considers the state of the art in the utilization of various techniques and the composition of wall material in the encapsulation of phytosterols and other common lipophilic phytochemicals incorporated into delivery systems.Protein isolates obtained through novel methods of extraction may be characterized by an enhancement of their functional properties, which is crucial for the microencapsulation process. It entails not only recognizing their role as protective barriers for core materials against environmental conditions but also acknowledging their potential health-promoting attributes. These attributes encompass antioxidant properties and enhanced functional characteristics compared to native proteins. Moreover, the exploration of protein hydrolysates as versatile wall materials holds significant promise. These hydrolysates offer exceptional protective features for core materials, extending beyond mere environmental shielding. The envisioned impact extends beyond conventional delivery systems, offering transformative potential for the future of drug delivery and nutraceutical formulations.

Morphological Assessment of Thymol Essential Oil using Different Solvents and Stirring Time

Essential oils (EOs) have been used in numerous industries for ages including pharmaceutical, textile and food. Microencapsulation formulation and techniques are important to enhance the EOs characteristics and stability which could directly influence the yield and quality of EOs. This research paper evaluated the effect of using different solvents and stirring time on thymol EO microcapsules. Ethanol and methanol were used as solvents to encapsulate the core and wall material using a simple coacervation method. The microcapsules were collected at various time intervals which were 15, 30, 45, 60, 90, 120, 150, and 180 minutes. It has been noted that the stirring time influenced the size of microcapsules. Using Thymol oil, ethyl cellulose, methanol and polyvinyl alcohol (TM) produces the most microcapsules at 120 minutes of stirring time. The biggest microcapsule diameter was recorded at 90 min stirring time using formulation of thymol oil, ethyl cellulose, ethanol, and polyvinyl alcohol (TE). The encapsulation efficiency (EE) of both samples are 64.55% and 72.16%, respectively.

Effects of microencapsulated plant essential oils on growth performance, immunity, and intestinal health of weaned Tibetan piglets.

Plant essential oils (PEOs) have received significant attention in animal production due to their diverse beneficial properties and hold potential to alleviate weaning stress. However, PEOs effectiveness is often compromised by volatility and degradation. Microencapsulation can enhance the stability and control release rate of essential oils. Whether different microencapsulation techniques affect the effectiveness remain unknown. This study aimed to investigate the effects of PEOs coated by different microencapsulation techniques on growth performance, immunity, and intestinal health of weaned Tibetan piglets. A total of 120 Tibetan piglets, aged 30 days, were randomly divided into five groups with four replicates, each containing six piglets. The experimental period lasted for 32 days. The groups were fed different diets: a basal diet without antibiotics (NC), a basal diet supplemented with 10 mg/kg tylosin and 50 mg/kg colistin sulfate (PC), 300 mg/kg solidified PEO particles (SPEO), 300 mg/kg cold spray-coated PEO (CSPEO), or 300 mg/kg hot spray-coated PEO (HSPEO). The results showed that supplementation with SPEO, CSPEO, or HSPEO led to a notable decrease in diarrhea incidence and feed to gain ratio, as well as duodenum lipopolysaccharide content, while simultaneously increase in average daily gain, interleukin-10 (IL-10) levels and the abundance of ileum Bifidobacterium compared with the NC group (p < 0.05). Supplementation with SPEO, CSPEO, or HSPEO significantly elevated serum immunoglobulin G (IgG) levels and concurrently reduced serum lipopolysaccharide and interferon γ levels compared with the NC and PC groups (p < 0.05). Serum insulin-like growth factor 1 (IGF-1) levels in the SPEO and HSPEO groups significantly increased compared with the NC group (p < 0.05). Additionally, CSPEO and HSPEO significantly reduced jejunum pH value (p < 0.05) compared with the NC and PC groups (p<0.05). Additionally, Supplementation with HSPEO significantly elevated levels of serum immunoglobulin M (IgM) and interleukin-4 (IL-4), abundance of ileum Lactobacillus, along with decreased serum interleukin-1 beta (IL-1β) levels compared with both the NC and PC groups. Our findings suggest that different microencapsulation techniques affect the effectiveness. Dietary supplemented with PEOs, especially HSPEO, increased growth performance, improved immune function, and optimized gut microbiota composition of weaned piglets, making it a promising feed additive in piglet production.

Effects of Resistant-Starch-Encapsulated Probiotic Cocktail on Intestines Damaged by 5-Fluorouracil.

Probiotics and prebiotics have gained attention for their potential health benefits. However, their efficacy hinges on probiotic survival through the harsh gastrointestinal environment. Microencapsulation techniques provide a solution, with resistant starch (RS)-based techniques showing promise in maintaining probiotic viability. Specifically, RS-encapsulated probiotics significantly improved probiotic survival in gastric acid, bile salts, and simulated intestinal conditions. This study investigated the effects of a resistant-starch-encapsulated probiotic cocktail (RS-Pro) in the context of 5-fluorouracil (5-FU) chemotherapy, which frequently induces microbiota dysbiosis and intestinal mucositis. Female BALB/c mice were divided into three groups: a 5-FU group, a 5-FU+Pro group receiving free probiotics, and a 5-FU+RS-Pro group receiving RS-encapsulated probiotics. After 28 days of treatment, analyses were conducted on fecal microbiota, intestinal histology, peripheral blood cell counts, and body and organ weights. It was revealed by 16S rRNA MiSeq sequencing that 5-FU treatment disrupted gut microbiota composition, reduced microbial diversity, and caused dysbiosis. RS-Pro treatment restored microbial diversity and increased the population of beneficial bacteria, such as Muribaculaceae, which play roles in carbohydrate and polyphenol metabolism. Furthermore, 5-FU administration induced moderate intestinal mucositis, characterized by reduced cellularity and shortened villi. However, RS-Pro treatment attenuated 5-FU-induced intestinal damage, preserving villus length. Mild leukopenia observed in the 5-FU-treated mice was partially alleviated in 5-FU+Pro and 5-FU+RS-Pro groups. These findings suggest that RS-Pro may serve as an adjunct to chemotherapy, potentially reducing adverse effects and improving therapeutic outcomes in future clinical applications.

Microencapsulation: A Review

A process known as "microencapsulation" forms thin wall material coverings around things, which can be gases, liquids, or even solids, and encases them in tiny particles. Small entities with an active ingredient known as the core material encased in a covering substance or embedded in a matrix structure are known as microencapsulated products, or micro particles. The overview includes information on encapsulating materials, preparation methods, the physics of release through the capsule wall, microcapsule characterization, and the many applications of microcapsules. The review, "State of Art of Microencapsulation of Microcapsule Preparation Process Technology," is a reputable resource on the creation, characteristics, and applications of novel small particles that are individually encapsulated. It also covers popular microencapsulation techniques and their benefits and drawbacks, as well as the broader applications of these techniques in the fields of pharmaceuticals, cosmetics, agriculture, food technologies, and textiles.

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.

Embedding Bioprinting of Low Viscous, Photopolymerizable Blood-Based Bioinks in a Crystal Self-Healing Transparent Supporting Bath.

Protein-based hydrogels have great potential to be used as bioinks for biofabrication-driven tissue regeneration strategies due to their innate bioactivity. Nevertheless, their use as bioinks in conventional 3D bioprinting is impaired due to their intrinsic low viscosity. Using embedding bioprinting, a liquid bioink is printed within a support that physically holds the patterned filament. Inspired by the recognized microencapsulation technique complex coacervation, crystal self-healing embedding bioprinting (CLADDING) is introduced based on a highly transparent crystal supporting bath. The suitability of distinct classes of gelatins is evaluated (i.e., molecular weight distribution, isoelectric point, and ionic content), as well as the formation of gelatin-gum arabic microparticles as a function of pH, temperature, solvent, and mass ratios. Characterizing and controlling this parametric window resulted in high yields of support bath with ideal self-healing properties for interaction with protein-based bioinks. This support bath achieved transparency, which boosted light permeation within the bath. Bioprinted constructs fully composed of platelet lysates encapsulating a co-culture of human mesenchymal stromal cells and endothelial cells are obtained, demonstrating a high-dense cellular network with excellent cell viability and stability over a month. CLADDING broadens the spectrum of photocrosslinkable materials with extremely low viscosity that can now be bioprinted with sensitive cells without any additional support.

Recent microencapsulation trends for enhancing the stability and functionality of anthocyanins: a review.

Anthocyanins (ACNs) are water-soluble pigments in various fruits and vegetables known for their high antioxidant activity. They are used as natural food colorants and preservatives and have several medicinal benefits. However, their application in functional foods and nutraceuticals is often compromised by their low stability to heat, oxygen, enzymes, light, pH changes, and solubility issues. Spray drying has emerged as an effective microencapsulation technique to enhance the shelf life, quality, and stability of ACNs. This manuscript reviews the latest scientific developments in spray drying microencapsulation of ACNs-rich fruit extracts. Process optimization and the stability and physicochemical properties of the spray-dried, microencapsulated ACNs-rich powders are discussed. This review also covers functional food and nutraceutical applications and introduces novel encapsulation methods, such as freeze-drying, supercritical carbon dioxide (SC-CO2), coacervation, drum drying, and electrospraying, highlighting their potential in improving the utility of ACNs-rich fruit extracts.

A Brief Review on the Current Trends in Microencapsulation

Microencapsulation has emerged as a pivotal technology in the field of novel drug delivery systems (NDDS), offering significant advantages in enhancing the efficacy, safety, and patient compliance of therapeutic agents. This cutting-edge technique involves encapsulating active pharmaceutical ingredients (APIs) within microscopic protective coatings, enabling controlled release, targeted delivery, and improved bioavailability. Microencapsulation has proven to be a versatile tool in addressing various pharmaceutical challenges, such as masking unpleasant tastes, protecting sensitive drugs from degradation, and modifying the absorption site of drugs. This comprehensive review aims to provide an in-depth understanding of microencapsulation, its principles, techniques, and diverse applications in the pharmaceutical industry. The article delves into the reasons for employing microencapsulation, including extended or sustained drug release, taste and odor masking, conversion of liquids into free-flowing powders, and stabilization of light, moisture, or oxygen-sensitive drugs. Additionally, the classification of microparticles based on their core and shell materials is discussed. Furthermore, the review explores the advantages and disadvantages of microencapsulation, highlighting its ability to protect encapsulated active agents, transform gases and liquids into solid particles, modify surface and colloidal properties, and alter the release profiles of drugs. Various microencapsulation techniques are extensively covered, including air suspension, coacervation phase separation, pan coating, spray drying and spray congealing, and solvent evaporation. The applications of microencapsulation span across diverse industries, such as pharmaceuticals, cosmetics, agrochemicals, and food. This review provides insights into the utilization of microencapsulated products in these sectors, emphasizing their role in enhancing product functionality, stability, and controlled release

Microwave-assisted extraction, encapsulation, and bioaccessibility of carotenoids from organic tomato industry by-product

Tomato (Solanum lycopersicum) is a widely consumed fruit in the world. Discarded biomass has a huge potential, as tomato peel is rich in carotenoid content. This study focuses on the recovery of carotenoids from tomato industry agro-wastes, specifically peel and seeds. Initially, the conventional method was employed to analyze the sample, determining a total carotenoid content of 3.19 ± 0.23 mg β-carotene eq/g dry matter. A carotenoid profiling of the sample revealed high concentration of 5-cis-lycopene (1340.1 ± 15.6 μg all-trans-β-carotene eq/g dry matter), 9-cis lycopene (1062.7 ± 12.8 μg all-trans-β-carotene eq/g dry matter) and all-trans-β-carotene (1246.4 ± 1.7 μg all-trans-β-carotene eq/g dry matter). Microwave-assisted extraction (MAE) was employed as a green extraction method to optimize biomass-solvent ratio (BSR), extraction time (ET), and microwave power (MP) for achieving maximum recovery of carotenoids. A surface response methodology based on a Box-Behnken design was used. The optimized extract (BSR 1:10 g:mL, ET 60 s, and MP 283.84 W) was microencapsulated using maltodextrin (MD) combined with either gum arabic (GA) or whey protein isolate (WP) as wall materials. Freeze-drying was utilized for capsule sealing. The properties of the encapsulates were characterized, including moisture content (0.99 ± 0.04% for MD:GA and 0.80 ± 0.07% for MD:WP), water activity (0.087 ± 0.01 for MD:GA and 0.084 ± 0.01 for MD:WP), dissolution rate (140.4 1 ± 6.41 s for MD:GA and 86.49 ± 1.68 s for MD:WP), tapped density (0.48 ± 0.01 g/mL for MD:GA and 0.44 ± 0.01 g/mL for MD:WP), drying yield (90.73 ± 3.34% for MD:GA and 89.73 ± 3.47% for MD:WP), and encapsulation efficiency (68.12 ± 1.42% for MD:GA and 74.55 ± 1.62% for MD:WP). Bioaccessibility studies for encapsulated extract revealed values of 27.68% ± 0.72 and 25.10% ± 0.04 for MD:GA and MD: WP, respectively. This research highlights the potential of tomato agro-wastes as a valuable source of bioactive compounds. The implementation of MAE and microencapsulation techniques demonstrates effective strategies for their recovery and preservation obtaining the optimal conditions for the MAE (BSR 1:10 g: mL, ET 60 s, and MP 283.84 W) and for the encapsulation (MD: WP mixture). These findings contribute to the valorization of tomato industry by-products and their potential application in functional food products.

Chitosan for improved encapsulation of thyme aqueous extract in alginate-based microparticles

Ionotropic gelation is a low-cost, easy and green microencapsulation technique. However, the encapsulation of highly soluble compounds is challenging because of the wide loss of material into the external water phase by passive diffusion and the consequent low encapsulation efficiency. In this work an important increase of encapsulation efficiency for Thymus vulgaris L. aqueous extract in alginate-based microparticles has been obtained. A formulation with the proper thyme extract/alginate ratio (30:70) was used as reference and then optimized by adding different co-carrier excipients. Microparticles obtained by dropping a solution containing thyme extract and alginate into a chitosan/calcium-chloride/acid acetic solution lead to a high encapsulation efficiency (70.43 ± 5.28 %). After drying, microparticles had a particle size of 1096 ± 72 μm, 20.087 ± 1.487 % of extract content, 6.2 % of residual water, and showed a complete release of thyme extract within one hour. Combining alginate and chitosan as polymeric co-carrier was a valuable option for efficiently encapsulating an aqueous extract by ionotropic gelation.

Energy Storage in Lightweight Aggregate and Pervious Concrete Infused with Phase Change Materials

This study explores the feasibility of utilizing pervious concrete (PC) incorporating diverse lightweight aggregates (LWAs) integrated with phase change materials (PCM) for applications where forced air cooling would be advantageous. The use of such a component provides latent and sensible heat that can cool forced air applications, offsetting ambient temperature increases that occur during the day. Macro- and microencapsulation techniques were used to incorporate inorganic PCM in the PC. The macro-encapsulation technique involved enclosure of PCM within a stable shell prior to addition into the concrete. The microencapsulation technique involved the impregnation of PCM into porous lightweight aggregate. To overcome the PCM reaction with the concrete constituents, an epoxy coating was utilized. The design of the PCM concrete mix and comprehensive laboratory assessment of porosity, water permeability, PCM absorption capacity, compressive strength, and microstructure of the LWAs are detailed. The test results indicate that LWAs have high PCM impregnation rates ranging from 32 % to 57 % by volume. The compressive strengths of PC using LWAs were reduced by 25 % to 65 % when using microencapsulation. The use of microencapsulation was found to reduce the pressure drop under air flow due to the increase in aggregate size as a result of the coating thickness. PCM-PC with a shell thickness of 100 mm, resulted in a pressure drop of less than 100 Pa at a velocity of 0.35 m/s. The use of macro-encapsulated PCM in PC was sensitive to the phase of the PCM, where the liquid phase reduced the compressive strength by 67 %. The failure occurred within the macro-encapsulated PCM at the liquid phase temperatures and at the interface between the encapsulated PCM at solid phase temperatures. The heat transfer provided by the LWA infused PCM when used in a packed aggregate bed or in PC, was shown to match expected latent and sensible heat estimates based on the thermal properties of the materials. This systematic investigation provides valuable insights into LWAs and PCM performance in pervious concrete, offering a comprehensive understanding of their interaction in cooling applications.

Advanced fabrication of complex biopolymer microcapsules via RSM-optimized supercritical carbon dioxide solution-enhanced dispersion: A comparative analysis of various microencapsulation techniques

This work aimed to enhance hemp seed oil encapsulation within a hemp seed protein-alginate complex by optimizing parameters in the solution-enhanced dispersion process, employing supercritical carbon dioxide (SEDS) without reliance on organic solvents or elevated temperatures. By response surface methodology (RSM), the microencapsulation efficacy (MEE), particle size (PS) and peroxide value (PV) was determined with respect to three parameters; temperature (°C), pressure (bar) and feed flow rate (mL/min). The optimum conditions were predicted at temperature (40 °C), pressure (150 bar) and feed flow rate (2 mL/min) to offer an MEE of 89.47%, PS of 7.81 μm and PV of 2.91 (meq/kg oil). In addition, the SEDS method was compared with spray- and freeze-drying for encapsulating hemp seed oil. The findings demonstrated SEDS' superiority, exhibiting exceptional attributes such as the highest MEE, smallest PS and the production of spherical, smooth microcapsules. This highlights its effectiveness in comparison to spray- and freeze-drying methods.