Microcapsule Powder Research Articles

Wood hemicelluloses as protective materials for preserving the viability of probiotic Lacticaseibacillus rhamnosus GG during spray drying

Wood hemicelluloses from forest industry side-streams are promising economic and sustainable alternatives for encapsulating bioactive compounds. This study explores their suitability for probiotic encapsulation, specifically for maintaining cell viability and structure. The ability of galactoglucomannans (GGM) and glucuronoxylans (GX) to support the survival of Lacticaseibacillus rhamnosus GG (LGG) during spray drying at solid feed concentrations of 15 and 20 % and inlet air temperatures of 105 and 140 °C (outlet air temperature of 50 °C) was investigated and compared to the results obtained using maltodextrin (MD). Across all investigated conditions, LGG survival rates exceeded 85 % (>107 cfu/g) in GX and GGM microcapsule powders, which similar to that in MD microcapsules despite the differences in pH, particle size, and viscosity of their feed dispersions. The GX microcapsules demonstrated the highest process yield (50–58 %), followed by MD (39–51 %). All the microcapsule powders exhibited an amorphous structure consisting of spherical particles with an average diameter of 10 μm, sufficient for LGG accommodation. AFM analysis confirmed the encapsulation of LGG cells within microcapsules with intact rod-shaped chains post-spray drying. Overall, the spray-dried microencapsulation of probiotics using wood hemicelluloses maintains high probiotic viability and offers an eco-friendly, cost-effective alternative to traditional materials.

Plant-based flaxseed oil microcapsules fabricated from coacervation of gluten at oil droplet surface: Microstructure, oxidation stability, and oil digestion control.

This study aimed to develop microcapsules with wheat gluten-coated oil droplets to enhance the oxidation stability and control the digestibility of flaxseed oil. The microcapsules were fabricated using a three-step procedure: (i) flaxseed oil was homogenized with an alkaline gluten solution to form oil-in-water emulsions containing small gluten-coated oil droplets (320-400nm); (ii) the pH of these emulsions was then neutralized to facilitate the deposition of gluten around the oil droplets, thereby forming a thick layer; (iii) a flaxseed oil microcapsule powder was then prepared by spray drying. During the microcapsule formation, intermolecular interactions, including hydrophobic interactions and hydrogen bonds, were involved in the coacervation of gluten at the emulsion surface. The resultant microcapsules with a multiple-core structure had external diameters of 4-26µm and encapsulation efficiencies of 90%-94%. The microencapsulated oil powders contained a relatively high flaxseed oil content (60%-80%). Among them, the sample with 60% oil content demonstrated the best stability in resisting oil droplet coalescence; thus, it exhibited a higher lipolysis rate and extent during simulated gastrointestinal digestion. A 30-day accelerated storage study showed that encapsulation of the flaxseed oil improved its resistance to oxidation. These findings suggest that the pH-deposition method can successfully produce microencapsulated polyunsaturated lipids using all plant-derived ingredients, which may facilitate their use in new plant-based foods through a green and sustainable approach.

Combining Ultra-Turrax and ultrasonic homogenization to achieve higher vitamin E encapsulation efficiency in spray drying

Vitamin E, a soluble antioxidant widely used in the food and pharmaceutical industries, is rich in tocopherols and phytosterols. Since vitamin E molecules are highly sensitive to oxidation, encapsulation is a viable and effective technique for preservation of the properties of Vitamin E and improving its stability during storage, maintaining the nutritional value. In this work, the aim was to encapsulate concentrated vitamin E using a combination of Ultra-Turrax and ultrasonication to achieve higher encapsulation efficiency in spray drying. In the first stage, the vitamin E oil was encapsulated employing only Ultra-Turrax homogenization, with subsequent optimization of spray drying. The coating materials used were maltodextrin and whey protein isolate. Optimization of the spray drying step evaluated the effects of the drying air temperature (T) and the feed flow rate (Q), to obtain better yields and a high-quality product. In the second stage, the use of ultrasonication in an additional homogenization step was evaluated, aiming to further improve the encapsulation process. The results showed that the best drying conditions (first stage) were T = 180 °C and Q = 0.6 L/h, which provided the highest yield (67.73%) and high encapsulation efficiency (73.73%). The microspheres produced had similar properties, with mean diameters ranging from 0.64 to 12.99 μm. In the second stage of the investigation, the application of ultrasonication immediately after the Ultra-Turrax homogenization enabled the encapsulation efficiency to be increased to 94.05%, with a yield of 57.54%, using an ultrasonication time of only 7 min. This showed that addition of the ultrasonic homogenization step to the process greatly improved the encapsulation efficiency and could be used to produce vitamin E-enriched powder microcapsules by spray drying, with application in the food industry.

Sustained-release effect of eggshell powder microcapsules on lavender essential oil

Eggshells are rich in Ca2+ and organic compounds, which can be taken as coupling agents for sustained-release materials. Essential oils are widely applied due to their excellent volatility, but poor sustained-release stability has limited their development. The study aimed to develop a novel eggshell powder (EP) sustained-release microcapsule, providing a new approach to protect the active ingredients of Lavender essential oil (LEO), and investigated the reasons for EP to regulate protein-polysaccharide microcapsule structure. Experimental results showed when the addition ratio of EP and Whey protein (WPI) was 1: 3, the dosage of LEO was 25%, the microcapsule displayed smooth and porous spherical structure. XRD and FT-IR indicated that a dense and orderly network structure was formed via the cross-linking reaction between eggshell powder and wall materials, which induced protein and polysaccharide to form special spherical hollow sustained-release shell structure through the calcium bridge (-COO-Ca-COO-), then achieved the sustained-release effect on LEO.

Chitosan‒gellan gum polyelectrolyte hydrogel beads containing tea tree oil microcapsules: Preparation, characterization and application

Encapsulation can be applied for essential oil protection, increasing the probability of its application in food preservation. In this study, tea tree oil (TTO) microcapsule powder (MP) was prepared by a spray‒drying approach with soy protein isolate (SPI) and fructooligosaccharide (FOS) as wall materials and were subsequently further encapsulated by chitosan (CH) and gellan gum (GG) via a polyelectrolyte complex coacervation approach. The hydrogel beads prepared with a GG mass ratio of 25% presented the best appearance and the densest internal structure. FTIR and Raman spectral analyses demonstrated the generation of hydrogen bonds between CH and GG. Thermogravimetric analysis confirmed that complex coacervates formed by CH and GG as wall materials can improve the thermal stability of TTO. Owing to the excellent barrier properties of the hydrogel beads, the hydrogel beads maintained high DPPH and ABTS free radical scavenging activities after storage. Moreover, the sustained release of TTO hydrogel beads has potential for preserving fresh-cut banana. These discoveries indicate that hydrogel beads can be used as ideal carriers of essential oils such as TTO and may be used in food preservation in the future.

Enzyme-assisted hydrolysis and microencapsulation for production of functional food with dietary fructooligosaccharides from Nam Dok Mai mango (Mangifera indica L.)

This research aimed to develop a mango juice microcapsule with high fructooligosaccharides (FOS) content using enzymatic hydrolysis with Novozym® 960 and Pectinex® Ultra SP-L. Enzymatic hydrolysis was done by varying factors which included enzyme concentration (0.1 and 0.2 mL Novozym® 960/100 mL sample and 0.5 and 1.0 mL Pectinex® Ultra SP-L/100 mL sample), incubation temperature (45–55 °C) and incubation time (60 and 120 min). Using 0.2 mL/100 mL sample of Novozym® 960 reduced sugar content by converting 80% of sucrose and increasing FOS levels by 20%. The optimal condition for spray drying increased-FOS mango juice microcapsules were established with 160 °C inlet temperature. Encapsulating agents were; resistant maltodextrin (RM), gum arabic (GA), and a combination of both at 1:1, 2:1, and 3:1 v/v ratios. Microcapsule powders exhibited a light greenish-yellow hue and optimal conditions involved a 3:1 ratio of RM and GA (GRM), which exhibited the highest phenolic compounds, flavonoid content, and antioxidant activity (p ≤ 0.05). Microcapsules stored in vacuum-sealed aluminum bags best maintained physicochemical and microbial quality over a 45-day period. Microencapsulated mango juice has potential to be used in the food industry, including its role in beverage production and as a component in functional foods.

Effects of spray drying temperature on physicochemical properties of grapeseed oil microcapsules and the encapsulation efficiency of pterostilbene

Pterostilbene (PTE) grapeseed oil emulsion was prepared by spray drying. The effects of spray drying temperature (100 °C–180 °C) on the physical properties, encapsulation efficiency of PTE, and volatile organic compounds were studied. The microcapsule powder formed at 140 °C had a high yield (53.14%), good particle integrity, and small powder particle size, and the corresponding reconstituted emulsion had a small droplet size. With the spray drying temperature increasing from 100 to 180 °C, the encapsulation efficiency of PTE in microcapsule powder decreased from 74.6% to 55.2%. The results of electronic nose and GC-IMS showed that the aroma components of grapeseed oil, such as 2-methyl butyraldehyde, 3-methyl butyraldehyde, acetone, butanone, ethanol, and 1-hexanol were well preserved after emulsification and spray drying. The results of this study are expected to promote the development of PTE-containing grapeseed oil microcapsule products for functional foods.

Double emulsion (W/O/W) microcapsule preparation of novel bacteriocin lactococcin036019 with synergistic compound vitamin C prolongs the antibacterial activity in food matrix

Application of bacteriocins in food preservation encounters the issue of activity impairment. This study intends to find a comprehensive solution to the enhancement of bacteriocin activity. Firstly, several food matrices were found to significantly reduce the antibacterial activity of bacteriocin lactococcin036019. Subsequently, vitamin C and carvacrol were both found to display a synergistic effect with bacteriocin against Staphylococcus aureus. Thereafter, double emulsion containing lactococcin036019 and vitamin C was successfully prepared. Spray drying of double emulsion with lactococcin036019 and vitamin C resulted in microcapsule powder with the particle size and entrapment efficiency of 9.10 μm and 56.18%, respectively. This microcapsule powder reduced S. aureus number by around 5 lg cfu/mL at 24 h and displayed continuous antibacterial activity in soymilk. Besides, the microcapsule powder with bacteriocin and vitamin C showed remarkable stability during storage. The double emulsion microcapsules prepared in this study demonstrate great potential in long-term preservation of food.

Effect of Blending of Shellac, Carbonyl Iron Powder, and Carbonyl Iron Powder/Carbon Nanotube Microcapsules on the Properties of Coatings

Nine sets of orthogonal experimental samples were prepared by examining four factors: shellac microcapsules, carbonyl iron powder (CIP) microcapsules, CIP/ carbon nanotube (CNT) microcapsules, and primer coating thickness. By testing the morphology and performance of the coating and using the fracture elongation of the coating as an orthogonal experimental analysis, the maximum factor affecting the fracture elongation of shellac, CIP, and CIP/CNT microcapsule coatings was determined. The first two factors that had a significant impact on the fracture elongation of the coating were the content of CIP/CNT microcapsules and shellac microcapsules. In order to further optimize the coating performance, important factor experiments were conducted, using the content of CIP/CNT microcapsules and shellac microcapsules as variables. It was found that the coating had the best performance when the content of CIP/CNT microcapsules was 7.0% and the content of shellac microcapsules was 4.0%. The optical properties of coatings with added shellac, CIP, and CIP/CNT microcapsules were tested, and the color difference and glossiness of the coatings showed little change. The mechanical properties of coatings with added shellac, CIP, and CIP/CNT microcapsules were tested. The blending of the three types of microcapsules enhanced the toughness of the coating to a certain extent, and suppressed the generation of micro-cracks, demonstrating a good self-healing effect. The electromagnetic-absorption performance of coatings with added shellac, CIP, and CIP/CNT microcapsules was tested. The blending of shellac, CIP, and CIP/CNT microcapsules exhibited two effective bands of electromagnetic absorption and a good absorption performance at a relatively wide frequency range. The combination of shellac, CIP, and CIP/CNT microcapsules endows the fiberboard surface with self-healing and electromagnetic-absorption functions, while maintaining the original performance of the water-based coating. The results can be used for application of surface coatings on wooden materials with dual functions of self-healing and electromagnetic absorption.

Preparation of Temperature-Sensitive Colour-Changing Materials and Their Applications to Clothing Fabrics: Taking a Compound Composed of Crystal Violet Lactone, Bisphenol A, and Octadecanol as an Example

A compound was prepared using crystal violet lactone, bisphenol A, and octadecanol. An in-situ polymerization method was used to prepare temperature-sensitive colour-changing microcapsules. It was printed on fabrics using printing technology. The colour-changing performance of the composite material, thermal weight changes of the microcapsules, and properties of the fabric coated with microcapsules were analyzed using cases. Printed fabric properties of colour fastness to washing, rubbing, strength and colour strength (K/S) were measured in terms of binder (%), a crosslinking agent (%), and temperature variations. The results indicated that the compound gradually changed from purple to blue within the temperature range of 3 °C to 60 °C and eventually faded into a colourless state. The weight of the microcapsule powder decreased as the temperature rose, with no significant change in weight before reaching 100 °C. Between 100 °C and 200 °C, there was a rapid decrease in weight, followed by a slow decrease between 200 °C and 350 °C. After reaching 350 °C, the weight tended to stabilize. When the mass fraction of the cross-linker was 3%, the mass fraction of the binder was 25%, and the baking temperature was 120 °C, the colour fastness, fabric strength, and K/S value (colour intensity) of the cotton fabric coated with microcapsules were optimal.

Effect of Shellac Microcapsules Blended with Carbonyl Iron Powder and Carbon Nanotubes on the Self-Healing and Electromagnetic Wave Absorption Properties of Waterborne Coatings on Fiberboard Surface

An orthogonal experiment was conducted to prepare nine different coatings by changing four influencing factors of shellac microcapsule content, carbonyl iron powder (CIP) content, the content of carbon nanotubes (CNTs), and primer coating thickness. By testing the morphology and performance of the shellac microcapsules, CIP, CNT blended coatings (SCCBC), and using the elongation at tensile failure of the SCCBC as the orthogonal experimental analysis, it was determined that the biggest factor affecting the elongation at tensile failure of SCCBC was the shellac microcapsule content. With the aim of further optimizing the properties of the SCCBC, a single-factor experiment was performed using shellac microcapsule content as the sole variable, and it was determined that the SCCBC exhibited optimal performance when shellac microcapsule content reaches 4.2%. The optical properties of SCCBC were tested, showing that there were minor fluctuations in the glossiness and color difference of the SCCBC. The mechanical properties of SCCBC were tested. The presence of shellac microcapsules can contribute to an improvement of the SCCBC toughness, restraining the formation of microcracks, and have a certain self-healing effect. The electromagnetic wave absorption properties of the mixed powder of shellac microcapsules, CIP and CNTs were tested. The CIP and CNTs can enhance the electromagnetic wave absorption properties of the waterborne coating, but the electromagnetic wave absorption properties were weaker in low-frequency bands. The SCCBC on the surface of fiberboard not only have a self-healing effect, but also have a certain electromagnetic wave absorption function through the mixing of shellac microcapsules, CIP, and CNTs, expanding the application range of waterborne coatings for wood.

Evaluation of microbial and vancomycin treatments in ulcerative colitis in murine models.

Despite the number of available therapies for ulcerative colitis (UC), severe side effects and high cost has limited their clinical application. Thus, finding new alternative strategies with minimal side effects is inevitable. Therefore, this study aimed to compare the effectiveness of different therapeutic approaches in DSS-induced colitis. Firstly, we designed oral bio-therapeutic products, Live Bacterial Products (LBP), which include a mixture of fecal bacteria strains isolated from healthy mice and prepared by microencapsulation and freeze-dried techniques. Then we investigated the efficiency of 7 days of freeze-dried FMT, LBP, and vancomycin treatments in DSS-induced colitis. Secondly, we compared the effect of 15 days of microbial therapies (freeze-dried powder of FMT and LBP microcapsules) and seven days of oral vancomycin on the severity of colitis in mice. Furthermore, the levels of IL-1β and TNF-α were measured in serum by ELISA, and the fecal microbiota diversity was analyzed by high-throughput sequencing for all mice groups. After seven days of treatments, our results indicated that oral vancomycin reduced the severity of DSS-induced colitis in mice, where weight gain and a decrease in IL-1 β and TNF-α levels were observed in the vancomycin group compared with other treatment groups. While after two weeks of treatment, the LBP microcapsules were able to reduce the severity of colitis. And at the end of the treatment period, weight gain and a decrease in the DAI scores and the levels of IL-1β and TNF-α were noted in the LBP treatment group compared to other treatment groups. By high-throughput sequencing of the 16S rRNA gene, our results showed that while the microcapsules LBP treatment increased the fecal microbial diversity, after vancomycin therapy, most of the fecal microbiota genera and operational taxonomic units (OTUs) were depleted. Our results concluded that treatment duration and preparation methods affect the microbial therapies' efficiency in UC. Furthermore, this study highlighted the negative consequences of oral vancomycin administration on gut health that should be known before using this medication.

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.

Effects of Shellac Self-Repairing and Carbonyl Iron Powder Microcapsules on the Properties of Dulux Waterborne Coatings on Wood.

Magnetic carbonyl iron powder (CIP) microcapsules were created by in situ polymerization using melamine resin as the wall material and CIP as the core material. They were mixed with shellac self-repairing microcapsules to prepare dual-functional wood coatings, and the effect of different amounts of CIP microcapsules in the Dulux Waterborne primer on the performance of the primer was investigated. The findings demonstrated that the core-wall ratio had a significant impact on the characteristics of CIP microcapsules. The microcapsule coating rate reached 57.7% when the core-wall ratio was 0.65:1. The maximum reflection loss of CIP microcapsules with the core-wall ratio of 0.70:1 is -10.53 dB. When the addition amount of shellac self-repairing microcapsules is 4.2%, and the additional amount of CIP microcapsules with a core wall ratio of 0.65:1 and 0.70:1 is 3.0%, the coating color difference is the smallest. The number of microcapsules causes a noticeable drop in the coating's gloss, and the amount of microcapsules causes a small negative change in the coating's adherence. With an increase in the number of microcapsules, the coating's hardness, impact resistance, and tensile resistance first rose and subsequently fell. When the content of CIP microcapsules with core-wall ratio of 0.65:1 and 0.70:1 was 9.0%, the hardness, elongation at break and repair rate of the coating reached the best performance. According to a comprehensive analysis, when the content of CIP microcapsules with core-wall ratio of 0.70:1 is 9.0%, the coating has good performance. At this time, the coating has a color difference of 1.83, a glossiness of 19.3, an adhesion of 2 H, a hardness of 3 H, an impact resistance of 17 kg·cm, and a repair rate of 33.3%. This provides a technical basis for the application of multifunctional coatings on wooden substrates.

Reversible thermochromic transparent bamboo for dynamically adaptive smart windows

The development of energy-saving functional materials plays a crucial role in the field of smart windows. Transparent bamboo is an emerging sustainable alternative to glass. However, the use of transparent bamboo in combination with organic thermochromic materials has not yet been thoroughly studied. In this study, reversible thermochromic transparent bamboo with dynamically temperature-adaptive functions was developed by incorporating thermochromic microcapsule powder. Reversible thermochromic transparent bamboo is colorless and has high transmittance at low temperatures, whereas it is purple with low transmittance at high temperatures providing a visually cool emotional impression. With the increase in thermochromic powder addition, the transmittance of thermochromic transparent bamboo decreased and the haze increased. When the amount of thermochromic powder was 1 wt % of the resin mass, the highest transmittance in thermochromic bamboo was 79.27 % for colorless and 63.67 % for colored. The highest tensile strength (77.79 MPa) and lowest thermal conductivity (0.225 W m−1 K−1) were obtained when the amount of powder was 3 wt %. Thermochromic transparent bamboo has excellent potential for smart window applications and its impressive haze and light absorption properties may also allow it to be used as a solar energy storage material.

Effect of gelatin and acacia gum on anthocyanin coacervated microcapsules using double emulsion and its characterization

The present study was aimed to develop a stable microencapsulated anthocyanin from black rice bran using double emulsion complex coacervation technique. Nine microcapsule formulations were prepared using gelatin, acacia gum and anthocyanin at ratios of 1:1:0.5, 1:1:0.75 and 1:1:1 respectively. The concentration of gelatin and acacia gum used were 2.5, 5 and 7.5 % w/v. Subsequently, the coacervated microcapsules were obtained at different pH (3, 3.5 and 4), freeze-dried and evaluated for their physicochemical properties, morphology, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction pattern (XRD), thermal behaviour and stability of anthocyanin. The results obtained for encapsulation efficiency of anthocyanin with high values (72.70 to 83.65 %) indicated that the encapsulation process was effective. The morphology of the microcapsule powder was analysed and exhibited round, hard, agglomerated structures and relatively smooth surface. The thermal degradation behaviour of microcapsules displayed endothermic reaction confirming the thermostability of the microcapsules where the peak ranged from 83.7 to 97.6 °C. The stability studies in terms of retention of total anthocyanin content were observed at different storage conditions; both under refrigerated condition (7 °C) and at room temperature (37 °C). The results indicated that the microcapsules obtained through coacervation can be an alternative source to develop stable nutraceuticals.

The mechanical properties of 3D printed denture base resin incorporating essential oil microcapsules.

The aim of this study was to investigate the mechanical properties of three-dimensional (3D) printed denture base resin incorporating microcapsules containing plant essential oils. Denture base specimens containing up to 3% w/v essential oil microcapsule powders (MCPs), i.e., eucalyptus, geranium, lavender, menthol, and tea tree, in two resins (Detax and NextDent 3D+) were 3D printed using two printers (Asiga and NextDent 5100). The dispersion and interaction of the MCPs in the resin were assessed by SEM while the mechanical properties of the incorporated denture base including flexural strength (MPa), flexural modulus (MPa), Vickers hardness (VHN), and surface roughness (Ra) were also subsequently evaluated. Statistical analysis of any differences in mean values was determined using a two-way ANOVA with Tukey's post hoc testing (α = .05). The spherical shape of the MCPs was maintained during the mixing and polymerization/printing process. However, the Detax-Asiga group showed significant agglomeration of the MCPs even at the lowest MCP concentration levels (0.5% w/v). Overall, as the microcapsule concentration increased, the mean flexural strength decreased, though the menthol MCP groups remained compliant with the ISO standard. The flexural modulus and harness remained relatively unchanged, and the flexural modulus complied with the ISO standard regardless of the MCP concentration. Surface roughness increased with the addition of the MCPs but also remained below that required for clinical acceptance. Incorporation of microencapsulated plant essential oils into 3D printed denture base resin was successfully achieved. While incorporation negatively influenced flexural strength and surface roughness, little effect on flexural modulus and Vickers hardness was demonstrated.

Efficacy of Talaromyces flavus microcapsule in controlling cotton important fungal diseases

Purpose: Evaluation of efficacy of Talaromyces flavus microcapsule in controlling cotton important fungal diseases and introducing Talaromyces flavus for using in the cotton fields. Methods: In this research focused on the application and efficiency evaluation of two new formulations of T. flavus microcapsules (TF-Co-G-1: Isolate 1 obtained from the Gorgan cotton farm) in suspension and powder forms, which were compared with the fungicide Talaromin® in farmers' fields. In this research, two cotton farms (Karkandeh and Hashemabad) with a history of infection with VW and DO were selected in two different regions of Golestan province. Each of the fields with an area of 1000 m2 was divided into seven equal parts. In each part, the treatments were applied separately, including microcapsule suspension with soil application, microcapsule suspension as seed impregnation, microcapsule powder with soil application, microcapsule suspension as seed impregnation, Talaromin® fungicide with soil application, Talaromin® as seed impregnation, and a control. The efficiencies of different treatments in terms of controlling the studied diseases and strengthening different growth indicators were evaluated by comparing the means of nine measured traits, including three traits for disease indicators (the percentage healthy seedlings for DO and the incidence rate and severity percentage of VW). To this end, the mixed analysis of variance (ANOVA) was first performed for two regions using the MS TAT C software, and the ANOVA of means was performed for each region separately with the significant effect of treatment × location. Results and conclusion: The results showed that among the studied formulations, powder microcapsules with seed impregnation by 32% and Talaromin® with soil application by 59% were respectively the most effective treatments for a significant increase in the percentage of healthy seedlings and a significant decrease in the severity of VW. Therefore, the obtained results indicate that the technical knowledge to produce T. flavus microcapsule formulations with two forms of suspension and powder can be transferred to manufacturing companies to carry out the commercialization and mass production process. Originality/value: Production of Talaromyces flavus microcapsule.

English

The study was carried out to produce a microcapsule powder of total flavonoids and total total phenols of methanol extract of the cashew, using a complex coacervation encapsulation method. In the search for optimal conditions for encapsulation, a three level factorial design was set up, while taking into account factors like time and proportions in Arabic gum and gelatin. The kinetic of encapsulation follows a kinetic of 2nd order which gives polynomial equations of the second degree. The conditions found are respectively 45 min, 30% Arabic gum and 70% gelatin, for an encapsulation yield is 84.37%; the encapsulation rate is 77.9% for the total flavonoids and 76.5% for the total phenols. The powder obtained has a doubled concentration in total flavonoids and total phenols than the raw bark powder.   Key words: Encapsulation, complex coacervation, total flavonoids, total phenols, Anacardium occidentale.

Effect of Urea–Formaldehyde Resin–Coated Colour–Change Powder Microcapsules on Performance of Waterborne Coatings for Wood Surfaces

Microcapsules have received a great deal of attention from researchers due to their excellent properties, and are commonly prepared by interfacial and in situ polymerisation methods. In situ polymerisation is an important method of microcapsule preparation, which has a number of advantages such as low cost and suitability for industrial production. Microencapsulation is used to modify the state of the material in order to improve its practical usability and mechanical and optical properties. In this paper, urea–formaldehyde resin–coated colour–changing powder microcapsules were prepared and their properties were used to study the colour–changing properties of wood surface coatings, and the mechanical and optical properties of waterborne paint films incorporating colour–changing powder microcapsules were tested. The results show that as the microcapsule content increases, the colour–change effect of the coating gradually becomes obvious and the amount of change in the b–value representing the yellow hue gradually increases. As the microcapsule content increased from 1.0% to 13.0%, the b–value increased from 0.7 to 2.6. The gloss of the film decreased significantly with the increase in the microcapsule content of the colour–change powder, with the highest gloss at 1.0%. The impact resistance of the film was also influenced by the content of microcapsules in the waterborne topcoat, with the best impact resistance at 5.0%, level 2 of adhesion at 1.0%–5.0% and 11.0%–13.0%, and level 1 of adhesion at 7.0% and 9.0%. In terms of mechanical and optical properties, the 5.0% content of colour–changing powder microcapsules is the best for the overall performance of waterborne topcoats. In practical furniture applications, the microcapsules prepared in this paper can change the colour in appearance according to the actual temperature and play a decorative role.