Upscaling Osteoclast Generation by Enhancing Macrophage Aggregation Using Hollow Microgels.

Osteoclasts, the bone resorbing cells of hematopoietic origin formed by macrophage fusion, are essential in bone health and disease. However, in vitro research on osteoclasts remains challenging due to heterogeneous cultures that only contain a few multinucleated osteoclasts. Indeed, a strategy to generate homogeneous populations of multinucleated osteoclasts in a scalable manner has remained elusive. Here, the investigation focuses on whether microencapsulation of human macrophages in microfluidically generated hollow, sacrificial tyramine-conjugated dextran (Dex-TA) microgels could facilitate macrophage precursor aggregation and formation of multinucleated osteoclasts. Therefore, human mononuclear cells are isolated from buffy coats and differentiated toward macrophages. Macrophages are encapsulated in microgels using flow focus microfluidics and outside-in enzymatic oxidative phenolic crosslinking, and differentiated toward osteoclasts. Morphology, viability, and osteoclast fusion of microencapsulated cells are assessed. Furthermore, microgels are degraded to allow cell sorting of released cells based on osteoclastic marker expression. The successful encapsulation and osteoclast formation of human macrophages in Dex-TA microgels are reported for the first time using high-throughput droplet microfluidics. Intriguingly, osteoclast formation within these 3D microenvironments occurs at a significantly higher level compared to the conventional 2D culture system. Furthermore, the feasibility of establishing a pure osteoclast culture from cell transfer and release from degradable microgels is demonstrated.

A Dual Encapsulation Strategy for High-Temperature Micro PCM Particles with High Cyclic Durability.

Addressing critical issues such as high-temperature corrosion,  leakage, degradation, and subpar cyclic performance is imperative for phase change materials (PCMs), prompting the development of appropriate encapsulation techniques to surmount these challenges. In this study, a dual encapsulation strategy is proposed for high-temperature micro PCM particles. Al-Si core is microencapsulated via the "solvent evaporation-heating curing" method. Subsequently, TiO2 is employed as the skeleton material for form-stable encapsulation of PCM microcapsules by "cold pressed sintering". Detailed analysis of the crystalline phase transformation mechanism in the sintering synthesis pathway of TiO2 underscore its potential as a robust structural material with exceptional thermal stability. Furthermore, the incorporation of hexagonal boron nitride (hBN) results in a substantial enhancement of the thermal conductivity of the composites, increasing by 121.1-131.3%. The prepared form-stable phase change microcapsules (FSPCMs) are subjected to 5000 thermal cycles in the air atmosphere. There is no observed PCM leakage or composite ruptures in the FSPCM. Moreover, the oxidized mass gain is merely 3.3%, signifying exceptional oxidation resistance. Thermophysical analysis indicates that FSPCM can retain 91.3% of the enthalpy after 2000 cycles, with over 80% preservation after 5000 cycles, underscoring its remarkable cyclic thermal durability.

Amaranthus crop for food security and sustainable food systems.

MAIN CONCLUSION: This review ascertains amaranth grains as a potent crop for food security and sustainable food systems by highlighting its agricultural advantages, health benefits and applications in the food, packaging, and brewing industry. The global population surge and rapidly transitioning climatic conditions necessitate the maximization of nutritional crop yield to mitigate malnutrition resulting from food and nutrition insecurity. The modern agricultural practices adopted to maximize the yield of the conventional staple crops are heavily contingent on the depleting natural resources and are contributing extensively to the contamination of these natural resources. Furthermore, these agricultural practices are also causing detrimental effects on the environment like rising emission of greenhouse gasses and increased water footprints. To address these challenges while ensuring sustainable nutrient-rich crop production, it is imperative to utilize underutilized crops like Amaranthus. Amaranth grains are gluten-free pseudo-cereals that are gaining much prominence owing to their abundance in vital nutrients and bio-active components, potential health benefits, resilience to adverse climatic and soil conditions, minimum agricultural input requirements, potential of generating income for small holder farmers as well as various applications across the sustainable value chain. However, due to the limited awareness of these potential benefits of the amaranth grains among the consumers, researchers, and policymakers, they have remained untapped. This review paper enunciates the nutritional composition and potential health benefits of the grains while briefly discussing their various applications in food and beverage industries and accentuating the need to explore further possibilities of valorizing amaranth grains to maximize their utilization along the value chain.

Progress in Fabrication and Applications of Cholesteric Liquid Crystal Microcapsules.

Liquid crystals (LCs) are well known for inherent responsiveness to external stimuli, such as light, thermal, magnetic, and electric fields. Cholesteric LCs are among the most fascinating, since they possess distinctive optical properties due to the helical molecular orientation. However, the good flow, easy contamination, and poor stability of small-molecule LCs limit their further applications, and microencapsulation as one of the most effective tools can evade these disadvantages. Microencapsulation can offer shell-core structure with LCs in the core can strengthen their stability, avoiding interference with the environment while maintaining the stimuli-responsiveness and optical properties. Here, we report recent progress in the fabrication and applications of cholesteric LC microcapsules (CLCMCs). We summarize general properties and basic principles, fabrication methods including interfacial polymerization, in-situ polymerization, complex coacervation, solvent evaporation, microfluidic and polymerization of reactive mesogens, and then give a comprehensive overview of their applications in various popular domains, including smart fabrics, smart sensor, smart displays, anti-counterfeiting, information encryption, biomedicine and actuators. Finally, we discuss the currently facing challenges and the potential development directions in this field.

Innovative Microencapsulation of Polymyxin B for Enhanced Antimicrobial Efficacy via Coated Spray Drying.

This study aims to develop an innovative microencapsulation method for coated Polymyxin B, utilizing various polysaccharides such as hydroxypropyl ß-cyclodextrin, alginate, and chitosan, implemented through a three-fluid nozzle (3FN) spray drying process. High-performance liquid chromatography (HPLC) analysis revealed that formulations with a high ratio of sugar cage, hydroxypropyl ß-cyclodextrin (HPßCD), and sodium alginate (coded as ALGHCDHPLPM) resulted in a notable 16-fold increase in Polymyxin B recovery compared to chitosan microparticles. Morphological assessments using fluorescence labeling confirmed successful microparticle formation with core/shell structures. Alginate-based formulations exhibited distinct layers, while chitosan formulations showed uniform fluorescence throughout the microparticles. Focused beam reflectance and histograms from fluorescence microscopic measurements provided insights into physical size analysis, indicating consistent sizes of 6.8 ± 1.2 µm. Fourier-transform infrared (FTIR) spectra unveiled hydrogen bonding between Polymyxin B and other components within the microparticle structures. The drug release study showed sodium alginate's sustained release capability, reaching 26 ± 3% compared to 94 ± 3% from the free solution at the 24 h time point. Furthermore, the antimicrobial properties of the prepared microparticles against two Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, were investigated. The influence of various key excipients on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values was evaluated. Results demonstrated effective bactericidal effects of ALGHCDHPLPM against both E. coli and P. aeruginosa. Additionally, the antibiofilm assay highlighted the potential efficacy of ALGHCDHPLPM against the biofilm viability of E. coli and P. aeruginosa, with concentrations ranging from 3.9 to 500 µg/m. This signifies a significant advancement in antimicrobial drug delivery systems, promising improved precision and efficacy in combating bacterial infections.

Antibacterial effects and mechanisms of quercetin-ß-cyclodextrin complex mediated photodynamic on Escherichia coli O157:H7.

Quercetin is a natural flavonoid with antioxidant, anti-inflammatory, and antibacterial properties. This work aimed to formulate quercetin-cyclodextrin microcapsules (QT-ß-CD) while examining their photodynamic antibacterial effects and underlying mechanisms in detail. Characterization of the QT-ß-CD was conducted using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The bacteriostatic effects of UV-A irradiation on Escherichia coli O157:H7 (E. coli O157:H7) were investigated. The photodynamic impact of QT-ß-CD was assessed by analyzing hydrogen peroxide (H2O2) production. The antimicrobial activity was further elucidated through examinations of cell membrane integrity, protein damage, changes in cellular motility, biofilm formation, and extracellular polysaccharide reduction. The effect of QT-ß-CD on LuxS and motA gene expression in E. coli O157:H7 was investigated by RT-qPCR. The findings demonstrated that QT-ß-CD exhibited potent photodynamic properties and functioned as an efficient photosensitizer, causing substantial damage to E. coli O157:H7 cells. These results underscore the potential of quercetin as an antimicrobial agent for food preservation.

Evaluation of functional characteristics of Acidithiobacillus thiooxidans microencapsulated in gum arabic by spray-drying as biotechnological tool in the mining industry.

The mining and metallurgical industry represents one of the leading causes of environmental pollution. In this context, the optimization of mineral waste management and the efficient extraction of metals of interest becomes an imperative priority for a sustainable future. Microorganisms such as Acidithiobacillus thiooxidans have represented a sustainable and economical alternative in recent years due to their capacity for environmental remediation in bioleaching processes because of their sulfur-oxidizing capacity and sulfuric acid generation. However, its use has been limited due to the reluctance of mine operators because of the constant reproduction of the bacterial culture in suitable media and the care that this entails. In this work, the central objective was to evaluate the functional characteristics of A. thiooxidans, microencapsulated and stored at room temperature for three years in vacuum bags, using a spray drying process with gum arabic as a wall vector. Growth kinetics showed a survival of 80 ± 0.52% after this long period of storage. Also, a qualitative fluorescence technique with a 5-cyano-2-3 ditolyl tetrazolium (CTC) marker was used to determine the respiratory activity of the microorganisms as soon as it was resuspended. On the other hand, the consumption of resuspended sulfur was evaluated to corroborate the correct metabolic functioning of the bacteria, with results of up to 50% sulfur reduction in 16 days and sulfate generation of 513.85 ± 0.4387 ppm and 524.15 ± 0.567 ppm for microencapsulated and non-microencapsulated cultures, respectively. These results demonstrate the success after three years of the microencapsulation process and give guidelines for its possible application in the mining-metallurgical industry.

The colorful fungi of the Chilean forests: Production, chemical characterization and possible applications of their pigments.

In Chile, as in the rest of the world, only a small fraction of the fungal diversity inhabiting the wide variety of its ecosystems is known. This diversity must hide an inestimable richness of species with interesting biotechnological potential, including fungal pigment producers. Recently, interest in filamentous fungi has increased significantly due to their importance as alternative sources of pigments and colorants that are environmentally and human health friendly. As a result, fungal pigments are gaining importance in various industrial applications, such as food, textiles, pharmaceuticals, cosmetics, etc. The increasing consumer demand for "green label" natural colorants requires the exploration of different ecosystems in search of new fungal species that are efficient producers of different pigment with a wide range of colors and ideally without the co-production of mycotoxins. However, advances are also needed in pigment production processes through fermentation, scale-up from laboratory to industrial scale, and final product formulation and marketing. In this respect, the journey is still full of challenges for scientists and entrepreneurs. This chapter describes studies on pigment-producing fungi collected in the forests of central-southern Chile. Aspects such as the exploration of potential candidates as sources of extracellular pigments, the optimization of pigment production by submerged fermentation, methods of pigment extraction and purification for subsequent chemical characterization, and formulation (by microencapsulation) for potential cosmetic applications are highlighted. This potential use is due to the outstanding bioactivity of most fungal pigments, making them interesting functional ingredients for many applications. Finally, the use of fungal pigments for textile and spalting applications is discussed.

A comprehensive review on natural sweeteners: impact on sensory properties, food structure, and new frontiers for their application.

In recent years, the worldwide increase in lifestyle diseases and metabolic disorders has been ascribed to the excessive consumption of sucrose and added sugars. For this reason, many approaches have been developed in order to replace sucrose in food and beverage formulations with alternative sweetening compounds. The raising awareness concerning the synthetic sweeteners due to their negative impact on health, triggered the need to search for alternative substances. Natural sweeteners may be classified in: (i) non-nutritive (e.g., neohesperidine dihydrochalcone, thaumatin, glycyrrhizin mogroside and stevia) and (ii) bulk sweeteners, including both polyols (e.g., maltitol, mannitol, erythritol) and rare sugars (e.g., tagatose and allulose). In this review we discuss the most popular natural sweeteners and their application in the main food sectors (e.g., bakery, dairy, confectionary and beverage), providing a full understanding of their impact on the textural and sensory properties in comparison to sucrose. Furthermore, we analyze the use of natural sweeteners in blends, which in addition to enabling an effective replacement of sugar, in order to complement the merits and limits of individual compounds. Finally, microencapsulation technology is presented as an alternative strategy to solving some issues such as aftertaste, bitterness, unpleasant flavors, but also to enhance their stability and ease of use.

Genomic characterization, in vitro, and preclinical evaluation of two microencapsulated lytic phages VB_ST_E15 and VB_ST_SPNIS2 against clinical multidrug-resistant Salmonella serovars.

BACKGROUND: Salmonella infections continue to be one of the essential public health issues threatening millions of people. With the increasing occurrence of resistance against conventionally used antibiotics, the search for alternatives has become crucial. In this study, we aimed to isolate, characterize, and evaluate two lytic bacteriophages against clinically isolated multidrug-resistant (MDR) Salmonella serovars. METHODS: Screening for the phage lytic activity was performed using a spot test. Characterization of the isolated phages was done by determining the host range, longevity test, and the effect of temperature, pH, organic solvents, and morphological characterization using a transmission electron microscope. Genomic analysis was performed using Oxford nanopore sequencing. The lytic activities of the free phage lysates and formulated phage as microencapsulated were evaluated both in vitro and in vivo. RESULTS: Two phages (VB_ST_E15 and VB_ST_SPNIS2) were successfully isolated and showed lytic strong activities against MDR Salmonella (S.) Typhimurium ATCC 14,028, S. Paratyphi A, and S. Typhi. The two phages survived at the tested temperatures, maintained their infectivity for 90 days, and retained their activity until 60 °C with thermal inactivation at 65 °C. They were lytic at a pH range from 3 to 11 but lost their activities at extremely acidic or alkaline pH. The phages could withstand the organic solvents but were completely inactivated by 100% ethanol. Both phages were classified under the order Caudoviricetes, and Genus: Uetakevirus. Their genomic sequences were assembled, annotated, and submitted to the NCBI GenBank database (OR757455 and OR757456). The preclinical evaluation using the murine animal model revealed that the two-phage cocktail managed MDR Salmonella infection as evidenced by the reduction in the bacterial burden, increased animal weight, and histopathological examination. CONCLUSION: The two encapsulated phage formulas could be considered promising candidates for the management of MDR Salmonella-associated infections and clinical analysis should be undertaken to evaluate their potential use in humans.

Performance insights into spray-dryer microencapsulated Bacillus thuringiensis cry pesticidal proteins with gum arabic and maltodextrin for effective pest control.

Bacillus thuringiensis (Bt) produces crystals composed mainly of Cry pesticidal proteins with insecticidal activity against pests but are highly susceptible to degradation by abiotic factors. In this sense, encapsulation techniques are designed to improve their performance and lifetime. However, the effects of polymeric matrix encapsulation such as gum arabic and maltodextrin by spray-dryer in the mechanisms of action of Bt kurstaki and Bt aizawai are unknown. We analyzed crystal solubilization, protoxin activation, and receptor binding after microencapsulation and compared them with commercial non-encapsulated products. Microencapsulation did not alter protein crystal solubilization, providing 130 kDa (Cry1 protoxin) and 70 kDa (Cry2 protoxin). Activation with trypsin, chymotrypsin, and larval midgut juice was analyzed, showing that this step is highly efficient, and the protoxins were cleaved producing similar ~ 55 to 65 kDa activated proteins for both formulations. Binding assays with brush border membrane vesicles of Manduca sexta and Spodoptera frugiperda larvae provided a similar binding for both formulations. LC50 bioassays showed no significant differences between treatments but the microencapsulated treatment provided higher mortality against S. frugiperda when subjected to UV radiation. Microencapsulation did not affect the mechanism of action of Cry pesticidal proteins while enhancing protection against UV radiation. These data will contribute to the development of more efficient Bt biopesticide formulations. KEY POINTS: • Microencapsulation did not affect the mechanisms of action of Cry pesticidal proteins produced by Bt. • Microencapsulation provided protection against UV radiation for Bt-based biopesticides. • The study's findings can contribute to the development of more efficient Bt biopesticide formulations.

Microencapsulation of sunscreen reduces toxicity of its components to A. salina: Biochemical, behavioral and morphological studies.

Sunscreens contain several substances that cause damage to species where they are disposed. New formulations have been created to prevent such marine environmental damages. One promising formulation is the microencapsulated sunscreen. The objective of this study was to evaluate the possible safety to marine environment of one microencapsulated sunscreen formulation. The animal model Artemia salina (cists and nauplii) was tested with two sunscreen formulations (microencapsulated and non-microencapsulated) and toxicological, behavioral, morphological parameters as well as biochemical assays (lipoperoxidation and carbonylation tests) were analyzed. Results showed that microencapsulated sunscreen impeded some toxic effects caused by the release of the substances within the microcapsule in the highest concentration, reestablishing the mortality and hatching rates to control levels, while removing the sunscreen microcapsule by adding 1 % DMSO reduced the cyst hatching rate, increasing the nauplii mortality rate and decreased locomotor activity in higher concentrations. Finally, nauplii with 24 hours of life and exposed to sunscreen without the microcapsule showed an increase in mitochondrial activity (assessed at 48 hours after exposure) and presented malformations when exposed to the highest concentration non-microencapsulated concentration (assessed by SEM at 72 hours after exposure), when compared to the control group. These results together allow us to conclude that the microencapsulation process of a sunscreen helps protecting A. salina from the harmful effects of higher concentrations of said sunscreens. However, long-term studies must be carried out as it is not known how long a microencapsulated sunscreen can remain in the environment without causing harmful effects to the marine ecosystem and becoming an ecologically relevant pollutant.

Microencapsulation of natural products using spray drying; an overview.

AIMS: This study examines microencapsulation as a method to enhance the stability of natural compounds, which typically suffer from inherent instability under environmental conditions, aiming to extend their application in the pharmaceutical industry. METHODS: We explore and compare various microencapsulation techniques, including spray drying, freeze drying, and coacervation, with a focus on spray drying due to its noted advantages. RESULTS: The analysis reveals that microencapsulation, especially via spray drying, significantly improves natural compounds' stability, offering varied morphologies, sizes, and efficiencies in encapsulation. These advancements facilitate controlled release, taste modification, protection from degradation, and extended shelf life of pharmaceutical products. CONCLUSION: Microencapsulation, particularly through spray drying, presents a viable solution to the instability of natural compounds, broadening their application in pharmaceuticals by enhancing protection and shelf life.

The potential of turmeric extract-loaded chitosan microparticles for the treatment of gastrointestinal disorders.

AIM: To develop turmeric extract-loaded chitosan microparticles for treating gastrointestinal disorders. METHODS: The microparticles were prepared using a spray-drying process, optimised the characteristics by biomarker loading, and encapsulation efficiency, and assessed for bioactivities related to gastrointestinal diseases. RESULTS: The optimised microparticles were spherical, with a mean diameter of 2.11 ± 0.34 µm, a SPAN of 4.46 ± 0.68, a zeta potential of +37.6 ± 0.2 mV, loading of 15.7% w/w curcuminoids, 5.4% w/w ar-turmerone, and encapsulation efficiency of 63.26 ± 1.62% w/w curcuminoids and 43.75 ± 1.33% w/w ar-turmerone. Encapsulation of turmeric extract improved release at 6 h by 20 times and mucoadhesion by 3.6 times. The microparticles exhibited high acid-neutralising capacity (1.64 ± 0.34 mEq/g) and inhibited nitric oxide production about twice as effectively as the turmeric extract, while maintaining antioxidant and antibacterial activities. CONCLUSION: Encapsulation of turmeric extract in chitosan microparticles effectively enhanced therapeutic potential for gastrointestinal disorders.

Spray dried acerola (Malpighia emarginata DC) juice particles to produce phytochemical-rich starch-based edible films.

This study aimed to produce spray dried acerola juice microparticles with different protein carriers to be incorporated into edible starch films. The microparticles were evaluated for solids recovery, polyphenol retention, solubility, hygroscopicity, particle size distribution, X-ray diffraction, phytochemical compounds and antioxidant activity. Acerola microparticles produced with WPI/hydrolysed collagen carriers (AWC) with higher solids recovery (53.5 ± 0.34% w/w), polyphenol retention (74.4 ± 0.44% w/w), high solubility in water (85.2 ± 0.4% w/w), total polyphenol content (128.45 ± 2.44 mg GAE/g) and good storage stability were selected to produce starch-based films by casting. As a result, cassava films with water vapour permeability of 0.29 ± 0.07 g mm/m2 h KPa, polyphenol content of 10.15 ± 0.22 mg GAE/g film and DPPH radical scavenging activity of 6.57 ± 0.13 µM TE/g film, with greater migration of polyphenol to water (6.30 ± 0.52 mg GAE/g film) were obtained. Our results show that the incorporation of phytochemical-rich fruit microparticles is a promising strategy to create biodegradable edible films.

Whey/collagen protein blend AWC was the best wall material for acerola encapsulation.Spray dried protein-acerola particles were used to formulate edible films.Water soluble phenolic-rich AWC films with antioxidant properties were produced.Acerola phenolics from starch films migrated more to water than to acid media.

Encapsulation of carvacrol and thymol with yeast cell wall and its repellent activity against Amblyomma sculptum and Rhipicephalus sanguineus (Sensu Lato).

The main way to avoid contact with ticks and consequently tick-borne disease is the use of synthetic repellents. The search of new repellent compounds to increase the possibilities of use in strategies controls are necessary. The present study evaluated the repellent activity of two natural terpenes carvacrol and thymol in each one two different formulation (encapsulated and nonencapsulated with yeast cell wall) against the ticks Amblyomma sculptum and Rhipicephalus sanguineus sensu lato nymphs. Nymphs of A. sculptum and R. sanguineus s.l. of a single generation were used. The vertical filter paper repellency assay were performed with different concentration of both terpenes encapsulated and nonencapsulated in yeast cell wall. The repellent concentration 50% (RC50) were calculated to each compound formulation. Both carvacrol and thymol (encapsulated and nonencapsulated), had a repellent activity against A. sculptum and R. sanguineus s.l nymphs. Amblyomma sculptum was more sensitive to nonencapsulated carvacrol (RC50 values: 0.0032 to 0.0082 mg/cm2 after 1 and 15 min) (P < 0.05), while R. sanguineus s.l. was more sensitive to encapsulated carvacrol (RC50 values: 0.00008 to 0.0035 mg/cm2 after 1 and 15 min) (P < 0.05). Among tick species, R. sanguineus s.l. was more sensitive for most compounds than A. sculptum (P < 0.05). Although with distinct repellent activities, carvacrol and thymol encapsulated can be a promising alternative to synthetic repellents against A. sculptum and R. sanguineus s.l.

A Quantitative Re-Assessment of Microencapsulation in (Pre-Treated) Yeast.

Most hydrophobes easily diffuse into yeast cells, where they experience reduced evaporation and protection from oxidation, thus allowing inherently biocompatible encapsulation processes. Despite a long-standing industrial interest, the effect of parameters such as how is yeast pre-treated (extraction with ethanol, plasmolysis with hypertonic NaCl, depletion to cell walls), the polarity of the hydrophobes and the process conditions are still not fully understood. Here, we have developed thorough analytical protocols to assess how the effects of the above on S. cerevisiae's morphology, permeability, and encapsulation efficiency, using three differently polar hydrophobes (linalool, 1,6-dihydrocarvone, limonene) and three separate processes (hydrophobes as pure 'oils', water dispersions, or acetone solutions). The harsher the pre-treatment (depleted > plasmolyzed/extracted > untreated cells), the easier the diffusion into yeast became, and the lower both encapsulation efficiency and protection from evaporation, possibly due to denaturation/removal of lipid-associated (membrane) proteins. More hydrophobic terpenes performed worst in encapsulation as pure 'oils' or in water dispersion, but much less of a difference existed in acetone. This indicates the specific advantage of solvents/dispersants for 'difficult' compounds, which was confirmed by principal component analysis; furthering this concept, we have used combinations of hydrophobes (e.g., linalool and α-tocopherol), with one acting as solvent/enhancer for the other. Our results thus indicate advantages in using untreated yeast and-if necessary-processes based on solvents/secondary hydrophobes.

Efficiency of freeze- and spray-dried microbial preparation as active dried starter culture in kombucha fermentation.

BACKGROUND: Kombucha is a widely consumed fermented beverage produced by fermenting sweet tea with a symbiotic culture of bacteria and yeast (SCOBY). The dynamic nature of microbial communities in SCOBY may pose challenges to production scale-up due to unpredictable variations in microbial composition. Using identified starter strains is a novel strategy to control microorganism composition, thereby ensuring uniform fermentation quality across diverse batches. However, challenges persist in the cultivation and maintenance of these microbial strains. This study examined the potential of microencapsulated kombucha fermentation starter cultures, specifically Komagataeibacter saccharivorans, Levilactobacillus brevis and Saccharomyces cerevisiae, through spray-drying and freeze-drying. RESULTS: Maltodextrin and gum arabic-maltodextrin were employed as carrier agents. Our results revealed that both spray-dried and freeze-dried samples adhered to physicochemical criteria, with low moisture content (2.18-7.75%) and relatively high solubility (65.75-87.03%) which are appropriate for food application. Freeze-drying demonstrated greater effectiveness in preserving bacterial strain viability (88.30-90.21%) compared to spray drying (74.92-78.66%). Additionally, the freeze-dried starter strains demonstrated similar efficacy in facilitating kombucha fermentation, compared to the SCOBY group. The observations included pH reduction, acetic acid production, α-amylase inhibition and elevated total polyphenol and flavonoid content. Moreover, the biological activity, including antioxidant potential and in vitro tyrosinase inhibition activity, was enhanced in the same pattern. The freeze-dried strains exhibited consistent kombucha fermentation capabilities over a three-month preservation, regardless of storage temperature at 30 or 4 °C. CONCLUSION: These findings highlight the suitability of freeze-dried starter cultures for kombucha production, enable microbial composition control, mitigate contamination risks and ensure consistent product quality. © 2024 Society of Chemical Industry.

Study of Lactobacillus plantarum coated with Tremella polysaccharides to improve its intestinal adhesion.

BACKGROUND: The adhesion of probiotics to the intestine is crucial for their probiotic function. In previous studies, Tremella polysaccharides (TPS) (with sodium casein) have shown the potential to encapsulate probiotics and protect them in a simulated gastrointestinal tract. This study explored the effect of TPS (with sodium casein) on the adhesion of probiotics. RESULTS: Lactobacillus plantarum was coated with TPS and sodium casein in different proportions, and was freeze-dried. The rheological properties of the mixture of probiotics powder and mucin solution were determined by static and dynamic rheological analysis. Aqueous solutions of probiotic powder and mucin mixture exhibited pseudoplastic fluid rheological properties. The higher the proportion of TPS content, the higher the apparent viscosity and yield stress. The mixed bacterial powder and mucin fluid displayed thixotropy and was in accordance with the Herschel-Bulkley model. The TPS increased the bio-adhesive force of the probiotic powder and mucin. When using TPS as the only carbon source, the adhesion of L. plantarum to Caco-2 cells increased by 228% in comparison with glucose in vitro. Twelve adhesive proteins were also detected in the whole-cell proteome of L. plantarum. Among them, ten adhesive proteins occurred abundantly when grown with TPS as a carbon source. CONCLUSION: Tremella polysaccharides therefore possess probiotic properties and can promote the intestinal adhesion of L. plantarum. © 2024 Society of Chemical Industry.

Eco-friendly management strategies of insect pests: long-term performance of rosemary essential oil encapsulated into chitosan and gum Arabic.

This study focused on encapsulation of Rosmarinus officinalis essential oil (EO) on chitosan and gum Arabic matrix in various ratios and with varying essential oil concentrations. Additionally, UV/VIS spectroscopy was used to determine cumulative-release profiles. The insecticidal activity was tested against Tribolium castaneum and Oryzaephilus surinamensis, both pests of stored products. In terms of encapsulation efficiency (EE%) and loading capacity (LC%), capsules had EE at 45.8% and LC at 2.31%. Furthermore, many minor compounds were lost after encapsulation, until identifying only 1,8-cineole, α-terpineol, and camphor after 60 d of storage. The fumigant tests demonstrated that encapsulated EO exhibited an effective control against insect pest during storage periods, namely, 30, 45, and 60 d with 99, 66, and 46% mortality for T. castaneum and 100, 84, 82% mortality for O. surinamensis.