Lactobacillus casei Encapsulated in Soy Protein Isolate and Alginate Microparticles Prepared by Spray Drying

Effect of Encapsulation of Lactobacillus casei in Alginate-Tapioca Flour Microspheres Coated with Different Biopolymers on the Viability of Probiotic Bacteria

To realize the health benefits of probiotic bacteria, they must withstand processing and storage conditions and remain viable after use. The encapsulation of these probiotics in the form of microspheres containing tapioca flour as a prebiotic and vehicle component in their structure or shell affords symbiotic effects that improve the survival of probiotics under unfavorable conditions. Microencapsulation is one such method that has proven to be effective in protecting probiotics from adverse conditions while maintaining their viability and functionality. The aim of the work was to obtain high-quality microspheres that can act as carriers of Lactobacillus casei bacteria and to assess the impact of encapsulation on the viability of probiotic microorganisms in alginate microspheres enriched with a prebiotic (tapioca flour) and additionally coated with hyaluronic acid, chitosan, or gelatin. The influence of the composition of microparticles on the physicochemical properties and the viability of probiotic bacteria during storage was examined. The optimal composition of microspheres was selected using the design of experiments using statistical methods. Subsequently, the size, morphology, and cross-section of the obtained microspheres, as well as the effectiveness of the microsphere coating with biopolymers, were analyzed. The chemical structure of the microspheres was identified by using Fourier-transform infrared spectrophotometry. Raman spectroscopy was used to confirm the success of coating the microspheres with the selected biopolymers. The obtained results showed that the addition of tapioca flour had a positive effect on the surface modification of the microspheres, causing the porous structure of the alginate microparticles to become smaller and more sealed. Moreover, the addition of prebiotic and biopolymer coatings of the microspheres, particularly using hyaluronic acid and chitosan, significantly improved the survival and viability of the probiotic strain during long-term storage. The highest survival rate of the probiotic strain was recorded for alginate-tapioca flour microspheres coated with hyaluronic acid, at 5.48 log CFU g-1. The survival rate of L. casei in that vehicle system was 89% after storage for 30 days of storage.

Microencapsulation of riboflavin-producing Lactiplantibacillus Plantarum MTCC 25,432 and Evaluation of its Survival in Simulated Gastric and Intestinal Fluid

Microencapsulation is an optimistic method for the delivery of live microbial cells through different food products. In this study, riboflavin-producing probiotic strain Lactiplantibacillus plantarum MTCC 25,432 was encapsulated using a spray drying technique with different wall materials including Inulin, maltodextrin (MD), and MD + Inulin (1:1). The obtained spray dried powder was investigated for probiotic viability, encapsulation efficiency, particle size, water activity, moisture content, hygroscopicity, bulk and tapped densities, storage stabilities, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Besides this, the viability of the free and encapsulated probiotic cells was tested under simulated gastric and intestinal fluid conditions. In the results, microcapsules produced with the combination of MD + Inulin showed higher dry powder yield (36.5%) and viability of L. plantarum MTCC 25,432 (7.4 log CFU / g) as compared with individual coating materials. Further characterization revealed that MD + Inulin microcapsules are spherical (3.50 ± 1.61 μm in diameter) in shape with concavities, showed the highest encapsulation efficiency (82%), low water activity (0.307), moisture content (3.67%) and good survival ability at low pH (pH 2.0 and 3.0), high bile salt concentrations (1.0% and 2.0%), and long storage conditions. No differences in FTIR spectra were observed among the tested samples. However, TGA showed enhanced thermal stability of probiotic-loaded microcapsules when MD + Inulin was used together. In conclusion, MD + Inulin could be a potential encapsulation material for riboflavin-producing probiotic bacteria L. plantarum MTCC 25,432.

Survivability and behavior of probiotic bacteria encapsulated by internal gelation in non-dairy matrix and In Vitro GIT conditions

The primary objective of this investigation was to assess the viability of free and encapsulated Lactobacillus plantarum probiotics in mango juice and under simulated gastrointestinal conditions. Specifically, the probiotics were encapsulated using sodium alginate and alginate-soy protein isolate through the internal gelation method, and the obtained probiotics were characterized for various attributes. Both free and encapsulated probiotics were exposed to challenging conditions, including thermal stress, low temperature, and simulated gastrointestinal conditions. Additionally, both types of probiotics were incorporated into mango juice, and their survival was monitored over a 28-day storage period. Following viability under simulated gastrointestinal conditions, the count of free and encapsulated probiotic cells decreased from initial levels of 9.57 log CFU/mL, 9.55 log CFU/mL, and 9.53 log CFU/mL, 9.56 log CFU/mL to final levels of 6.14 log CFU/mL, 8.31 log CFU/mL, and 6.24 log CFU/mL, 8.62 log CFU/mL, respectively. Notably, encapsulated probiotics exhibited a decrease of 1.24 log CFU and 0.94 log CFU, while free cells experienced a reduction of 3.43 log CFU and 6.24 log CFU in mango juice over the storage period. Encapsulated probiotics demonstrated higher viability in mango juice compared to free probiotics throughout the 28-day storage period. These findings suggest that mango juice can be enriched with probiotics to create a health-promoting beverage.

Improving probiotic survival using water-in-oil-in-water (W1/O/W2) emulsions: Role of fish oil in inner phase and sodium alginate in outer phase

Aqueous probiotic suspensions were dispersed in an oil phase consisting of fish oil and medium chain triglycerides to form W₁/O emulsions. These emulsions were then homogenized with an aqueous solution containing soybean protein isolate and sodium alginate to form W₁/O/W₂ emulsions. Fish oil was used to promote the growth of the probiotics and increase their ability to adhere to the intestinal mucosa. Sodium alginate increased the viscosity, stability, and probiotic encapsulation efficiency of the double emulsions, which was mainly attributed to its interactions with adsorbed soy proteins. The encapsulation efficiency of the probiotics in the double emulsions was relatively high (>96%). In vitro simulated digestion experiments showed that the double emulsions significantly increased the number of viable probiotics remaining after passing through the entire gastrointestinal tract. This study suggests that encapsulation of probiotics in double emulsions may increase their viability under gastrointestinal conditions, thereby enhancing their efficacy in functional foods.

Microencapsulation of Yarrowia lipolytica: cell viability and application in vitro ruminant diets

Microencapsulation is an alternative to increase the survival capacity of microorganisms, including Yarrowia lipolytica, a widely studied yeast that produces high-value metabolites, such as lipids, aromatic compounds, biomass, lipases, and organic acids. Thus, the present study sought to investigate the effectiveness of different wall materials and the influence of the addition of salts on the microencapsulation of Y. lipolytica, evaluating yield, relationship with cell stability, ability to survive during storage, and in vitro application of ruminant diets. The spray drying process was performed via atomization, testing 11 different compositions using maltodextrin (MD), modified starch (MS) and whey protein concentrate (WPC), Y. lipolytica (Y. lipo) cells, tripolyphosphate (TPP), and sodium erythorbate (SE). The data show a reduction in the water activity value in all treatments. The highest encapsulation yield was found in treatments using MD + TPP + Y. lipo (84.0%) and WPC + TPP + Y. lipo (81.6%). Microencapsulated particles showed a survival rate ranging from 71.61 to 99.83% after 24 h. The treatments WPC + Y. lipo, WPC + SE + Y. lipo, WPC + TPP + Y. lipo, and MD + SE + Y. lipo remained stable for up to 105 days under storage conditions. The treatment WPC + SE + Y. lipo (microencapsulated yeast) was applied in the diet of ruminants due to the greater stability of cell survival. The comparison between the WPC + SE + Y. lipo treatment, wall materials, and the non-microencapsulated yeast showed that the microencapsulated yeast obtained a higher soluble fraction, degradability potential, and release of nutrients.

Development of a microecologic product from Lactobacillus rhamnosus based on silica

BACKGROUND

Probiotics are primarily made into microecologic products for use in the food and feed industries. The freeze-drying technique is widely used in their preparation to maintain their high level of bioactivity. This causes high costs in terms of the energy and time needed. In this study, we developed a method to produce a highly active microecologic product from Lactobacillus rhamnosus using heating and silica.

RESULTS

A microecologic product was made successfully from L. rhamnosus using the whole bacterial culture broth, without waste, and using food-grade silica (4.5 mL g^-1 ) to absorb water before drying at 37 °C for 8 h. The activity of L. rhamnosus cells was increased significantly by adding water extracts of green tea to the culture medium. The viable amount of L. rhamnosus in the obtained microecologic product was 9.80 × 10¹⁰  cfu g^-1 with a survival rate of 224.67% in simulated gastric juice for 3 h and 68.2% in simulated intestinal juice for 3 h. The microecologic product treated an intestinal infection by multi-drug-resistant Staphylococcus aureus in mice very efficiently.

CONCLUSION

The study developed an economic, eco-friendly, and efficient method for preparing highly active microecologic agents using heating and without waste. © 2022 Society of Chemical Industry.

The Correlation Between the DMFT of the 15-year-old Children and the Concentration of Fluoride in Drinking Water from the East Region of the Republic of Macedonia

AIM: The aim of this study is to determine the correlation between the DMFT index of 15-year-old children from the east region and the concentration of fluoride in drinking water from the populated areas where children live. METHODS: In the examination, 414 children were enrolled, out of seven central secondary schools from four bigger cities from east region, at which the DMFT index was determined. The children live in six different cities and 51 different villages. Fifty-seven water samples were taken from the examined area to determine the fluoride concentration using the electrochemical method using the pH/ISE meter-Thermo-Orion with a special F-electrode (Thermo Orion Ion Plus Fluoride Electrode) at the Institute for public health. Spearman’s method was used to determine the correlation between the specified variables. RESULTS: The total number of children in the examined sample was 414, out of which 226 (54.6%) were male and 188 (45.4%) were female. The prevalence of caries free children was 9.4%. SiC index was 10.22. The average DMFT index in this group of children was 5.77 with a standard deviation of ± 4.02. Maximum concentration of fluorine in drinking water of 0.99 ppmF was determined in the village Raslovci, and 0.87 ppmF in the village Star Karaorman, while the minimum (0.07 ppmF) in the village Dvorishte and (0.10 ppmF) in the village Grad. Correlation of the DMFT index in 15-year-old children from the east region and the concentration of fluorine in the drinking water has a negative, indirect correlation, with the value of the coefficient R = −0.27. CONCLUSION: The correlation between the DMFT index and the concentration of drinking water is a negative, indirect correlation, and statistically, this correlation is highly significant (p < 0.05).

Materials Used for the Microencapsulation of Probiotic Bacteria in the Food Industry

Probiotics and probiotic therapy have been rapidly developing in recent years due to an increasing number of people suffering from digestive system disorders and diseases related to intestinal dysbiosis. Owing to their activity in the intestines, including the production of short-chain fatty acids, probiotic strains of lactic acid bacteria can have a significant therapeutic effect. The activity of probiotic strains is likely reduced by their loss of viability during gastrointestinal transit. To overcome this drawback, researchers have proposed the process of microencapsulation, which increases the resistance of bacterial cells to external conditions. Various types of coatings have been used for microencapsulation, but the most popular ones are carbohydrate and protein microcapsules. Microencapsulating probiotics with vegetable proteins is an innovative approach that can increase the health value of the final product. This review describes the different types of envelope materials that have been used so far for encapsulating bacterial biomass and improving the survival of bacterial cells. The use of a microenvelope has initiated the controlled release of bacterial cells and an increase in their activity in the large intestine, which is the target site of probiotic strains.

Novel Developments on Stimuli-Responsive Probiotic Encapsulates: From Smart Hydrogels to Nanostructured Platforms

Biomaterials engineering and biotechnology have advanced significantly towards probiotic encapsulation with encouraging results in assuring sufficient bioactivity. However, some major challenges remain to be addressed, and these include maintaining stability in different compartments of the gastrointestinal tract (GIT), favoring adhesion only at the site of action, and increasing residence times. An alternative to addressing such challenges is to manufacture encapsulates with stimuli-responsive polymers, such that controlled release is achievable by incorporating moieties that respond to chemical and physical stimuli present along the GIT. This review highlights, therefore, such emerging delivery matrices going from a comprehensive description of addressable stimuli in each GIT compartment to novel synthesis and functionalization techniques to currently employed materials used for probiotic’s encapsulation and achieving multi-modal delivery and multi-stimuli responses. Next, we explored the routes for encapsulates design to enhance their performance in terms of degradation kinetics, adsorption, and mucus and gut microbiome interactions. Finally, we present the clinical perspectives of implementing novel probiotics and the challenges to assure scalability and cost-effectiveness, prerequisites for an eventual niche market penetration.

Fish oil encapsulated in soy protein particles by lyophilization. Effect of drying process

BACKGROUND

Fish oil is an important source of healthy ω-3 fatty acids to be used in functional foods. However, its autoxidation susceptibility, aroma and solubility make it difficult to use. Its encapsulation could reduce these disadvantages. This manuscript focuses on the drying stage of the encapsulation process. Its objective was to study the encapsulation of fish oil with soy proteins by emulsification and lyophilization and compare microparticles characteristics with those processed identically but spray dried.

RESULTS

Microparticles with different protein/oil ratios were prepared by emulsification and lyophilization. Soy proteins encapsulated fish oil in matrix-type microcapsules masking its typical odor and oily appearance. Microparticles dried by lyophilization showed a better solid recovery but lower encapsulation efficiency than those spray dried. Increasing protein/oil mass ratio of initial formulations seemed to favor initial lipid oxidation, but these differences were not appreciated when analyzing the oxidative stability over time (measured by Rancimat test). Porous structure and large surface area of lyophilized samples would favor oxygen easy penetration and exposition to free radicals, increasing lipid oxidation over time, while spray dried microparticles showed a good oxidative stability over time, like that of free oil.

CONCLUSION

Drying processes were determinants in the morphology of microcapsules, the efficiency of encapsulation and protection exerted on the oil. Although emulsifying and drying processes caused certain initial oil oxidation, soy proteins managed to mask fish oil flavors and spray dried systems showed a good perspective of oxidative stability of fish oil over time, better than that of lyophilized microparticles. © 2021 Society of Chemical Industry.

A Laser Irradiation Method for Controlling Pieris rapae Larvae

At present, chemical pesticides remain the main approach for controlling Pieris rapae (L.) (Lepidoptera: Pieridae). This research proposes a novel laser irradiation method for managing P. rapae larvae as an alternative to chemical control. The effectiveness of controlling larvae and the influencing factors of lasers were studied to estimate optimal parameter combinations. Tests using the antifeedant effect and mortality of the larvae as dependent variables showed that the laser power, irradiation area, laser opening time and irradiation position were positively correlated with the P. rapae controlling effect. The optimal parameters for each factor were the following: laser power, 7.5 W; irradiation area, 6.189 mm2; laser opening time, 1.177 s; and irradiation position, middle of the abdomen. Based on these observations, a validation experiment was performed using the optimal combination of parameters, and the results showed that the antifeedant percentage of P. rapae larvae within 24 h posttreatment was 98.49%, whereas the mortality rate was 100%. The optimal parameter combination identified in the study was suitable for P. rapae larvae from the first- to fifth-instar stages, and a more effective controlling effect was observed with the younger larvae. These results can provide a theoretical basis for future pest control using laser pest-killing robots.

Electrosprayed mucoadhesive alginate-chitosan microcapsules for gastrointestinal delivery of probiotics

Besides viability protection, a sufficiently prolonged gastrointestinal retention of probiotics has emerged as critically important in improving the functional effectiveness of gastrointestinal delivery of these microorganisms. In this work, we formulated pure, resistant starch-reinforced and chitosan-coated alginate microparticles using an electrospray technique and evaluated their performance as mucoadhesive probiotic formulations for gastrointestinal delivery. In addition, we designed and successfully validated a novel experimental set-up of in vitro wash-off mucoadhesion test, using a portable and low-cost USB microscope for fluorescence imaging. In our test, pure chitosan microparticles (positive control) exhibited the greatest mucoadhesive property, whereas the alginate-resistant starch ones (negative control) were the least retentive on a gastric mucosa. These electrosprayed formulations were spherically shaped, with a size range of 30-600 µm (60-1300 µm with chitosan coating). Moreover, model probiotic Lactobacillus plantarum loaded in alginate-starch formulations was better protected against simulated gastric conditions than in alginate ones, but not better than in the chitosan-coated ones.

Sporopollenin Exine Microcapsules as Potential Intestinal Delivery System of Probiotics

Despite several decades of research into encapsulation of bacteria, most of the proposed technologies are in the form of immobilized cultures. In this work, sporopollenin exine capsules (SECs) opened, using silica particles which act as pressing micro-probes, and loaded with Lactobacillus casei (L. casei) cells, are described for the first time. The proposed encapsulation provided ≈30× higher encapsulation yield (30.87%), compared to direct compression of SECs (0.99%). Encapsulated L. casei cells show 1.21- and 2.25-folds higher viability compared to free cells, in in vitro simulated fasted and fed media representing the human gastrointestinal (GI) tract, respectively. Encapsulated L. casei can proliferate inside the SECs, generating enough pressure to cause the SECs to burst and release the viable and metabolically active cells. The noticeable difference with the application of the SECs as a means of encapsulation is that the SECs may act as a bioreactor and provide time for the encapsulated cells to multiply thousands of times before being released, following the SEC's burst. The unique advantages of SECs alongside the proposed encapsulation method, demonstrates the potential application of SECs as delivery system of probiotics to the distal part of the human GI tract.

Microencapsulation of Lactobacillus plantarum in W/O emulsions of okara oil and block-copolymers of poly(acrylic acid) and pluronic using microfluidic devices

Okara oil is a by-product remaining from defatting okara, the solid residue generated after extracting the aqueous fraction of grounded soybeans in the elaboration of soy beverages. The goal of this work was to encapsulate the probiotic Lactobacillus plantarum CIDCA 83114 into W/O emulsions composed of a block-copolymer constituted of pluronic® and acrylic acid (PPP12) and okara oil, prepared in microfluidic devices. For comparative purposes, alginate was also included as a second dispersed phase. Lactobacillus plantarum CIDCA 83114 was suspended in PPP12 or alginate giving rise to dispersed phases with different compositions, named I, II, III and IV. Controls were prepared by suspending microorganisms in water as dispersed phase. 6-carboxyfluorescein was added as bacterial marker in all the emulsions. The presence of green dyed bacteria in the dispersed phases, inside the droplets of the emulsions and the absence of fluorescence outside them, confirmed the complete encapsulation of bacteria in the dispersed phases. After being prepared, emulsions were freeze-dried. The exposure to gastric conditions did not lead to significant differences among the emulsions containing polymers. However, in all cases bacterial counts were significantly lower than those of the control. After exposing emulsions to the simulated intestinal environment, bacterial counts in assays I, II and III (emulsions composed of only one dispersed phase or of two dispersed phases with bacteria resuspended in the PPP12 one) were significantly greater than those of the control (p < 0.05) and no detectable microorganisms were observed for assay IV (emulsions composed of two dispersed phases with bacteria resuspended in the alginate one). In particular, bacterial cultivability in emulsions corresponding to assay I (only PPP12 as dispersed phase) exposed to the intestinal environment was 8.22 ± 0.02 log CFU/mL (2 log CFU higher than the values obtained after gastric digestion). These results support the role of PPP12 as an adequate co-polymer to protect probiotics from the gastric environment, enabling their release in the gut, with great potential for food or nutraceutical applications.

Soy Protein-Based Hydrogel under Microwave-Induced Grafting of Acrylic Acid and 4-(4-Hydroxyphenyl)butanoic Acid: A Potential Vehicle for Controlled Drug Delivery in Oral Cavity Bacterial Infections

The objective of this work was to evaluate grafted soy protein isolate (SPI) for pharmaceutical applications. The present work reports the microwave-assisted preparation of soy protein isolate\grafted[acrylic acid-co-4-(4-hydroxyphenyl)butanoic acid] [SPI-g-(AA-co-HPBA)] hydrogel via graft copolymerization using N,N-methylene-bis-acrylamide and potassium persulphate as the cross-linker and initiator, respectively. The chemical and physical properties of the synthesized polymeric hydrogels were analyzed by Fourier transform infrared spectroscopy, liquid chromatography-mass spectrometry (LCMS), nuclear magnetic resonance 1H-NMR, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The SEM, TEM, and XRD analyses have confirmed the formation of hydrogel SPI-g-(AA-co-HPBA) with the network structure having a layered and crystalline surface. The SPI-g-(AA-co-HPBA) hydrogel was investigated for the sustained and controlled drug delivery system for the release of model drug ciprofloxacin at basic pH for its utilization against bacterial infection in oral cavity. The drug release profile for SPI-g-(AA-co-HPBA) hydrogels was studied using LCMS at the ppb level at pH = 7.4. The synthesized hydrogel was found to be noncytotoxic, polycrystalline in nature with a network structure having good porosity, increased thermal stability, and pH-responsive behavior. The hydrogel has potential to be used as the vehicle for controlled drug delivery in oral cavity bacterial infections.

Recent trends in protein and peptide-based biomaterials for advanced drug delivery

Engineering protein and peptide-based materials for drug delivery applications has gained momentum due to their biochemical and biophysical properties over synthetic materials, including biocompatibility, ease of synthesis and purification, tunability, scalability, and lack of toxicity. These biomolecules have been used to develop a host of drug delivery platforms, such as peptide- and protein-drug conjugates, injectable particles, and drug depots to deliver small molecule drugs, therapeutic proteins, and nucleic acids. In this review, we discuss progress in engineering the architecture and biological functions of peptide-based biomaterials -naturally derived, chemically synthesized and recombinant- with a focus on the molecular features that modulate their structure-function relationships for drug delivery.

The Effect of the Ultra-High-Pressure Homogenization of Protein Encapsulants on the Survivability of Probiotic Cultures after Spray Drying

Interest in probiotic foods and ingredients is increasing as consumers become more aware of their potential health benefits. The production of these products often involves the use of dry culture powders, and the techniques used to produce such powders often suffer from significant losses of viable cells during drying or require the use of expensive drying technologies with limited throughput (e.g., freeze drying). In this study, the authors examined whether culture survivability during spray drying could be increased via the treatment of two common protein encapsulants with ultra-high-pressure homogenization (UHPH). Lactobacillus plantarum NRRL B-1927 (also known as ATCC 10241), a probiotic strain, was suspended in either soy protein isolate (SPI) or whey protein isolate (WPI) which had been either treated with UHPH at 150 Mpa or left untreated as a control. The suspensions were then dried using either concurrent-flow spray drying (CCSD), mixed-flow spray drying (MFSD) or freeze drying (FD) and evaluated for cell survivability, particle size, moisture content and water activity. In all cases, UHPH resulted in equal or greater survivability among spray dried cultures, showed reductions in particle size measures and, except for one marginal case (CCFD SPI), significantly reduced the moisture content of the dried powders. The combination of these findings strongly suggests that UHPH could allow probiotic powder manufacturers to replace freeze drying with spray drying while maintaining or increasing product quality.

Protein Polymer-Based Nanoparticles: Fabrication and Medical Applications

Nanoparticles are particles that range in size from about 1⁻1000 nanometers in diameter, about one thousand times smaller than the average cell in a human body. Their small size, flexible fabrication, and high surface-area-to-volume ratio make them ideal systems for drug delivery. Nanoparticles can be made from a variety of materials including metals, polysaccharides, and proteins. Biological protein-based nanoparticles such as silk, keratin, collagen, elastin, corn zein, and soy protein-based nanoparticles are advantageous in having biodegradability, bioavailability, and relatively low cost. Many protein nanoparticles are easy to process and can be modified to achieve desired specifications such as size, morphology, and weight. Protein nanoparticles are used in a variety of settings and are replacing many materials that are not biocompatible and have a negative impact on the environment. Here we attempt to review the literature pertaining to protein-based nanoparticles with a focus on their application in drug delivery and biomedical fields. Additional detail on governing nanoparticle parameters, specific protein nanoparticle applications, and fabrication methods are also provided.

Industrially-Scalable Microencapsulation of Plant Beneficial Bacteria in Dry Cross-Linked Alginate Matrix

Microencapsulation of plant-beneficial bacteria, such as pink pigmented facultative methylotrophs (PPFM), may greatly extend the shelf life of these Gram-negative microorganisms and facilitate their application to crops for sustainable agriculture. A species of PPFM designated Methylobacterium radiotolerans was microencapsulated in cross-linked alginate microcapsules (CLAMs) prepared by an innovative and industrially scalable process that achieves polymer cross-linking during spray-drying. PPFM survived the spray-drying microencapsulation process with no significant loss in viable population, and the initial population of PPFM in CLAMs exceeded 1010 CFU/g powder. The PPFM population in CLAMs gradually declined by 4 to 5 log CFU/g over one year of storage. The extent of alginate cross-linking, modulated by adjusting the calcium phosphate content in the spray-dryer feed, did not influence cell viability after spray-drying, viability over storage, or dry particle size. However, particle size measurements and light microscopy of aqueous CLAMs suggest that enhanced crosslinking may limit the release of encapsulated bacteria. This work demonstrates an industrially scalable method for producing alginate-based inoculants that may be suitable for on-seed or foliar spray applications.

Soy Protein Microparticles for Enhanced Oral Ibuprofen Delivery: Preparation, Characterization, and In Vitro Release Evaluation

The objective of this work was to evaluate soy protein isolate (SPI) and acylated soy protein (SPA) as spray-drying encapsulation carriers for oral pharmaceutical applications. SPI acylation was performed by the Schotten-Baumann reaction. SPA, with an acylation rate of 41%, displayed a decrease in solubility in acidic conditions, whereas its solubility was unaffected by basic conditions. The drug encapsulation capacities of both SPI and SPA were tested with ibuprofen (IBU) as a model poorly soluble drug. IBU-SPI and IBU-SPA particles were obtained by spray-drying under eco-friendly conditions. Yields of 70 to 87% and microencapsulation efficiencies exceeding 80% were attained for an IBU content of 20 to 40% w/w, confirming the excellent microencapsulation properties of SPI and the suitability of the chemical modification. The in vitro release kinetics of IBU were studied in simulated gastrointestinal conditions (pH 1.2 and pH 6.8, 37°C). pH-sensitive release patterns were observed, with an optimized low rate of release in simulated gastric fluid for SPA formulations, and a rapid and complete release in simulated intestinal fluid for both formulations, due to the optimal pattern of pH-dependent solubility for SPA and the molecular dispersion of IBU in soy protein. These results demonstrate that SPI and SPA are relevant for the development of pH-sensitive drug delivery systems for the oral route.

HPLC and UV-spectrophotometry analysis of flavonoids in spray-dried and freez-dried extracts of Teucrium polium L. (Lamiaceae)

Тhe aim of the study was identification and determination of the content of flavonoids in dry extracts of Teucrium polium, collected from Republic of Macedonia. Two different drying procedures were used, freeze and spray draying. In freeze-dried (FDE) and spray-dried (SDE) extracts of aerial parts of T. polium five flavone aglycones (luteolin, apigenin, cirsiliol, cirsimaritin and cirsilineol) were identified by HPLC method, on the base of retention times and UV spectral data of the components of the extracts in comparison to the authentic samples of flavonoids. Additionally, seven glycosides of apigenin and luteolin were tentatively identified. No significant differences in the composition nor in the content of identified flavonoids were found between both extracts. The content of total flavonoids determined by UV-spectrophotometry with AlCl3 was 72.8 ± 0.62 mg Lut/g and 73.34 ± 0.53 mg Lut/g in FDE and SDE extract of T. polium, respectively.