Encapsulation of Lactobacillus reuteri in W1/O/W2 double emulsions: Formulation, storage and in vitro gastro-intestinal digestion stability

Lactobacillus reuteri biofilms formed on porous zein/cellulose scaffolds: Synbiotics to regulate intestinal microbiota

Supplementing probiotics or indigestible carbohydrates is a usual strategy to prevent or revert unhealthy states of the gut by reshaping gut microbiota. One criterion that probiotics are efficacious is the capacity to survive in the gastrointestinal tract. Biofilm is the common growth mode of microorganisms with high tolerances toward harsh environments. Suitable scaffolds are crucial for successful biofilm culture and large-scale production of biofilm-phenotype probiotics. However, the role of scaffolds containing indigestible carbohydrates in biofilm formation has not been studied. In this study, porous zein/cellulose composite scaffolds provided nitrogen sources and carbon sources simultaneously at the solid/liquid interfaces, being beneficial to the biofilm formation of Lactobacillus reuteri. The biofilms showed 2.1-17.4 times higher tolerances in different gastrointestinal conditions. In human fecal fermentation, the biofilms combined with the zein/cellulose composite scaffolds act as the "synbiotics" positively modulating the gut microbiota and the short-chain fatty acids (SCFAs), where biofilms provide probiotics and scaffolds provide prebiotics. The "synbiotics" show a more positive regulation ability than planktonic L. reuteri, presenting potential applications in gut health interventions. These results provide an understanding of the synergistic effects of biofilm-phenotype probiotics and indigestible carbohydrates contained in the "synbiotics" in gut microbiota modulation.

An Updated Comprehensive Overview of Different Food Applications of W1/O/W2 and O1/W/O2 Double Emulsions

Double emulsions (DEs) present promising applications as alternatives to conventional emulsions in the pharmaceutical, cosmetic, and food industries. However, most review articles have focused on the formulation, preparation approaches, physical stability, and release profile of encapsulants based on DEs, particularly water-in-oil-in-water (W1/O/W2), with less attention paid to specific food applications. Therefore, this review offers updated detailed research advances in potential food applications of both W1/O/W2 and oil-in-water-in-oil (O1/W/O2) DEs over the past decade. To this end, various food-relevant applications of DEs in the fortification; preservation (antioxidant and antimicrobial targets); encapsulation of enzymes; delivery and protection of probiotics; color stability; the masking of unpleasant tastes and odors; the development of healthy foods with low levels of fat, sugar, and salt; and design of novel edible packaging are discussed and their functional properties and release characteristics during storage and digestion are highlighted.

Influence of different electrolytes and oils on the stability of W1/O/W2 double emulsion during storage and in vitro digestion

The aim of this study is to formulate a stable water-in-oil-in-water (W1/O/W2) double emulsion using different types of oils and electrolytes. W1/O was formulated with different electrolyte solutions (W1) dispersed in various oils (O) using polyglycerol polyricinoleate as a stabilizer. External aqueous phase was Tween-80 (W2), and W1/O dispersed in W2 was used. The emulsion containing NaCl or MgCl2 exhibited high encapsulation efficiency (EE) and maintained particle size. Regarding the oil type, the emulsion with MCT oil showed a small droplet size and a high viscosity and EE, presenting a stable droplet distribution in optical observation. The stability of emulsion containing NaCl was maintained during the in vitro digestion experiments. MCT oil, NaCl and MgCl2 have the potential to produce stable double emulsions for storage stability and in vitro digestion studies. The findings would be useful for preparing stable double emulsions used in the food and cosmetic industries.

Progress in the Application of Food-Grade Emulsions

The detailed investigation of food-grade emulsions, which possess considerable structural and functional advantages, remains ongoing to enhance our understanding of these dispersion systems and to expand their application scope. This work reviews the applications of food-grade emulsions on the dispersed phase, interface structure, and macroscopic scales; further, it discusses the corresponding factors of influence, the selection and design of food dispersion systems, and the expansion of their application scope. Specifically, applications on the dispersed-phase scale mainly include delivery by soft matter carriers and auxiliary extraction/separation, while applications on the scale of the interface structure involve biphasic systems for enzymatic catalysis and systems that can influence substance digestion/absorption, washing, and disinfection. Future research on these scales should therefore focus on surface-active substances, real interface structure compositions, and the design of interface layers with antioxidant properties. By contrast, applications on the macroscopic scale mainly include the design of soft materials for structured food, in addition to various material applications and other emerging uses. In this case, future research should focus on the interactions between emulsion systems and food ingredients, the effects of food process engineering, safety, nutrition, and metabolism. Considering the ongoing research in this field, we believe that this review will be useful for researchers aiming to explore the applications of food-grade emulsions.

Designated functional microcapsules loaded with green synthesis selenium nanorods and probiotics for enhancing stirred yogurt

Green synthesis selenium nanorods (Se-NRs) were produced based on Aloe vera leaf extract. The size, morphology, antimicrobial, and activation of Se-NRs for probiotics were analyzed. The Se-NRS was stable with a diameter of 12 and 40 nm, had an antimicrobial effect, and improved probiotics counts. The microcapsules loaded with Green Se-NRS (0, 0.05 or 0.1 mg/100 ml) and probiotics (Bifidobacterium lactis and Lactobacillus rhamnosus) were designated with efficiency between 95.25 and 97.27% and irregular shapes. Microcapsules were saved probiotics against gastrointestinal juices. The microcapsules were showed a minor inhibition effect against the cell line. Also, microcapsules integrated into stirred yogurt and exanimated for microbiology, chemically, and sensory for 30 days. The probiotics counts, acidity, total solids, and ash values of samples were increased during storage periods without affecting fat and protein contents. The overall acceptability of yogurt with microcapsules containing probiotics and Se-NRs was high without change in body, odor, color, and appearance.

Biopolymer-Based Multilayer Microparticles for Probiotic Delivery to Colon

The potential health benefits of probiotics may not be realized because of the substantial reduction in their viability during food storage and gastrointestinal transit. Microencapsulation has been successfully utilized to improve the resistance of probiotics to critical conditions. Owing to the unique properties of biopolymers, they have been prevalently used for microencapsulation of probiotics. However, majority of microencapsulated products only contain a single layer of protection around probiotics, which is likely to be inferior to more sophisticated approaches. This review discusses emerging methods for the multilayer encapsulation of probiotic using biopolymers. Correlations are drawn between fabrication techniques and the resultant microparticle properties. Subsequently, multilayer microparticles are categorized based on their layer designs. Recent reports of specific biopolymeric formulations are examined regarding their physical and biological properties. In particular, animal models of gastrointestinal transit and disease are highlighted, with respect to trials of multilayer microencapsulated probiotics. To conclude, novel materials and approaches for fabrication of multilayer structures are highlighted.

Stirred Yogurt as a Delivery Matrix for Freeze-Dried Microcapsules of Synbiotic EVOO Nanoemulsion and Nanocomposite

Nowadays, dairy products are considered a good matrix to deliver many functional substances either vital oils or probiotic cells. Two models of microcapsules were produced from co-encapsulation of extra virgin olive oil (EVOO) nanoemulsion or nanocomposite and synbiotic bacteria (maltodextrin with Lactobacillus acidophilus and Bifidobacterium bifidum) using the freeze-drying technique. These models of microcapsules were added to stirred yogurt, and then its storage effect on microbiology, chemically, and sensory properties were evaluated for 21 days. The average droplet size and zeta potential distribution of EVOO nanoemulsion and nanocomposite were investigated. Also, oxidative stability, microencapsulation efficiency, release profile, and antioxidant activity were studied. The results showed that the average particle size of EVOO nanoemulsion and nanocomposite ranged between 416 and 475 nm, while zeta potential was -39.6 and -33.6 mV, respectively. The induction period of EVOO extracted from nanoemulsion and nanocomposite microcapsules models was 11.30 and 8 h. The microencapsulation efficiency of probiotic and EVOO was determined at 88.84 and 65.61% for the nanoemulsion microcapsules model, while the nanocomposite microcapsules model showed 98.49 and 72%. The two models of microcapsules have boosted the viability of probiotic bacteria inside stirred yogurt than free cells. Also, the presence of microcapsules did not affect the viability of stirred yogurt starter cultures, and high values for the total solid and protein were detected. Therefore, the results recommended that stirred yogurt is a good delivery carrier for highly antioxidant and healthy microcapsules of synbiotic EVOO nanoemulsion and nanocomposite.

Poloxamer 407-Based Thermosensitive Emulgel as a Novel Formulation Providing a Controlled Release of Oil-Soluble Pharmaceuticals-Ibuprofen Case Study

This article covers the design and evaluation of a novel drug vehicle: a thermosensitive, injectable, high-oil-content (50% w/w) emulgel providing a controlled release of lipophilic pharmaceuticals. Different vegetable (castor, canola, olive, peanut, grapeseed, linseed), mineral (paraffin) and semisynthetic (isopropyl myristate, oleic acid) oils were screened for ibuprofen (IBU) solubility and for their capacity for high-shear emulsification in a 17% (w/w) aqueous solution of poloxamer 407. Chosen emulgels were subject to a rheological evaluation, a syringeability test (TA.XT texture analyser; 2 mL syringe; 18 G, 20 G and 22 G needles) and a drug release study (48 h; cellulose membrane; 0.05 mol/L phosphate buffer at pH 7.4). Castor oil turned out to be an optimal component for IBU incorporation. Blank and drug-loaded castor oil emulgels were susceptible to administration via a syringe and needle, with the absolute injection force not exceeding 3 kg (29.4 N). The drug release test revealed dose-dependent, quasi-linear kinetics, with up to 44 h of controlled, steady, linear release. The results indicate the significant potential of high-oil-content, oil-in-water thermosensitive emulgel formulations as vehicles for the controlled release of lipophilic APIs.