Simulated Gastrointestinal Conditions Research Articles

Co-encapsulation of vitamin D3 and Cordia myxa fruit peel extract in nanoemulsions

PurposeThis study investigated the production of free and encapsulated nanoemulsions using Cordia myxa fruit peel (CMFP) extract and vitamin D3.Design/methodology/approachThe CMFP extract was obtained using an ultrasonic technique, and its characteristics such as total phenolic content (TPC), antioxidant activity, cytotoxicity and gas chromatography-mass spectrometry (GC/MS) analysis were assessed. CMFP was encapsulated in vitamin D3 oil droplets of nanoemulsion prepared by ultra-homogenization using calcium alginate polymer. The nanoemulsions were evaluated for 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, antimicrobial activity, morphology, Fourier transform infrared (FTIR) analysis and release rate in a simulated gastrointestinal model.FindingsThe GC/MS results revealed that pyrocatechol, cholestanoids and propionaldehyde were the predominant compounds in the extract. The highest cytotoxicity effect of CMFP was observed at concentrations of 6.25 and 12.5 ppm of the extract. Encapsulated nanoemulsions exhibited the highest antimicrobial activity against Escherichia coli (ATCC 35218). The antioxidant activity of the free and encapsulated nanoemulsions ranged from 25.81 to 36.08 mg/100g and 49.25–55.7 mg/100g, respectively. Free nanoemulsions showed a higher release rate in the simulated gastric model compared to encapsulated ones. The FTIR spectrum allowed for the identification of functional groups responsible for antioxidant and antibacterial properties, indicating that these properties of the nanoemulsions were maintained.Originality/valueThis study demonstrates the successful co-encapsulation of CMFP extract and vitamin D3 in nanoemulsions, which significantly enhanced the stability, bioavailability and functional properties of both compounds. Encapsulated nanoemulsions exhibited higher antioxidant and antimicrobial activities compared to their free counterparts, with controlled release in simulated gastrointestinal conditions. These findings confirm that nanoemulsion-based encapsulation is an effective strategy to protect and enhance the bioactivity of plant extracts and vitamins, supporting their potential use in functional food products and therapeutic application.

Biochemical Characterization of Mannanase from Newly Isolated Acinetobacter sp. KUB-ST1-1 and its Hydrolysate Containing Mannooligosaccharides: Potential as Applied Prebiotic for Pet Food

The β-mannanase enzyme derived from isolated Acinetobacter sp. KUB-ST1-1 was studied for its potential for mannooligosaccharide production. Extracellular mannanase from Acinetobacter sp. KUB-ST1-1, cultured in nutrient broth with 0.5% (w/v) locust bean gum, was purified using ultrafiltration, anion exchange chromatography, and cation exchange chromatography. The enzyme, with a molecular weight of 57 kDa, had high activity in a 50 mM phosphate buffer at pH 6.0 and was stable from pH 4.0 to 7.0. It had high-temperature stability at 40 °C and 50 °C for up to 18 h. This enzyme was highly active toward konjac and galactomannan, especially with locust bean gum and copra meal. The hydrolysis products consisted mainly of the 2 and 3 units of mannooligosaccharide. The mannooligosaccharide exhibited prebiotic properties by promoting increased growth of some beneficial lactic acid bacteria. Furthermore, the defatted copra meal hydrolysate had considerable resistance to pepsin, trypsin, and bile salts under simulated gastrointestinal conditions for dogs. These characteristics highlighted the enzyme's excellent properties and suggested its potential as a promising candidate for applications in the food and bio-industries, particularly in pet food production.

Modeling the behavior of probiotic strains in foods under simulated gastrointestinal tract conditions

This study aimed to estimate the survival of two Weizmannia coagulans and a Lacticaseibacillus paracasei probiotic strain under simulated gastrointestinal conditions using different food matrices (a Brazilian processed cheese – “requeijão cremoso," orange juice, and homemade bread). The probiotic Weizmannia strains remained stable throughout digestion, showing good resistance to solutions of the gastrointestinal tract. Lacticaseibacillus paracasei PXN 37 showed inactivation kinetics with a good model fit (R2>0.90) at pH 1 in orange juice, cream cheese and when inoculated purely directly in the gastric solution, when the counts of this strain were < 6 log CFU/g in both foods studied. In the other pH conditions evaluated (pH 2-4), the reductions in the populations of the probiotic strains did not impair their viability at the end of gastric digestion, as counts were always >6 log CFU/g or mL. Orange juice and processed cheese could be considered as viable food matrices for the application of probiotics. The modeling approach employed herein highlights the potential of this approach to screen suitable strains for the best dose adjustment, to use different probiotic strains in food formulations, to identify the conditions that inhibit/delay their growth, and to ascertain the limiting factors for the shelf life of the probiotic products.

Starch-based encapsulation to enhance probiotic viability in simulated digestion conditions

This research aims to meet the demand for efficient delivery systems in the food, nutraceutical, and pharmaceutical industries. The study involved the synthesis of starch-based nanoparticles for potential application in the encapsulation of Lactobacillus rhamnosus. Various techniques such as zeta sizer, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to characterize the encapsulated probiotics in microbeads. The results showed 85.00 % encapsulation efficiency of beads. Microscopic analysis revealed that the probiotics accumulated within the wall material and formed small, smooth polygonal granules on the capsule surface. XRD analysis confirmed the presence of amorphous humps and some crystallinity of nanoparticles in the capsules. Moreover, encapsulation significantly improved probiotic viability under simulated gastrointestinal conditions. This study highlights the potential of starch-based nanoparticles to enhance the stability and viability of probiotics, demonstrating their potential applications across various industrial sectors. Further research should focus on investigating the long-term stability and functional efficacy of encapsulated probiotics in microbeads for real-world applications.

Characterization of two potential probiotic strains of Levilactobacillus brevis isolated from carp (Cyprinus carpio L.) with strong immunostimulatory activity on pikeperch (Sander lucioperca L.) head kidney cells

Aquaculture is inextricably linked to fish health problems, and the use of probiotic lactic acid bacteria (LAB) makes it possible to reduce losses caused mainly by bacterial pathogens. The aim of the present study was to isolate, characterize and select potential probiotic strains of lactic acid bacteria from the gut of common carp. We focused on obtaining strains that grow well under aerobic conditions to facilitate their future application through feed. After excluding strains with unwanted characteristics in vitro, two isolates of Levilactobacillus brevis were selected for this study. Despite belonging to the same species, the strains were biochemically different. However, both isolates met the in vitro selection criteria for potential probiotics. The tested L. brevis strains showed antagonistic activity against pathogenic bacteria isolated from carp and rainbow trout (Aeromonas hydrophila, Aeromonas salmonicida, Pseudomonas fluorescens, and Acinetobacter junii) and demonstrated co-aggregation ability with pathogens. Both strains tolerated stress well under simulated gastrointestinal tract conditions (i.e., showed acid and bile tolerance) and exhibited auto-aggregation capacity. The tested isolates were nonhemolytic, gelatinase negative and susceptible to most of the antibiotics tested. The cell-free supernatants of both L. brevis isolates exhibited strong immunostimulatory effects on pikeperch head kidney immune cells and immunomodulatory effects on carp immune cells. The results of in vitro tests encourage further research into the probiotic potential of these strains under in vivo conditions.

Isolation of yeast from some Ethiopian traditional fermented beverages and in vitro evaluation for probiotic traits

Traditional fermented foods and beverages are important sources of probiotic microbes. The purpose of this study was to isolate yeast from Ethiopian fermented beverages and assess their probiotic activity in an in vitro setting. Yeast isolation, identification, and in vitro probiotic trait screening were conducted in accordance with established protocols. Eleven isolates were obtained. Of them, GB1D5, RTj3D3 and DMTD2 were low hydrogen sulfide producers and were selected. The D1/2 genotyping of selected isolates revealed that they were strains of Saccharomyces cerevisiae. All strains grew well at low pH, body temperature, bile salt concentrations (0.3–0.6 (w/v)) and survived at simulated gastrointestinal conditions with survival percentages of 12.8 ± 4.9 to 14.4 ± 5.0 % and 5.3 ± 1.7–5.9 ± 1.8 %, respectively. They demonstrated surface hydrophobicity ranging from 61.3 to 68.7 %; and 80.7–86 % auto-aggregation percentages after 24 h of incubation. They also showed hydroxyl radical scavenging activity ranging between 91.6 and 92.3 % and mild inhibitory activity against Escherichia coli (ATCC 893614) and Staphylococcus aureus (ATCC 892760). The PCA revealed that two strains (DMTD2 and RTj3D3) have a strong association with most probiotic properties, which affirms their promising candidacy. Safety assessments indicated that they were resistant to antibacterial antibiotics, susceptible to antifungals, and negative for protease, gelatinase, biogenic amine production, and hemolytic activity. All these suggest that they are promising candidates for the production of food containing probiotics. Examining their performance in vivo circumstances is recommended.

Chemical, microbial, and functional characterization of a new fruity probiotic kombucha

This study aimed to evaluate the effect of adding Lacticaseibacillus casei as probiotic culture and/or camu-camu (Myrciaria dubia) pulp on the chemical profile, technological, functional, and sensory properties, phenolics concentration and bioaccessibility, and microbiota of kombucha. Adding L. casei decreased some volatile compounds and fruity flavor intensity and increased the Lactobacillus relative abundance (+35.73 %) and lactic acid content (from 1.26 to 1.54 g/L), decreasing flavor and overall impression acceptances. Adding camu-camu pulp resulted in more acidic products (pH of 2.75 vs 3.24), with a higher concentration of some phenolic compounds. The kombucha with L. casei and camu-camu pulp was characterized by a higher concentration of citric and acetic acids, ethanol, ascorbic acid, and most of the phenolic compounds and volatile compounds, higher bioaccessibility of phenolic compounds, increased consistency index, improved functional properties (inhibition of α-glucosidase and antioxidant activity), and better sensory properties. Furthermore, it showed an increased relative abundance of Lactobacillus (+15.11 %) and a decreased relative abundance of Acetobacter (−5.56 %) and Komagataeibacter (−9.12 %) compared to the conventional kombucha. L. casei survived the processing (> 7 log CFU/mL) and simulated gastrointestinal conditions (>5 log CFU/mL). In conclusion, the association of L. casei and camu-camu pulp resulted in potentially probiotic kombuchas with improved chemical profile, functional, technological, and sensory properties, phenolic compounds concentration and bioaccessibility, and bacterial microbial diversity.

In Vitro Cholesterol Uptake by the Microflora of Selected Kefir Starter Cultures.

Kefir, a fermented milk beverage, is recognized for its potential health benefits, including its cholesterol-lowering properties. This study demonstrated that selected kefir starter cultures, including Lactococcus strains and yeasts, significantly reduce cholesterol-binding capacity under simulated gastrointestinal conditions, underscoring the challenges of probiotic delivery. We compared the performance of these cultures under laboratory conditions (growth broths) and simulated digestive juice models. Lactococcus strains showed significant differences in cholesterol binding between the two environments, highlighting the limitations of relying solely on laboratory testing. Yeast cultures also exhibited greater cholesterol binding in their native broths, but their survival was limited in digestive models. Our findings suggest that effective probiotic formulations should prioritize strains with high cholesterol-binding capacity and robust survival rates throughout the digestive tract. This study provides valuable insights for future research on the mechanisms behind these functionalities and the potential of kefir yeast strains for use in human digestive models. Our results can be used to inform the development of improved probiotic formulations for cholesterol management.

Targeted Screening of Lactiplantibacillus plantarum Strains Isolated from Tomatoes and Its Application in Tomato Fermented Juice.

This study explores the functional attributes of Lactiplantibacillus plantarum (L. plantarum) strains isolated from fermented tomato juice, focusing on their physiological, biochemical, and probiotic characteristics. The identified 66 gram-positive strains included 36 L. plantarum ones, which exhibited robust growth in acidic environments (pH 2.0-5.0) and utilization of various carbohydrates. Notably, seven strains outperformed a commercial strain in extreme acidic conditions. Antioxidant activity varied, with strain A24 showing the highest hydroxyl radical scavenging ability, while strains with high surface hydrophobicity had lower DPPH scavenging activity, indicating no direct correlation between these properties. Strains also showed strain-specific differences in carbohydrate utilization and antibiotic resistance, with some resistant to gentamicin and ciprofloxacin. Survival rates under simulated gastrointestinal conditions were strain-specific, with some strains demonstrating high survival rates, indicating their potential as probiotics. Furthermore, 13 strains used as fermentation starters in tomato juice significantly enhanced antioxidant activity and reduced pH and total soluble solids, indicating efficient sugar utilization and lactic acid production. These findings suggest that L. plantarum strains are well-suited for functional food fermentation and probiotic applications, with strain-specific traits offering versatility for use in acidic food products and probiotic formulations.

Comprehensive genomic analysis and evaluation of in vivo and in vitro safety of Heyndrickxia coagulans BC99

This study aimed to evaluate the safety profile and beneficial effects of Heyndrickxia coagulans strain BC99 (BC99) for potential use in functional foods and pharmaceuticals. We began with whole genome sequencing of BC99, followed by a comprehensive safety assessment comprising genome analysis, hemolysis, cytotoxicity, antibiotic susceptibility tests, and cell adhesion and tolerance studies, along with acute and subacute oral toxicity studies in animal models. BC99 was isolated from a well-characterized collection originating from the feces of a healthy infant. Our results indicated no hemolytic activity on Columbia blood agar plates and broad antibiotic sensitivity, including to gentamicin, ampicillin, chloramphenicol, ciprofloxacin, and others. Cytotoxicity testing confirmed no adverse effects on HT-29 cells and significant adhesive properties to intestinal epithelial cells. Tolerance tests demonstrated over 90% viability of BC99 under simulated gastrointestinal conditions. In vivo studies in mice and rats confirmed the absence of adverse effects following oral administration. Collectively, these findings support BC99’s robust tolerance to gastrointestinal environments, strong adhesion capabilities, and a broad spectrum of antibiotic resistance, underlining its potential as a safe and effective agent for gut microbiota modulation and host health enhancement.

Stability and release kinetics of nanoliposomes containing bitter melon fruit extract at different temperatures and pH values, and in simulated gastrointestinal conditions

In this study, the nanoliposomes loaded with bitter melon extract were synthesized at different concentrations of lecithin (1, 3, and 5 g/100 g) and extract (0.5 and 1 g/100 g). Thermal properties of nanoliposomes and their stability at various pH values and temperatures, as well as under simulated gastrointestinal conditions, were assessed. The results showed that an increase in the concentration of lecithin and extract elevated the melting temperature of the nanoliposomes. The release of the extract increased at high temperatures, and it was more pronounced at pH = 3 than the other pH values. Also, the release followed a continuous and gradual trend under the simulated gastrointestinal conditions, slower in gastric conditions than in intestinal. Additionally, it was reduced at higher concentrations of lecithin and extract in simulated gastrointestinal conditions. The release kinetics of the extract followed different models based on temperature and pH. In conclusion, nanoliposomes were suitable and highly stable carriers for the bitter melon extract encapsulation. Moreover, the controlled release of the extract from the nanoliposomes could be properly evaluated in model systems and foodstuffs using empirical models.

Co-encapsulation of probiotic bacteria and fructooligosaccharides in basil seed gum-stabilized double emulsion gels: Probiotic viability and physicochemical properties

Double emulsions (DEs) present many potential applications for encapsulating and protecting probiotics. However, their high instability limit their real applications. To improve the prolonged stability of DEs, Lacticaseibacillus rhamnosus and Lactobacillus gasseri were separately co-encapsulated together in the presence of fructooligosaccharides (FOSs) and basil seed gum (BSG) within the internal (W1) and external (W2) aqueous phases of double emulsion gels (DEGs; W1-sol/O/W2-gel). Physical properties of DEGs, and viability of probiotics during heat processing, gastrointestinal digestion and storage were evaluated. Appropriate physical stability was observed during storage for 28 d at 4 ± 2 °C. The FOSs and microorganism type showed not effect on the droplet size (10.63 to 10.47 µm). Turbidimetry, physical stability, and morphological studies revealed the formation of aggregated droplets after 3 weeks. All DEGs presented high (>90 %) encapsulation efficiency. The viability of microencapsulated probiotics over time (14.89–14.08 %) and against simulated gastrointestinal conditions was higher than that of free cells. The encapsulation of bacteria in W1 in the presence of FOSs led to a significant improvement of viability against heat (only 1.35 % to 6.83 % reduction at 72 °C). L. gasseri showed a higher stability against environmental conditions. Finally, BSG-stabilized DEGs can be considered for increasing the viability of probiotic in functional foods.

Probiotic Bacteria as a Green Solution for Mitigating Zearalenone Toxicity and Pollution

Distiller-dried grains with solubles (DDGS) are a valuable feed protein but are often contaminated with zearalenone (ZEN), a toxic mycotoxin affecting animal reproduction. This study investigates L-25 for ZEN removal from DDGS. Among 12 screened lactic acid bacteria, strain L-25 showed the highest removal rate of 45.5% for 10 mg/L ZEN within 24 h. Strain L-25, a Gram-positive, rod-shaped bacterium, was identified as Lactobacillus reuteri (PQ578323) through 16S rDNA analysis. The strain was tested for growth and ZEN tolerance, showing a 53.2% removal rate at 37°C and pH 7.0 with a cell concentration of 1×109 CFU/mL. Mechanistic studies revealed ZEN removal involves both bio-adsorption (44.4% from cell walls) and bio-transformation (16% from supernatant). FT-IR identified bio-adsorption sites as peptidoglycan in the cell wall, with a hydrophobic mechanism, while mass spectrometry confirmed no estrogen-active byproducts. Under optimal conditions (5% inoculation, 1:0.7 ratio, 37°C, 72 h), L-25 achieved a 53.70% ZEN removal rate in DDGS. In simulated gastrointestinal conditions, ZEN removal rates were 30.28% and 36.05%, demonstrating its effectiveness in a gastrointestinal environment. This study highlights the potential of L-25 for effectively removing ZEN from DDGS, offering a viable solution for improving feed safety. Its findings could drive advancements in mycotoxin management and enhance the quality of animal feed.

Isolation and characterization of Bifidobacterium spp. From breast milk with different human milk oligosaccharides utilization and anti-inflammatory capacity

Breast milk is the best source of nutrition for infants. Human milk oligosaccharides (HMOs) and the corresponding HMOs-consuming Bifidobacterium positively influence infant health. This study aims to isolate and characterize Bifidobacterium from breast milk of healthy Chinese mothers, identifying the most efficacious strains for inclusion in simulated maternal milk formulas. Nine Bifidobacterium strains (two of B. breve and seven of B. infantis) were isolated, exhibiting a broad spectrum of probiotic potential. This included tolerance to simulated infant gastrointestinal conditions, notable adhesion, antibacterial, antioxidant activities, and HMOs utilization ability. Lacto-N-Tetraose (LNT) is preferred in early growth among Bifidobacterium isolates. B. breve showed a preference for LNT, whereas B. infantis showed a preference for fucosylated HMOs, and displayed reduced utilization of sialylated HMOs. They also exhibited robust safety profiles, including no hemolytic activity, an appropriate D/L lactate-producing ratio, and non-toxicity in an acute oral toxicity assay on mice. It is noteworthy that B. breve N-90, O-147, B. infantis O-161 and R-1 exhibited anti-inflammatory effects in LPS-induced RAW 264.7 cells. Specifically, a notable reduction in TNF-α levels was observed in pre-treatment, while a decrease in IL-1β and IL-6 levels in co-treatment. B. breve N-90 and B. infantis R-1 were identified finally as promising probiotic candidates. Their whole-genome sequencing analysis confirmed presence of functional genes associated with gastrointestinal colonization, antioxidation, and glycoside hydrolase activity on HMOs. The annotation for antibiotic resistance and virulence genes concurred with phenotypes, further validating the safety. Breast milk is a good source for Bifidobacteria isolation, while Bifidobacteria utilize HMOs in a strain-dependent manner. The two selected strains, B. breve N-90 and B. infantis R-1, are potential candidates for inclusion in simulated maternal milk formulas and deserved further in vivo investigation for their health-promoting effects.

Isolation and Characterization of a Bacteriophage with Potential for the Control of Multidrug-Resistant Salmonella Strains Encoding Virulence Factors Associated with the Promotion of Precancerous Lesions.

Antimicrobial-resistant bacteria represent a serious threat to public health. Among these bacteria, Salmonella is of high priority because of its morbidity levels and its ability to induce different types of cancer. This study aimed to identify Salmonella strains encoding genes linked to the promotion of precancerous lesions and to isolate a bacteriophage to evaluate its preclinical potential against these bacteria. An epidemiological approach based on wastewater analysis was employed to isolate Salmonella strains and detect genes associated with the induction of precancerous lesions. Antimicrobial susceptibility was assessed by the disk diffusion method. A bacteriophage was isolated via the double agar technique, and its morphological characteristics, stability, host range, replication dynamics, and ability to control Salmonella under different conditions were evaluated. The bacteriophage genome was sequenced and analyzed using bioinformatics tools. Thirty-seven Salmonella strains were isolated, seventeen of which contained the five genes associated with precancerous lesions' induction. These strains exhibited resistance to multiple antimicrobials, including fluoroquinolones. A bacteriophage from the Autographiviridae family with lytic activity against 21 bacterial strains was isolated. This phage exhibited a 20 min replication cycle, releasing 52 ± 3 virions per infected cell. It demonstrated stability and efficacy in reducing the Salmonella concentration in simulated gastrointestinal conditions, and its genome lacked genes that represent a biosafety risk. This bacteriophage shows promising preclinical potential as a biotherapeutic agent against Salmonella.

In vitro validation of colon delivery of vitamin B2 through a food grade multi-unit particle system.

Colon target delivery of active ingredients is frequently applied in pharmaceutical products. However, in functional food and beverage applications, dietary supplements, and medical nutrition, formats targeting colonic delivery to improve human health are rare. Nevertheless, there is emerging evidence for beneficial effects of colonic delivered nutrients on gut microbiota and host health which increases the demand for sustainable food grade materials that are regulatory approved for application. In this paper, we describe a double layer coated multi-unit particle system (MUPS) with a diameter of approximately 730 microns consisting of food grade materials: shellac as outer layer, alginate as inner layer, cellulose as a core and riboflavin as active ingredient. The suitability of the MUPS for colonic delivery was tested in three well-established in vitro digestion and fermentation models: the USP Apparatus 3 and the TNO Intestinal Models 1 and 2 (TIM-1 and TIM-2). All systems confirmed the integrity of the MUPS under simulated upper gastrointestinal tract conditions with approximately 90% of the active ingredient being released under simulated ileal-colonic conditions. The TIM-2 model also showed the effects of riboflavin loaded MUPS on the microbiome composition with an increase in the production of short-chain fatty acids, acetate and butyrate. The results of these experiments provide a reliable basis for validation of this vitamin-loaded food grade MUPS in future human clinical trials. In addition, following the recent announcement of the European Commission to restrict intentionally added microplastics to products, the materials used in the described formulation offer an environmentally friendly alternative to often applied methyl acrylate based coatings.

Genomic Characterization and Probiotic Properties of Lactiplantibacillus pentosus Isolated from Fermented Rice.

The aim of the study was the preliminary genetic and phenotypic characterization of a potential probiotic strain of Lactiplantibacillus pentosus (strain krglsrbmofpi2) obtained from traditionally fermented rice. Genome sequencing revealed that the strain has a 3.7-Mb genome with a GC content of 46 and a total of 3192 protein-coding sequences. Using bioinformatic methods, we have successfully identified phage genes, plasmids, pathogenicity, antibiotic resistance and a variety of bacteriocins. Through comprehensive biochemical and biophysical analyses, we have gained valuable insights into its auto-aggregation, co-aggregation, antibiotic resistance, hydrophobicity, antioxidant activity and tolerance to simulated gastrointestinal conditions. The safety evaluation of the isolated L. pentosus was performed on the basis of its haemolytic activity. Our studies have shown that this strain has a strong antagonistic activity against the priority pathogens identified by the World Health Organization such as Vibrio cholerae, Clostridium perfringens, Salmonella enterica subsp. enterica ser. Typhi, Escherichia coli, Listeria monocytogenes and Staphylococcus aureus. It is essential to fully understand the genetic and functional properties of the L. pentosus strain before considering its use as a useful probiotic in the food industry.

Preparation, characterization, and stability of chitosan-tremella polysaccharide layer-by-layer encapsulated astaxanthin nanoemulsion delivery system

In this study, a layer-by-layer (LBL) encapsulated astaxanthin (Ast) nanoemulsion delivery system based on chitosan (CS) and tremella polysaccharide (TP) was successfully developed. The system constructed an Ast-CS-TP emulsion with high encapsulation efficiency and an excellent stability profile by utilizing the opposite charge properties of CS and TP. This study evaluated the effects of different stresses (including temperature, salt addition, pH, UV irradiation, and centrifugal force) on the emulsion's stability. To further investigate the protective mechanism of the emulsions, we performed antioxidant activity experiments after UV treatment. Additionally, an in vitro digestion experiment was conducted to assess the behavior of Ast emulsion under simulated gastrointestinal conditions. The stability correlation coefficients were calculated using the Python database Pandas. The results showed that Ast-CS-TP emulsions exhibited turbidity and enhanced homogeneity with a small particle size of around 400 nm and a high absolute zeta potential of 35 mV and exhibited excellent stability under various stresses. The Ast-CS-TP emulsions also exhibited pH-responsive release at pH ≥ 7, consistent with pH changes in the gastrointestinal tract, and were stable in highly concentrated salt solutions. We found that the CS and TP layers significantly improved the photostability of Ast. CS and TP significantly enhanced Ast's oral bioavailability. The stability correlation coeffcients showed that pH and salt concentration were the largest factors that affected the stability of the emulsion. This study provided important insights into the encapsulation and targeting of Ast, providing a theoretical foundation and technical guidance for the comprehensive utilization of Ast.

Encapsulation of EGCG by whey protein isolate and β-cyclodextrin nanocomplexes: A strategy to mask the bitter and astringent taste and increase the stability in beverages

(−)-Epigallocatechin-3-gallate (EGCG) is the main active component of tea polyphenols, which endows tea with bitter and astringent taste and is susceptible to degradation in presence of light, heat and oxygen. In this study, whey protein isolate (WPI) and β-cyclodextrin (β-CD) were used to prepare the WPI-β-CD nanocomplexes for masking the bitter taste and protecting EGCG. The encapsulation efficiency of EGCG by WPI-β-CD nanocomplexes reached to 79.61%. Sensory evaluation indicated that the bitter and astringent taste of EGCG was masked. FTIR results suggested that the WPI/β-CD-EGCG nanocomplexes were formed through electrostatic, hydrogen bonding and hydrophobic interactions among WPI, β-CD and EGCG. The molecular mechanism of taste masking was preliminarily investigated by molecular docking, suggesting that the bitter and astringent taste moiety of EGCG was inserted into the hydrophobic cavity of β-CD, thereby masking the bitter and astringent taste of EGCG. The results of in vitro gastrointestinal experiments and scanning electron microscopy indicated that the WPI-β-CD nanocomplexes effectively encapsulated EGCG and achieved sustained release in simulated gastrointestinal conditions, thus showing potential application prospects in tea beverages and related areas.

Symbiotic sheep milk cheese containing Moringa oleifera extract and Bifidobacterium pseudolongum INIA P2

Healthy non-bovine functional dairy products are reaching high interest among consumers. In the present study, an aqueous polyphenol-rich Moringa oleifera extract (MoE) and a Bifidobacterium strain of human origin (B. pseudolongum INIA P2) were added, alone or in combination, for the manufacture of three experimental and one control sheep milk cheeses. In general, addition of 2.05 g of lyophilized MoE per 100 g of curd did not affect cheese dry matter or lactococci starter counts during ripening. B. pseudolongum INIA P2 showed good viability in cheese during ripening, and after simulated major gastrointestinal conditions, reaching levels above 7 log CFU / g of cheese. Cheeses with MoE showed lower pH, higher proteolysis and aminopeptidase activity than control cheese. MoE impoved functional properties, significantly (P < 0.01) increasing total phenolic content (TPC) and, especially, antioxidant capacity, with respect to control cheese. MoE modified cheese colour and volatile profile. Cheeses with MoE were darker in colour with higher red and yellow components than control cheese. Several volatile compounds were only detected in cheeses with MoE, indicating their plant origin. On top of that, increased levels of compounds originating from amino acid catabolism were present in these cheeses, as a result of their higher proteolytic and peptidolytic indexes. The symbiotic cheese with MoE and B. pseudolongum INIA P2 could confer beneficial effects on consumers' health by increasing polyphenol bioavailability and contributing to the host antioxidant capacity.