Simulated Gastrointestinal Tract Model Research Articles

The Effect of Multilayer Nanoemulsion on the In Vitro Digestion and Antioxidant Activity of β-Carotene.

The objectives of this study were to design multilayer oil-in-water nanoemulsions using a layer-by-layer technique to enhance the stability of β-carotene and evaluate its effect on in vitro release and antioxidant activity. To prepare β-carotene-loaded multilayer nanoemulsions (NEs), a primary NE (PRI-NE) using Tween 20 was coated with chitosan (CS) for the secondary NE (SEC-CS), and with dextran sulfate (DS) and sodium alginate (SA) for the two types of tertiary NEs (TER-DS, TER-SA). The multilayer NEs ranged in particle size from 92 to 110 nm and exhibited high entrapment efficiency (92-99%). After incubation in a simulated gastrointestinal tract model, the release rate of free fatty acids decreased slightly after coating with CS, DS, and SA. The bioaccessibility of β-carotene was 7.02% for the PRI-NE, 7.96% for the SEC-CS, 10.88% for the TER-DS, and 10.25% for the TER-SA. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging abilities increased by 1.2 times for the multilayer NEs compared to the PRI-NE. In addition, the cellular antioxidant abilities improved by 1.8 times for the TER-DS (87.24%) compared to the PRI-NE (48.36%). Therefore, multilayer nanoemulsions are potentially valuable techniques to improve the stability, in vitro digestion, and antioxidant activity of β-carotene.

Characterization of probiotic strains of Bacillus sp. from fermented palm wine (Nypa fructicans sp.) and exploration of cellulolytic potential for use as an addition in animal feed.

The main objective of this study was to assess cellulolytic probiotic strains from traditional fermented beverages such as palm wine in order to supplement the animal feed and strengthen the gut health of the animal for better digestibility and absorption. In the present study, different types of microbes were isolated from traditionally prepared palm wine and analyzed for their probiotic nature. For any microbe to be probiotic in nature, it has to sustain the harsh conditions of the human gastrointestinal tract such as acid tolerance, bile tolerance at the lower range of pH, and other properties like auto aggregation test, cell surface hydrophobicity test with non-polar hydrocarbons for evaluating its capabilities to adhere to the intestinal cells and antimicrobial nature against pathogens. Bacillus mycoides strain PR04 and Bacillus subtilis strain PR21 were found to be resistant to acid and bile in simulated artificial gastrointestinal tract model, found to be than 55% hydrophobic with xylene and n-hexadecane and also showed antimicrobial activity greater towards pathogenic strains like Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, and Salmonella typhimurium respectively. The cellulolytic activity of the isolates PR04 and PR21 was evaluated in (0.2-2) % CMC (carboxymethyl cellulose) plate. Bacillus mycoides PR04 and Bacillus subtilis PR21 could degrade carboxymethyl cellulose, filter paper, and sugarcane bagasse. The degradation of sugarcane bagasse was confirmed by Scanning electron microscopy and filter paper degradation after 4days of incubation at 37°C. Cellulase gene of the identified Bacillus sp. strains was amplified by primers CF5'-ACAGGATCCGATGAAAACGGTCAATTTCTATTTT-3' and CR5'-ACTCTCGAGATTGGGTTCTGTTCCCAAT-3'. This study proposes potential probiotic Bacillus mycoides PR04 (Accession no. OR625070) and Bacillus subtilis PR21 (Accession no. OR625072) in the application as an animal feed additive to assist in its digestibility and encourage the gut health.

Selenium Nanomaterials Enhance Sheath Blight Resistance and Nutritional Quality of Rice: Mechanisms of Action and Human Health Benefit.

In the current work, the foliar application of selenium nanomaterials (Se0 NMs) suppressed sheath blight in rice (Oryza sativa). The beneficial effects were nanoscale specific and concentration dependent. Specifically, foliar amendment of 5 mg/L Se0 NMs decreased the disease severity by 68.8% in Rhizoctonia solani-infected rice; this level of control was 1.57- and 2.20-fold greater than that of the Se ions with equivalent Se mass and a commercially available pesticide (Thifluzamide). Mechanistically, (1) the controlled release ability of Se0 NMs enabled a wider safe concentration range and greater bioavailability to Se0 NMs, and (2) transcriptomic and metabolomic analyses demonstrated that Se0 NMs simultaneously promoted the salicylic acid- and jasmonic-acid-dependent acquired disease resistance pathways, antioxidative system, and flavonoid biosynthesis. Additionally, Se0 NMs improved rice yield by 31.1%, increased the nutritional quality by 6.4-7.2%, enhanced organic Se content by 44.8%, and decreased arsenic and cadmium contents by 38.7 and 42.1%, respectively, in grains as compared with infected controls. Human simulated gastrointestinal tract model results showed that the application of Se0 NMs enhanced the bioaccessibility of Se in grains by 22.0% and decreased the bioaccessibility of As and Cd in grains by 20.3 and 13.4%, respectively. These findings demonstrate that Se0 NMs can serve as an effective and sustainable strategy to increase food quality and security.

Nanoscale ZnO Improves the Amino Acids and Lipids in Tomato Fruits and the Subsequent Assimilation in a Simulated Human Gastrointestinal Tract Model.

With the widespread use of nanoenabled agrochemicals, it is essential to evaluate the food safety of nanomaterials (NMs)-treated vegetable crops in full life cycle studies as well as their potential impacts on human health. Tomato seedlings were foliarly sprayed with 50 mg/L ZnO NMs, including ZnO quantum dots (QDs) and ZnO nanoparticles once per week over 11 weeks. The foliar sprayed ZnO QDs increased fruit dry weight and yield per plant by 39.1% and 24.9, respectively. It also significantly increased the lycopene, amino acids, Zn, B, and Fe in tomato fruits by 40.5%, 15.1%, 44.5%, 76.2%, and 12.8%, respectively. The tomato fruit metabolome of tomatoes showed that ZnO NMs upregulated the biosynthesis of unsaturated fatty acids and sphingolipid metabolism and elevated the levels of linoleic and arachidonic acids. The ZnO NMs-treated tomato fruits were then digested in a human gastrointestinal tract model. The results of essential mineral release suggested that the ZnO QDs treatment increased the bioaccessibility of K, Zn, and Cu by 14.8-35.1% relative to the control. Additionally, both types of ZnO NMs had no negative impact on the α-amylase, pepsin, and trypsin activities. The digested fruit metabolome in the intestinal fluid demonstrated that ZnO NMs did not interfere with the normal process of human digestion. Importantly, ZnO NMs treatments increased the glycerophospholipids, carbohydrates, amino acids, and peptides in the intestinal fluids of tomato fruits. This study suggests that nanoscale Zn can be potentially used to increase the nutritional value of vegetable crops and can be an important tool to sustainably increase food quality and security.

Effect of the Encapsulation Process on the Viability of Probiotics in a Simulated Gastrointestinal Tract Model Medium

The primary objective of this study was to investigate the survival rate of three species of encapsulated bacteria (Propionibacterium acidipropionicici, Propionibacterium freudenreichii, and Propionibacterium thoenii) in model solutions designed to simulate the acidity levels found within the human gastrointestinal tract. The capsules were prepared by extrusion from gelatin and sodium alginate in a 1:1 ratio on a laboratory encapsulator. The use of gelatin and sodium alginate was found to provide optimum characteristics suitable for encapsulation of live bacteria. Three strains of Propionibacterium asidirgorionici, Propionibacterium freudenreichii, and Propionibacterium thoenii were subjected to in vitro assay to evaluate their probiotic potential. The final cell survival rate of P. freudenreichii was 105 CFU/mL, indicating that this probiotic is sensitive to acidic medium. The viability of encapsulated probiotics was studied in a model medium simulating the gastrointestinal tract. It was found that alginate–gelatin capsules could provide protection to P. freudenreichii from gastric acid and lead to high levels of viable bacteria released in the intestine. Practical application: Encapsulation of Propionibacterium freudenreichii into alginate–gelatin capsules produced capsules capable of delivering live probiotic bacteria into the intestine.

Ethanol-free Cross-Linking of Alginate Nanofibers Enables Controlled Release into a Simulated Gastrointestinal Tract Model.

The use of alginate nanofibers in certain biomedical applications, including targeted delivery to the gut, is limited because an ethanol-free, biocompatible cross-linking method has not been demonstrated. Here, we developed water-stable, alginate-based nanofibers by systematically exploring post-electrospinning cross-linking approaches that used calcium ions dissolved in (1) a glycerol/water cosolvent system and (2) acidic, neutral, or basic aqueous solutions. Scanning electron microscopy proved that the fibers cross-linked in a glycerol cosolvent or pH-optimized solutions had maintained the same morphology as the ethanol-based literature control. Notably, cross-linked fibers were generally smaller in diameter than the as-spun fibers due to both chemical interactions and mass loss during cross-linking, which was supported by mass measurements, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. During stability tests wherein the cross-linked fibers were exposed to three aqueous solutions, the cross-linked fibers were stable in water and acid buffer yet swelled in phosphate buffer saline, making them useful scaffolds for pH-controlled release applications. Proof-of-concept release experiments were conducted using a simulated gastrointestinal tract model. As desired, the cargo remained encapsulated within the cross-linked nanofibers when exposed to an acidic solution that modeled the stomach. Upon exposure to a solution that mimicked the intestines, the cargo was released. We suggest that these cross-linked, alginate-based nanofiber mats hold the potential to be broadly used in biomedical and environmental applications.

The Improvement of Dispersion Stability and Bioaccessibility of Calcium Carbonate by Solid/Oil/Water (S/O/W) Emulsion.

Solid/oil/water (S/O/W) emulsion loaded with calcium carbonate (CaCO3) was constructed to raise the dispersion stability and bioaccessibility. In the presence or absence of sodium caseinate (NaCas), the particle size, Zeta-potential, physical stability, and apparent viscosity of stabilized S/O/W emulsions with different gelatin (GEL) concentrations (0.1~8.0 wt%) were compared. Combined with a confocal laser scanning microscope (CLSM), cryoscanning electron microscope (Cryo-SEM), and interfacial adsorption characteristics, the stabilization mechanism was analyzed. The bioavailability of CaCO3 was investigated in a simulated gastrointestinal tract (GIT) model. The S/O/W-emulsion droplets prepared by the NaCas-GEL composite have a smaller particle size, higher Zeta-potential, larger apparent viscosity, and better physical stability compared with GEL as a single emulsifier. CLSM results confirmed that CaCO3 powder was encapsulated in emulsion droplets. The Cryo-SEM results and interfacial adsorption characteristics analysis indicated that the NaCas-GEL binary composite could effectively reduce the interfacial tension, and the droplets form a denser three-dimensional network space structure with a shell-core structure which enhanced the stability of the system. GIT studies showed that the droplets presented higher CaCO3 bioaccessibility than the CaCO3 powder. This study enriched the theory of the S/O/W transfer system and provided theoretical support for the development of CaCO3 application in liquid food.

Physicochemical characteristics and in vitro bioavailability of licorice (Glycyrrhiza glabra L.) extract complexed using cyclic glucans

Licorice extract (LE), whose main ingredient is glabridin (GL), have various biological properties such as antioxidant and anticancer activities, however, their low solubility and bioavailability limit their application in the pharmaceutical and food industries. In this study, inclusion complexes (ICs) were developed using β-cyclodextrin (CD), 2-hydroxypropyl-β-cyclodextrin (HP), and cycloamylose (CA) to overcome the application limits of LE. The IC with cyclic glucans successfully enhanced the phase solubility of LE, and the stoichiometry of the complexes was investigated. After in vitro digestion, the bioaccessibility (% retention) of LE increased significantly in the IC samples, particularly with CA, compared to free LE. In vitro bioavailability, which was assessed using the results of bioaccessibility via the simulated gastrointestinal tract (GIT) model and permeability via Caco-2 monolayer assay, increased 2.5, 2.3, and 4.7-fold in the CD, HP, and CA ICs, respectively. This study provides a promising strategy to overcome the application limits of LE in various industries.

Influence of Carboxymethyl Cellulose on the Stability, Rheological Property, and in-vitro Digestion of Soy Protein Isolate (SPI)-Stabilized Rice Bran Oil Emulsion.

In this study, carboxymethyl cellulose (CMC) was added to soybean protein isolate (SPI)-stabilized rice bran oil (RBO) emulsion to improve its physicochemical stability and free fatty acid (FFA) release characteristics. RBO emulsions stabilized by SPI and various contents of CMC were prepared and assessed by measuring zeta potential, particle size, transmission, and microstructure, the rheological properties were analyzed by dynamic shear rheometer. In addition, its chemical stability was characterized by a storage experiment, and the FFA release was explored by a simulated gastrointestinal tract (GIT) model. It showed that the negative charge of the droplets of RBO emulsion was increased with increasing CMC content. The decrease in transmission of SPI-stabilized RBO emulsion with increasing CMC content was due to the droplets not being free to move by the special network interaction and an increase in the viscosity. According to the determination of the reactive substances of lipid hydroperoxide and thiobarbituric acid during 30 days storage at 37°C, the chemical stability of the emulsion added with CMC was enhanced compared with the SPI-stabilized RBO emulsion. In-vitro digestion studies not only evaluated the structural changes of RBO emulsions at different stages, but also found that RBO emulsion with CMC showed a higher level of free fatty acids release in comparison with that without CMC. It indicated that the utilization of CMC can improve the bioavailability of RBO emulsions.

Identification of zinc-chelating pumpkin seed (Cucurbita pepo L.) peptides and in vitro transport of peptide-zinc chelates.

In this study, pumpkin seeds peptide was purified, characterized, and evaluated for their zinc-chelating capability, as well as in vitro bioaccessibility and transportation. Raw pumpkin seeds protein hydrolysate (PSPH) was produced by papain hydrolysis. The peptide fractions with the highest zinc-chelating abilities were purified using immobilized metal affinity chromatography (IMAC) followed by gel filtration chromatography (GF). Eight peptides were identified, two of which with the lowest molecular weights were synthesized (RPKHPLK and RPKHPLSHDL) for determining potential bioaccessibility and bioavailability. Our results showed that the gastrointestinal stability of RPKHPLK-Zn and RPKHPLSHDL-Zn was higher than that of inorganic zinc salts in the simulated gastrointestinal tract model. Furthermore, the influence of the peptide zinc chelates on zinc transport was explored in vitro using Caco-2 cell monolayer model. It was also shown that both RPKHPLK-Zn and RPKHPLSHDL-Zn could increase zinc transport rate and may be used to facilitate effective zinc absorption. The result of this study may provide important implications for developing plant protein foods with higher nutritional value. PRACTICAL APPLICATION: As a potential alternative protein source, pumpkin seeds may find promising applications in plant-based foods and drinks to meet the growing market for nonanimal foods. In this study, pumpkin seed protein peptides were prepared and purified, and the zinc-chelating peptides were identified and evaluated for the abilities to promote the uptake of zinc. This type of mineral peptide chelates could be incorporated into plant-based foods to increase mineral contents, which is significantly higher in foods originated from animals. The result of our study may provide important information for food industry to increase the nutritional value of plant-based foods.

Physicochemical properties of insoluble dietary fiber from pomelo ( Citrus grandis ) peel modified by ball milling

This work is focused on the modification of insoluble dietary fiber from pomelo (Citrus grandis) peel (PP-IDF) by ball milling. Ball milling intensified water and oil holding capacity and water swelling capacity by 43.7%, 65.1%, and 107.5%, respectively. Besides, 97.1% of taurocholic acid, 45.3% of glucose, and 9.3 μg/mg of NO2− were bound by milled insoluble dietary fibers (IDFs). The oil-in-water Pickering emulsions were successfully emulsified by ball-milled PP-IDFs. The ball-milled PP-IDF for 2.0 hr (PP-IDF-BM2h) exhibited higher stability after storage owing to its relative strong electrostatic and steric repulsions intensified by milling process. A simulated three-stage gastrointestinal tract (GIT) model was employed to explore the physical stability of emulsion in the digestive system. Ball milling contributed promotion on stability emulsion but ion strength in simulated liquids predominated in affecting ζ potential. Overall, ball milling extended green protocols for modification of properties for dietary fiber, providing a promising application in food industry. Practical applications For safety consideration, materials used for food processing should be in low toxicity with less employment of chemicals. Hence, it is essential to develop a green and renewable strategy to modify properties of dietary fiber (DF) in food applications. Ball milling is a simple and low cost strategy that can effectively improve or modify physicochemical properties including crystallinity, surface potential, water and oil holding capacities, and hydrophilic and hydrophobic properties. Importantly, ball milling can treat dietary fiber in batch processing with no waste and chemicals, which is suitable for industrial applications.

The improvement of the physicochemical properties and bioaccessibility of lutein microparticles by electrostatic complexation

In this study, biopolymer microparticles were fabricated for the encapsulation and delivery of lutein by electrostatic complexation of sodium caseinate (NaCas) and sodium alginate (ALG) to improve its physicochemical stability and bioaccessibility. The lutein microparticles were determined by analysis of the particle size, zeta-potential, physical stability and microstructure. The formation mechanism of lutein microparticles was examined by Fourier transform infrared spectroscopy (FTIR) analysis. Moreover, the crystalline structure change of lutein was characterized by X-ray diffraction (XRD) and Differential scanning calorimetry (DSC). Bioaccessibility of lutein was also investigated in a simulated gastrointestinal tract (GIT) model. Lutein microparticles were rough irregular structures with larger mean particle size of 1750 ± 2.24 nm, higher physical stability and negative zeta-potential (−54.03 ± 0.38 mV) when the optimized concentration of NaCas and ALG were 2.0 wt%, respectively. FTIR analysis indicated the electrostatic interaction between the amino group of the caseinate and the carboxyl group of the alginate in the formation of microparticles. XRD and DSC analysis confirmed that lutein was encapsulated in microparticles as an amorphous state. Meanwhile, the microparticles effectively reduced the decomposition of lutein during 22 d storage at 37 °C. GIT studies showed that the microparticles presented higher free fatty acid (FFA) release and lutein bioaccessibility (51.27 ± 0.78%) than emulsions (12.83 ± 1.43%). This study provided a broad prospect for the formulation of lutein-fortified functional foods and beverages.

Food-Grade Titanium Dioxide Particles Decreased the Bioaccessibility of Vitamin D3 in the Simulated Human Gastrointestinal Tract.

Food-grade titanium dioxide (E171) particles, as a "whiteness" additive, are often co-ingested with lipid-rich foods. Therefore, we explored the impact of E171 on lipid digestion and vitamin D3 (VD3) bioaccessibility encapsulated within oil-in-water emulsions in a simulated human gastrointestinal tract (GIT) model. VD3 bioaccessibility significantly decreased from 80 to 74% when raising E171 from 0 to 0.5 wt %. The extent of lipid digestion was reduced by E171 addition in a dose-dependent manner. VD3 bioaccessibility was positively correlated with the final amount of free fatty acids (FFAs) produced by lipid digestion (R2 = 0.95), suggesting that the reduction in VD3 bioaccessibility was due to the inhibition of lipid digestion by E171. Further experiments showed that E171 interacted with lipase and calcium ions, thereby interfering with lipid digestion. The findings of this study enhance our understanding toward the potential impact of E171 on the nutritional attributes of foods for human digestion health.

Stability and Antiglycoxidant Potential of Bilberry Anthocyanins in Simulated Gastrointestinal Tract Model.

Anthocyanins from Vaccinium myrtillus fruits have been reported in vitro to exert potent radical scavenging and antiglycation activities. However, the physiological relevance of such properties remains unclear given the potential susceptibility of anthocyanin derivatives to digestive conditions. A simulated gastrointestinal tract model was thus implemented to assess the impact of gastric and intestinal phases on the chemical integrity of bilberry anthocyanins and their antiglycoxidant effects. Results demonstrated that the investigated activities as well as total and individual anthocyanin contents were marginally affected by gastric conditions. By contrast, with recoveries ranging from 16.1 to 41.2%, bilberry anthocyanins were shown to be highly sensitive to the intestinal phase. Of major interest, a much better preservation was observed for radical scavenging and antiglycation activities as attested by recovery rates ranging from 79.1 to 86.7%. Consistently with previous observations, the present study confirms the moderate bioaccessibility of anthocyanin constituents. It does however provide valuable information supporting the persistence of substantial radical scavenging and antiglycation activities at each step of the digestion process. Taken together, these data indicate that digestive conditions might not abolish the potential positive effects of bilberry consumption on both oxidative and carbonyl stresses.

Effects of probiotic bacteria of Lactobacillus acidophilus and Lactobacillus casei on aflatoxin B1 detoxification within a simulated gastrointestinal tract model

The present study was objected to assess the ability of lactic acid bacteria in the reduction of aflatoxin B1 (AFB1) in a simulated human gastrointestinal tract. In this work, eight treatments were prepared to compare the ability of noted probiotic bacteria in AFB1 reduction in different simulated gastrointestinal conditions. The results of the present study revealed a significant reduction in AFB1 in all of the treatments in which the highest reduction rate was observed by L. acidophilus in the absence of sterilized milk. Moreover, the findings showed that bacteria, gastric juice, and small intestine may contribute to the reduction of AFB1.

Fish skin gelatin-based emulsion as a delivery system to protect lipophilic bioactive compounds during in vitro and in vivo digestion: The case of benzyl isothiocyanate

To improve the stability of nutrients in the gastrointestinal tract, fish skin gelatin (FSG) was used as an emulsifier and benzyl isothiocyanate (BITC) as a model of nutrient delivery to construct a stable emulsion. Tween-based emulsions were used as controls. The emulsion stability, lipid digestion, and BITC bioavailability were investigated using a simulated gastrointestinal tract model. The in situ single-pass intestinal perfusion model was used to calculate the absorption (Ka) and effective intestinal permeability (Peff) of each sample. After digestion in the stomach, the emulsions had obvious aggregation, as shown by atomic force microscope, confocal laser scanning microscopy and cryo-scanning electron microscopy images. The release of free fatty acids from the FSG-based emulsion reached 87.5 ± 1.45% during the small intestinal digestion. The bioavailability of BITC in the FSG-based emulsion was 80.77%, which was nearly 27% higher than that of the control. At 120 min, Ka and Peff of the FSG-based emulsion reached the maximum values of 10.15 × 10−3/min and 6.48 × 10−3 cm/min, respectively, suggesting that the FSG-based emulsion could protect BITC and achieve a sustained release effect. These results show that the FSG-based emulsion delivery system is effective in encapsulating, protecting, and delivering BITC.

Encapsulation of lycopene in emulsions and hydrogel beads using dual modified rice starch: Characterization, stability analysis and release behaviour during in-vitro digestion

The application of lycopene, a potent antioxidant, is limited because of its hydrophobic nature and low chemical stability. To overcome this, different delivery systems, i.e. oil-in-water emulsions and alginate beads, have been synthesized in this study using modified rice starch for improving the stability of lycopene. Lycopene solution (in oil) was used as a control. Modified rice starch was used as it is cheap, GRAS, has better adsorption at the oil-water interface and provides higher resistance to the encapsulated lycopene against the harsh environment of the gastrointestinal tract. During storage at different temperatures (4–70 °C) for 15 days, the lycopene degradation rate was found to increase with increasing storage temperature for all delivery systems and with the type of delivery systems in the following order: solution > emulsion > alginate beads. Further, the delivery systems were passed through a simulated gastrointestinal tract (GIT) model to study the extent of lipid digestion and lycopene bioaccessibility. A positive correlation was observed between the rate and extent of lipid digestion and lycopene bioaccessibility. A significantly higher bioaccessibility of lycopene was observed for the emulsions (20.2%) over the beads (15.6%), whereas the chemical stability of lycopene was found to be significantly higher in the alginate beads (35.6%) than in the emulsions (29.5%). Overall, the results obtained suggest that the modified rice starch can be used as an innovative food-grade material for the design of different delivery systems to improve the chemical stability of lycopene and its controlled release in the gastrointestinal tract.

The physicochemical properties and gastrointestinal fate of oleosomes from non-heated and heated soymilk

Soymilk is a widely consumed food rich in lipids and proteins. The lipids are stored in a subcellular organelle known as oleosomes (oil bodies). Conventionally, soymilk is consumed after heating to reduce the intensity of beany flavor, however little information is available regarding the potential impact of heating on the physicochemical and gastrointestinal fate of oleosomes. In this study, oleosomes isolated from heated and non-heated soymilk were used to investigate the effects of thermal treatment on their physicochemical properties and digestive fate, using a simulated gastrointestinal tract model. The thermal treatment caused compositional changes in the surface proteins of oleosomes, as depicted in the SDS-PAGE results. Heating led to an increase in the particle size, and has no significant on the zeta-potential of oleosomes. On the other hand, non-heated oleosomes were much more viscoelastic. In addition, non-heated oleosomes have a slightly slower free fatty acid (FFA) release rate during digestion. After digestion, the antioxidant capacity of the digesta of the heated oleosomes was slightly stronger. This was likely due to the release of small peptides at the end of digestion. Importantly, four bioactive peptides were identified in the non-heated oleosome digesta, with three more in the heated oleosome digesta.

Steric stabilization of phycobiliprotein loaded liposome through polyethylene glycol adsorbed cellulose nanocrystals and their impact on the gastrointestinal tract

The goal of the study was to encapsulate phycobiliprotein (PBP), a seaweed bioactive compound with the help of liposome and stabilized through polyethylene glycol adsorbed cellulose nanocrystals (CNC). The study investigated the stability of CNC coating and the release of PBP compounds using a simulated human gastrointestinal tract (GIT) model. Adsorption of polyethylene glycol (PEG) with molecular weights of 400–4000 gmol-1 on desulfated CNCs (DCs) did not show any significant stability of liposomes during in-vitro GIT experiments. The effect of GIT phase on the quality characteristics of the sample revealed that the simulated gastric juice phase of GIT helps on desorption of polyethylene glycol from desulfated CNCs surface followed by precipitation of DCs. This phenomena confirmed the effective agglomeration of liposomes in the gastric phase of the GIT. The liposomes stabilized through the higher molecular weight of PEG adsorbed with DCs (i.e., DPCs-4000, DPCs-1500, and DPCs-1000) displayed a higher degree of anti-agglomeration behavior as compared to the lower molecular weight of PEG with desulfated CNCs (DPCs-600 and DPCs-400). However, liposomes stabilized through pure DCs displayed insignificant (p > 0.05) effect on the stability of PBP loaded liposomes. We concluded that the adsorption of PEG onto DCs surface was enough to stabilize PBP loaded liposomes in a mouth and saliva environment. This finding is relevant to understand the stability of CNC as coating material and PBP as core bioactive compounds in the human digestive system for potential nutraceutical and food applications.

Encapsulation of Bifidobacterium pseudocatenulatum G7 in gastroprotective microgels: Improvement of the bacterial viability under simulated gastrointestinal conditions

The oral delivery of probiotics to the colon is often challenging because probiotics tend to lose viability when exposed to the harsh conditions in the upper gastrointestinal tract, such as the highly acidic gastric fluids. Properly designed encapsulation technologies can be used to protect probiotics during their transit through the human gut. In this study, an anaerobic probiotic (Bifidobacterium pseudocatenulatum G7 or BPG7) was encapsulated within alginate microgels that also contained antacid agents to control their internal pH within the stomach. Probiotic-loaded microgels were exposed to a simulated gastrointestinal tract (GIT) model to establish the impact of gastric and small intestinal conditions on their physicochemical properties and cell viability. In the absence of antacids, no live probiotic cells were detected in the microgels after exposure to gastrointestinal conditions. Conversely, in the presence of antacids, there was only a 1.5 log CFU decrease in cell viability after incubation in simulated gastric fluids for 2 h. Subsequently, after the antacid microgels were incubated in simulated intestinal fluids, considerable amount of viable probiotic cells were still detected when CaCO3 was used as an antacid but not when Mg(OH)2 was used. Overall, these results indicated that alginate microgels containing CaCO3 as an antacid were efficient at protecting the probiotic during passage through the upper GIT. This novel encapsulation technology utilizing all food grade materials may be useful for the oral delivery of probiotics to the gut in the form of functional foods or supplements.