Gastric Digestion Research Articles

Characterizations of emulsion gel formed with the mixture of whey and soy protein and its protein digestion under in vitro gastric conditions

Partially replacing animal proteins with plant proteins to develop new products has much attention. To get knowledge of their application in emulsion gels, heat-induced composite protein emulsion gels were fabricated using the mixtures of whey protein isolate (WPI) and soy protein isolate (SPI) with the final total protein concentration of 10% (w/w). The water holding capacity (WHC), mechanical and rheological properties and microstructure of mixed protein emulsion gels prepared at different WPI to SPI ratios (100:0, 90:10, 70:30, 50:50, 30:70, 10:90, 0:100, w/w) were investigated. The ratios of WPI to SPI showed little effect on the WHC of the mixed protein emulsion gels (p > 0.05). Increasing the ratio of SPI decreased the hardness and storage modulus (G′) of mixed protein emulsion gels, whereas the porosity of mixed protein emulsion gels in the microstructure increased, as shown by CLSM. Both β-lactoglobulin and α-lactalbumin from WPI and 7 S and 11 S from SPI participated in forming the gel matrix of mixed protein emulsion gels. More protein aggregates existed as the gel matrix filler at the high soy protein levels. Interestingly, the G′ of mixed protein emulsion gels at the WPI to SPI ratio of 50:50 was higher than the sum of G′ of individual WPI and SPI emulsion gels. The whey protein network predominated the gel matrix, while soy protein predominated in the active filling effect. When subjected to an in vitro dynamic gastric digestion model, soy protein in the gels (WPI:SPI = 50:50) degraded faster than whey protein during gastric digestion. This study provided new information on the characteristics of composite protein emulsion gel fabricated with the WPI and SPI mixture.

Influence of Source Materials, Concentration, Gastric Digestion, and Encapsulation on the Bioactive Response of Brassicaceae-Derived Samples against Helicobacter pylori.

Isothiocyanates may have antibacterial activity against Helicobacter pylori, but there are different variables related to Brassicaceae-derived samples that could affect their efficacy. This work studied the influence of source variety, concentration, gastric digestion, and encapsulation of samples on their bioactive response against Helicobacter pylori. The antibacterial activity of raw sprouts (red cabbage and red radish) showed the highest antibacterial effect, which was consistent with a higher amount of isothiocyanates. It decreased with gastric digestion, regardless of sample encapsulation. By contrast, adult red radish leaves became antibacterial after gastric digestion. Antioxidant activity on H. pylori-infected gastric cells was similar in all samples and followed an equivalent pattern with the changes in isothiocyanates. Raw samples decreased intracellular reactive oxygen species production, but they lost this capacity after gastric digestion, regardless whether the compounds were free or encapsulated. Red cabbage sprouts, red radish sprouts, and red radish roots produced a decrease in nitric oxide production. It was consistent with a modulation of the inflammatory response and was associated to isothiocyanates concentration. Encapsulated sprout samples retained part of their anti-inflammatory activity after gastric digestion. Adult raw red radish leaves were not active, but after digestion, they became anti-inflammatory. The results obtained in this study have shown that several variables could have a significant impact on the bioactive properties of Brassicaceae-derived samples against H. pylori, providing a starting point for the design and standardization of samples with specific bioactivities (antibacterial, antioxidant, and anti-inflammatory) potentially useful for the treatment of H. pylori infection.

Evaluation of Protein Profiles, Bioactivity, Allergenicity and Toxicity of Peptides Generated After in silico Digestion of Common Wheat and Einkorn Wheat

The belief that ancient wheat is more beneficial than common wheat has been growing trend in recent years among the consumers. The present study aims to compare bioactive peptide, allergen peptide and toxic peptide generation after gastrointestinal digestion of modern wheat (Triticum aestivum) and ancient wheat, einkorn (Triticum monococcum var. monococcum), using in silico tools. The primary sequences of both kinds of wheat were obtained from BIOPEP-UWM and UniProtKB/Swiss-Prot database. In silico digestion was applied using BIOPEP-UWM online tool. For the simulation of gastrointestinal digestion pepsin (pH 1.3) (EC 3.4.23.1), trypsin (EC 3.4.21.4), and chymotrypsin (EC 3.4.21.1) were selected and analyzed. Homology analysis was performed for each protein sequences using EMBOSS Needle program. Toxic and allergen peptides were predicted using ToxinPred online tool and Allergen FP v.1.0. The results showed that einkorn and common wheat proteins exhibited similar properties including high similarity rate (58.72-87.40%) indicating the percentage of matches between the two sequences and the identical bioactivities for peptides generated after digestion. Most of the bioactive peptides were dipeptides and the majority of them displayed more than one bioactivities including ACE inhibitory, DPP IV inhibitory or antioxidant activity, etc. Allergen peptides generated after in silico digestion were found to be similar for both kinds of wheat. In silico gastric digestion of einkorn and wheat caused toxic peptides production, but they were disappeared after in silico intestinal digestion. In conclusion, although there is a perception related to the Einkorn that is healthier than common wheat, in silico digestion of common wheat and einkorn did not support this perception.

Changes in Phenolic Compounds and Antioxidant Capacity of Artocarpus heterophyllus Lam. (Jackfruit) Pulp during In Vitro Gastrointestinal Digestion.

An in vitro gastrointestinal digestion model was applied to investigate the effect of digestion on the phenolic compounds and antioxidant capacity of Artocarpus heterophyllus Lam. (jackfruit) pulp. The total phenol content (TPC) was determined using Folin-Ciocalteu method, and the antioxidant activities were evaluated by DPPH and ABTS assays. Phenolic compounds were analyzed using ultra-performance liquid chromatography coupled with electrospray ionization, followed by quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS/MS). The results showed that TPC was significantly higher after gastric digestion. Thirty phenolic compounds (hydroxybenzoic acids and derivatives, hydroxycinnamic acids and derivatives, and flavonoids) were identified. The antioxidant activities of the digested samples varied with the TPC, and there was a correlation between antioxidant activity and TPC. The present study implies that gastrointestinal digestion may improve TPC and increase the amount of free phenolic compounds, mainly related to changes in pH value and digestive enzymes.

Effect of fat concentration on protein digestibility of Chinese sausage

Chinese sausage is a popular traditional Chinese meat product, but its high-fat content makes consumers hesitant. The purpose of this study is to compare the nutritional differences of Chinese sausages with different fermentation times (0, 10, 20, 30 d) and fat content (the initial content was 11.59% and 20.14%) during digestion. The comparison of digestion degree, protein structure, and peptide composition between different sausages were studied through in vitro simulated digestion. Chinese sausages with high-fat content had higher α-helix, β-turn, and random coil, making them easier to digest. The fermentation process made this phenomenon more pronounced. The high-fat sausage fermented for 10 d showed the highest release of primary amino acids (about 9.5%), which was about 3.5% higher than the low-fat sausage under the same conditions. The results of peptidomics confirmed the relevant conclusions. After gastric digestion, the types of peptides in the digestive fluid of high-fat sausages were generally more than those in low-fat sausages, while after intestinal digestion, the opposite results were observed. The type of peptide reached its peak after fermentation for 20 d. These findings are of obvious significance for selecting the appropriate fermentation time and fat content of Chinese sausages.

Effect of heat treatment on lupin reactivity against rabbit polyclonal antibodies after in vitro gastrointestinal digestion

AbstractDespite the growing interest in lupin as a source of protein, due to its potential to decrease the environmental footprint of food supply, its allergenic properties have not been fully explored. This study focused on lupin's potential to induce allergic reactions in food‐sensitized individuals. The antigenic properties of lupin proteins were investigated after exposing lupin protein isolate as well as lupin flours to an in vitro digestion. The effect of thermal treatment, on the digestibility and immunoreactivity of the proteins was also investigated. Protein breakdown was analyzed by SDS‐PAGE, but also by evaluating the distribution of peptide sizes and the extent of hydrolysis via quantifying the free N‐terminal amino acid content. Immunogenicity was assessed by Western blot analysis using a commercial antibody. The individual or combined effects of the food matrix and processing were noted after gastric digestion of the lupin flours, as some of the protein fractions showed resistance toward pepsin activity and caused responses to the commercial antibodies, particularly the fractions likely associated with α‐conglutin (20 kDa) and γ‐conglutin (17 kDa). Gastric digestion of lupin flours also revealed the possibility of formation of neo‐allergens, which warrants future identification. However, after the intestinal phase, lupin proteins underwent complete hydrolysis, with no observed responses toward the specific antibody used. Nevertheless, these findings underscore the need for further research employing sera from allergic patients to lupin in order to avoid potential false‐negative results.

Stability and gastrointestinal behavior of curcumin-loaded emulsion stabilized by multi-conformation soy proteins: Influence of oil volume fraction

The aim of this work was to assess the potential of nanoemulsions stabilized by mixed soy protein with multi-conformation as curcumin carrier, and the influence of oil volume fraction on stability and gastrointestinal behavior of curcumin-loaded emulsion was investigated. Loading efficiency showed a slight increase with higher oil content, though the difference was not statistically significant. With the increase of oil, the viscosity (Pa‧s), thixotropy (area of hysteresis loop) and particle size of the emulsion increased, which facilitated the physical and chemical stability of curcumin-loaded emulsion. However, the free fatty acid release rate and bioaccessibility of curcumin was negatively correlated with the oil volume fraction and the particle size of emulsion after gastric digestion. Notably, the digestion in stomach did not affect the structure of interfacial protein, demonstrating that protein-based nanoemulsions exhibited resistance to gastric digestion. This study provides theoretical guidance for the application of protein-based emulsion in curcumin delivery.

The influence of protein oxidation on structure, pepsin diffusion, and in vitro gastric digestion of SPI emulsion.

The stability behaviors of oxidized SPI emulsions under in vitro gastric conditions and the effects of pepsin diffusion on the proteolysis of emulsions were investigated using a static gastric model and the fluorescence recovery after photobleaching method. Results showed that protein oxidation increased the particle size of droplets and decreased the viscoelasticity of the interfacial layer. Compared to the control group (82.81m2/s), the pepsin diffusivity decreased to 68.52m2/s (7LA+LOX group) due to the space hindrance of oil droplets. After gastric digestion, protein hydrolysates were re-absorbed on the oil-water interface and formed a thick layer, thereby decreasing the size of oil droplets and reducing the contents of free amino acids in gastric digesta. The protein oxidation may affect the adsorption of interfacial proteins and alter the distribution of droplets, decreasing pepsin diffusion and ultimately impairing the emulsion gastric digestion. And this should be considered in the design of emulsion as the controllable delivery system.

Bigels for controlled gastric release of ascorbic acid: Impact on rheology, texture, thermal stability and antioxidant activity

Ascorbic acid (AA) is a vital nutrient to maintain critical physiological functions but is very sensitive to processing and storage. This can be overcome by using gel-based systems for controlled release of AA. This study compares various gel-based formulations such as hydrogel, emulsion gel, bigel (25 %, 50 %, and 75 % oleogel), and emulsions for thermal stability and delivery of AA, rheological and textural profile, encapsulation efficiency (>97 %), in vitro gastrointestinal release profile, and the corresponding antioxidant profile. An increase in the oleogel content increased the hardness (125 – 216 g) and viscoelastic properties (G′ and G′′) but decreased (76.16 – 25.86 %) the swelling ratio of the bigel. A spontaneous release of AA was witnessed during gastric digestion from emulsion gels (95 %), hydrogels (98 %) and emulsions, whereas a gradual and controlled gastric release of AA could be achieved by bigels. However, a sudden decrease in AA (70 – 80 % reduction) and a spike in dehydroascorbic acid (DHA, oxidized AA) could be observed during intestinal digestion. The bioaccessibility was highest for emulsion gel and bigel (87 %) and lowest for emulsions (70 %). Bigels with higher oleogel content also showed better thermal stability but their physical stability was compromised at higher temperature. The DPPH and ABTS activity was proportional to AA, while FRAP was impacted by both DHA and AA. Thus bigels could be utilised for controlled gastric release of AA with better thermal stability.

Buffering Capacity of Various Commercial and Homemade Foods in the Context of Gastric Canine Digestion

The buffering capacity (BC) of food may act as a key regulatory parameter of canine gastric digestion by influencing the activity of gastric enzymes, the solubility of dietary ingredients, the gastric breakdown of food nutrients, and, subsequently, the absorption of nutrients. To analyse a possible effect of food on gastric pH, the BC of wet, dry, and homemade dog food was quantified via an acid titration method until a pH under 2 was achieved. Wet food had the highest BC; between dry and homemade food, there was no significant difference. Using multiple regression analyses, we were able to establish associations between the nutrient composition and the BC of the dog food. Crude protein content was the most important factor that influenced the BC and HCl use per gram of dry matter (DM) (p < 0.001), whereas the initial pH only tended to have an influence. The ash content also tended to affect the used HCl per gram of DM, and the DM content had a significant (p < 0.05) influence on the BC per gram of DM. The excessively high ash content found in wet food could be a risk factor for gastric dilatation–volvulus syndrome because it could lead to an insufficient pH drop in the stomach. Our data indicate large differences in the BC of typical dog food; so, estimating the BC using the equations developed herein could help to design individualized dog diets, in particular for dogs with health problems such as gastric hypoacidity, gastric reflux, or gastritis. However, more research about the influence of dog-food BC on gastric pH in vivo is needed.

Alginate-Encapsulated Mycobacteriophage: A Potential Approach for the Management of Intestinal Mycobacterial Disease.

Encapsulated medication is a common method of administering therapeutic treatments. As researchers explore alternative therapies, it is likely that encapsulation will remain a feature of these novel treatments, particularly when routes of delivery are considered. For instance, alginate-encapsulation is often favoured where gastric digestion poses an obstacle. When exposed to cations (namely Ca2+), alginate readily forms gels that are resilient to acidic conditions and readily dissociate in response to mid-range pH. This action can be extremely valuable for the encapsulation of phages. The efficient delivery of phages to the intestine is important when considering mycobacteriophage (MP) therapy (or MP prophylaxis) for disseminated mycobacterial infections and chronic gastroenteritis conditions. This study presents the design and in vitro validation of an alginate-encapsulated MP capable of releasing phages in a pH-dependent manner. Ultimately, it is shown that encapsulated phages pretreated with simulated gastric fluid (SGF) are capable of releasing viable phages into simulated intestinal fluid (SIF) and thereby reducing the mycobacterial numbers in spiked SIF by 90%. These findings suggest that alginate encapsulation may be a viable option for therapeutic and prophylactic approaches to the management of intestinal mycobacterial disease, such as Johne's disease.

Digestive characteristics of astaxanthin oil in water emulsion stabilized by a casein-caffeic acid–glucose ternary conjugate

To overcome the barrier of poor oral bioavailability of astaxanthin, a stable oil-in-water emulsion was constructed using casein-caffeic acid–glucose ternary conjugates (CSC) to deliver astaxanthin, and its gastrointestinal behavior was evaluated in vitro with sodium caseinate (CSN) as a control. Results showed that, CSC-stabilized emulsion shower better resistance to the adverse conditions of the gastric environment than CSN-stabilized emulsion, and exhibited lower average particle size and aggregation (4972.33 nm, −5.93 mv) after simulated gastric digestion. Besides, after simulated intestinal digestion, the reducing capacity and astaxanthin transfer efficiency of CSC emulsion into the micellar phase were 686.74 μmol Trolox/100 mL and 26.2 %, which were 2.6 and 4.05-fold higher than that of CSN emulsion. The above results suggest that CSC can be used for better delivery of astaxanthin, which could be useful in designing foods such as functional beverages, pharmaceuticals and nutritional supplements for delivery of lipophilic bioactives.

Effect of chitosan and chitosan oligosaccharide on the interaction and in vitro gastric digestive behavior of whey protein isolate

Carbohydrate-protein interactions can improve the properties and texture of proteins. The objective of this study was to investigate the effects of pH and preheating to 90 °C on the interaction between chitosan (CS)/chitosan oligosaccharide (COS) and whey protein isolate (WPI). Additionally, by simulating in vitro gastric digestion to evaluate the digestive behavior of the CS/COS-WPI complexes when applied to protein-supplemented beverages. The results demonstrated that only CS exhibited greater efficacy in preventing the denaturation and aggregation of WPI caused by heat treatment at pH 4.0. As pH continued to expand to 6.0, changes in the strength of electrostatic interactions and the tertiary structure of proteins influenced the formation of the complex system structure. The in vitro digestion experiments revealed that CS and COS inhibition of WPI digestion in the gastric resulted in an opposite trend with an increasing ratio. We hope that this work will offer promising strategies for developing protein-enrich beverages.

A comparative investigation of anionic polysaccharides on the structure and gastrointestinal digestion of collagen fibrils

Collagen, the most abundant and widely distributed functional protein in mammals, typically assembles into collagen fibrils through side-by-side packing. The purpose of this study was to comparatively investigate the fate of sea cucumber collagen fibrils in the gastrointestinal tract when interacting with different anionic polysaccharides (fucoidan (FUC), Kappa-carrageenan (K-car), sodium alginate (SA)). Results revealed that the gel properties and viscosity values of collagen fibrils were notably enhanced, and the rate of structural alteration in collagen fibrils was reduced when K-car and SA were introduced. Conversely, in the presence of FUC, collagen fibril viscosity decreased, and the secondary structure of collagen fibrils underwent changes. FUC was found to diminish the structural stability of collagen fibrils and accelerate the gastric digestion rate, which was further exacerbated by thermal treatment. All these anionic polysaccharides were observed to facilitate the formation of collagen peptide aggregates by binding to polysaccharides during intestinal digestion. This study bridged the knowledge gap regarding the impact of anionic polysaccharides on the gastrointestinal digestion of collagen fibrils, potentially paving the way for broader applications of collagen in the food industry.

Modulating in vitro digestion of whey protein cold-set emulsion gels via gel properties modification with gallic acid and EGCG

Gallic acid (GA) and epigallocatechin gallate (EGCG), cooperated at varied ratios (1:0, 3:1, 1:1, 1:3, and 0:1), were employed to modify gel properties of calcium induced-whey protein emulsion gel. The effects of GA/EGCG on emulsion morphology, as well as gel properties and in vitro digestive behavior of the emulsion gels were investigated. Compared with emulsions without phenolics, GA/EGCG induced slightly smaller particle size and stronger electrostatic repulsion between emulsion droplets. Moreover, GA/EGCG, notably at a ratio of 3:1, promoted electrostatic and hydrophobic interactions between protein molecules and the formation of a compact and filamentous gel microstructure, resulting in a remarkable increment in the gel strength (up to 106 %). Furthermore, in vitro oral digestion, dynamic gastric digestion (using an artificial gastric digestive system, AGDS), and intestinal digestion of the emulsion gels were simulated. Particle size and protein hydrolysis results revealed that GA/EGCG was prone to weaken the physical disintegration of gels, reduce protein hydrolysis, and enhance the stability of emulsified oil droplets during dynamic gastric digestion. As a consequence, delayed release of oil droplets was observed in the gels and more free fatty acids were released in the intestinal digestion, particularly in the gel with GA/EGCG (3:1). These findings would provide novel strategies for application of phenolic compounds in developing protein gel-based delivery systems.

Exploring the potential of plant-based emulsion gels enriched with β-glucan and potato protein as egg yolk alternatives

This study investigated the microstructure, physicochemical properties, and digestibility of plant-based egg yolk (PBEY) as a potential replacement for real egg yolk (REY). The PBEY consisted of oil-in-water emulsions containing β-carotene and vitamin D in the oil phase and β-glucan and potato proteins in the aqueous phase. The potato proteins were used as natural emulsifiers and gelling agents, the β-carotene was used as a natural yellow pigment, and the β-glucan, β-carotene, and vitamin D were used to improve the nutritional profile. In aqueous solutions, β-glucan was susceptible to aggregation and precipitation. However, it remained stable in PBEY during storage, which was attributed to non-covalent interactions between the potato proteins and β-glucan. β-glucan increased the apparent shear viscosity and shear thinning behavior of the PBEY, which was attributed to its polymeric nature. The thermal gelling properties of the PBEY were also affected by β-glucan addition, with a decrease in gelation temperature and final gel strength, indicating changes in gel structure. The addition of β-glucan also increased the hardness and resilience of the egg analogs, with 2.5 wt% yielding properties like REY in terms of springiness and chewiness. The color matching theory was used to match the color of the PBEY to REY. Optimizing the concentration of β-carotene in the PBEY allowed us to successfully match the yellow color of REY. The presence of β-glucan in the PBEY increased protein hydrolysis during simulated gastric and small intestinal digestion, but it decreased lipid hydrolysis and vitamin D bioaccessibility in the small intestine. This reduced bioaccessibility was attributed to the ability of the polysaccharide to inhibit the digestion of the protein-coated oil droplets. This study provides an improved understanding of how β-glucan affects the properties of nutrient-fortified PBEY. The PBEY developed in this study may be suitable for consumers seeking healthy and sustainable plant-based alternatives to REY. However, further research is required to test the sensory properties.

Evaluation of the antioxidant activity of Tetraselmis chuii after in vitro gastrointestinal digestion and investigation of its antioxidant peptides

Tetraselmis chuii, belonging to the class Prasinophyceae, are non-toxic microalgae with a fast growth rate and high nutritional value. Currently, the simulated gastrointestinal digestibility of T. chuii and the antioxidant activities of the peptides formed during digestion are unreported. In this study, we aimed to evaluate the antioxidant activity of T. chuii during simulated gastrointestinal digestion using INFOGEST 2.0 method. We also investigated the antioxidant bioactive peptides. In vitro digestion of T. chuii involved treatment with α-amylase, pepsin, and pancreatin during the oral, gastric, and intestinal phases, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and degree of hydrolysis showed that the proteins of T. chuii were hydrolyzed into small peptides by digestive enzymes. The antioxidant activity of T. chuii increased during digestion, and the intestinal digesta had significantly higher values of 2.2-Diphenyl-1-picrylhydrazyl (DPPH) (increased 2.96-fold and 1.99-fold compared to the oral and gastric digesta, respectively), 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (increased 7.21-fold and 3.38-fold, respectively), ferric reducing antioxidant power (FRAP) (increased to 1.73-fold and 2.17-fold, respectively), and total polyphenol content (TPC) (increased to 4.61-fold and 3.26-fold, respectively). Intestinal digesta were fractionated into <5 kDa (F1), 5–10 (F2), 10–30 (F3), and >30 kDa (F4) fractions by ultrafiltration and evaluated for antioxidant activity. In the fractions, F2 indicated significantly higher antioxidant activity in the DPPH (1.24 ± 0.05 mg trolox equivalent (TE)/g sample) and FRAP (3.66 ± 0.12 mg TE/g sample) assays, while F1 did in the ABTS (47.85 ± 2.54 mg TE/g sample) and TPC (9.85 ± 0.23 mg gallic acid equivalent/g sample) assays. These results suggest that T. chuii and its digestive enzyme products can be successfully used in functional foods as potential antioxidant agents.

Influences of Yogurt with Functional Ingredients from Various Sources That Help Treat Leaky Gut on Intestinal Barrier Dysfunction in Caco-2 Cells.

The impact of yogurts made with starter culture bacteria (L. bulgaricus and S. thermophilus) and supplemented with ingredients (maitake mushrooms, quercetin, L-glutamine, slippery elm bark, licorice root, N-acetyl-D-glucosamine, zinc orotate, and marshmallow root) that can help treat leaky gut were investigated using the Caco-2 cell monolayer as a measure of intestinal barrier dysfunction. Milk from the same source was equally dispersed into nine pails, and the eight ingredients were randomly allocated to the eight pails. The control had no ingredients. The Caco-2 cells were treated with isoflavone genistein (negative control) and growth media (positive control). Inflammation was stimulated using an inflammatory cocktail of cytokines (interferon-γ, tumor necrosis factor-α, and interleukin-1β) and lipopolysaccharide. The yogurt without ingredients (control yogurt) was compared to the yogurt treatments (yogurts with ingredients) that help treat leaky gut. Transepithelial electrical resistance (TEER) and paracellular permeability were measured to evaluate the integrity of the Caco-2 monolayer. Transmission electron microscopy (TEM), immunofluorescence microscopy (IM), and real-time quantitative polymerase chain reaction (RTQPCR) were applied to measure the integrity of tight junction proteins. The yogurts were subjected to gastric and intestinal digestion, and TEER was recorded. Ferrous ion chelating activity, ferric reducing potential, and DPPH radical scavenging were also examined to determine the yogurts' antioxidant capacity. Yogurt with quercetin and marshmallow root improved the antioxidant activity and TEER and had the lowest permeability in fluorescein isothiocyanate (FITC)-dextran and Lucifer yellow flux among the yogurt samples. TEM, IM, and RTQPCR revealed that yogurt enhanced tight junction proteins' localization and gene expression. Intestinal digestion of the yogurt negatively impacted inflammation-induced Caco-2 barrier dysfunction, while yogurt with quercetin, marshmallow root, maitake mushroom, and licorice root had the highest TEER values compared to the control yogurt. Yogurt fortification with quercetin, marshmallow root, maitake mushroom, and licorice root may improve functionality when dealing with intestinal barrier dysfunction.

Chia Oil Microencapsulation Using Tannic Acid and Soy Protein Isolate as Wall Materials.

The use of proteins to produce oil-containing microcapsules has been previously analyzed; however, their chemical modification, in order to improve their performance as wall materials, is a strategy that has not been widely developed yet. This study aimed to analyze the chemical modification of the proteins through cross-linking reactions with tannic acid and to evaluate their performance as wall materials to the microencapsulation of oils rich in polyunsaturated fatty acids. The cross-linking reaction of isolated soy protein and tannic acid was carried out at pH 10-11 and 60 °C. Subsequently, emulsions were made with a high-speed homogenizer and microcapsules were obtained by spray drying. Microcapsules were characterized by particle size, morphology (SEM), total pore area and % porosity (mercury intrusion methodology), superficial properties (contact angle), and size distribution of oil droplets (by laser diffraction). Additionally, encapsulation efficiency was determined as a function of total and surface oil. Oil chemical stability and quality were studied by Rancimat, hydroperoxide values, and fatty acid profiles. In addition, a storage test was performed for 180 days, and released oil and polyphenols were determined by in vitro gastric digestion. Moreover, the fatty acid composition of the oil and the total polyphenol content and antioxidant capacity of polyphenols were analyzed. The results showed that spray-dried microcapsules had an encapsulation efficiency between 54 and 78%. The oxidative stability exhibited a positive correlation between the amount of polyphenols used and the induction time, with a maximum of 27 h. The storage assay showed that the peroxide value was lower for those cross-linked microcapsules concerning control after 180 days. After the storage time, the omega-3 content was reduced by 49% for soy protein samples, while cross-linked microcapsules maintained the initial concentration. The in-vitro digestion assay showed a decrease in the amount of oil released from the cross-linked microcapsules and an increase in the amount of polyphenols and a higher antioxidant capacity for all samples (for example, 238.10 mgGAE/g and 554.22 mg TE/g for undigested microcapsules with TA 40% versus 322.09 mgGAE/g and 663.61 mg TE/g for digested samples). The microcapsules showed a high degree of protection of the encapsulated oil, providing a high content of polyunsaturated fatty acids (PUFAS) and polyphenols even in prolonged storage times.

Preparation and characterization of bilayered microencapsulation for co-delivery Lactobacillus casei and polyphenols via Zein-chitosan complex coacervation

This study aimed to explore the feasibility of using a complex coacervation reaction of Zein and chitosan (CS) to construct bilayer microencapsulation with both hydrophobic inner core and hydrophilic outer shell as a carrier for dual-functional factors delivery, and further investigate the protective effect of this co-delivery microencapsulation on probiotics. It was demonstrated by the study that the binding of Zein and chitosan was dependent on their pH. As the pH increased, the electrostatic interactions were strengthened, leading to the formation of larger particles with a weak positive charge (ζ = 7.37 mV) (d = 2.75 μm) that could weakly electrostatically adsorb Lactobacillus casei (ζ = −0.96 mV). SEM images showed that they gradually assembled from single-layer complexes into bilayer structured Zein-chitosan complex coacervates (ZCSC). FTIR analysis confirmed the presence of hydrogen bonding in ZCSC. Specifically, compared to no polyphenols, lower polyphenols content (quercetin, 0.05%) was found to improve probiotic activity (over 6.23 × 109 cfu/mL) and encapsulation efficiency (over 19.3%), confirming the superiority of polyphenols in hybrid co-encapsulation microcapsules. In addition, during simulated gastric digestion, being encapsulated in ZCSC increased probiotic survival by 62.85% compared to free probiotics. Polyphenol-containing ZCSC further enhanced probiotic growth during storage. Finally, using the ZCSC as a fermenting agent, a new type of flavored fermented milk with multiple functions was prepared. In conclusion, this study emphasized the potential of using layered microcapsules to deliver and protect probiotics and polyphenols, providing valuable inspiration for developing new functional foods with higher bioavailability and therapeutic effects.