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Objective: Salivary pepsin has emerged as a biomarker for Laryngopharyngeal Reflux (LPR), which, however, has been questioned for its efficacy due to a lack of supporting medical data. Therefore, this study analyzed the diagnostic value of salivary pepsin for LPR and assessed a better cutoff value. Methods: Studies were searched in PubMed, Embase, and Cochrane Library from their receptions to October 1, 2021. Then, RevMan 5.3 and Stata 14.0 were utilized to summarize the diagnostic indexes for further meta-analysis. Data were separately extracted by two reviewers according to the trial data extraction form of the Cochrane Handbook. The risk of bias in Randomized Control Trials (RCTs) was evaluated with the Cochrane Risk of Bias Tool. Results: A total of 16 studies matched the criteria and were subjected to meta-analysis. The results revealed a pooled sensitivity of 61% (95% CI 50%–71%), a pooled specificity of 67% (95% CI 48%–81%), a positive likelihood ratio of 2 (95% CI 1.2–2.8), a negative likelihood ratio of 0.58 (95% CI 0.47–0.72), and the area under the receiver operating characteristic curve of 0.67 (95% CI 0.63–0.71). Subgroup analyses indicated that the cutoff value of pepsin at 50 ng/mL had a higher degree of diagnostic accuracy than that of pepsin at 16 ng/mL in cohort studies. Conclusion: The review demonstrated low diagnostic performance of salivary pepsin for LPR and that the cutoff value of 50 ng/mL pepsin had superior diagnostic accuracy. Nevertheless, the diagnostic value may vary dependent on the utilized diagnostic criteria. Therefore, additional research is needed on the improved way of identifying salivary pepsin in the diagnosis of LPR, and also longer-term and more rigorous RCTs are warranted to further assess the effectiveness of salivary pepsin.

Changes in structure of oral solid dosage forms (OSDF) elementally determine the drug release and its therapeutic effects. In this research, synchrotron radiation X-ray micro-computed tomography was utilized to visualize the 3D structure of enteric coated pellets recovered from the gastrointestinal tract of rats. The structures of pellets in solid state and in vitro compendium media were measured. Pellets in vivo underwent morphological and structural changes which differed significantly from those in vitro compendium media. Thus, optimizations of the dissolution media were performed to mimic the appropriate in vivo conditions by introducing pepsin and glass microspheres in media. The sphericity, pellet volume, pore volume and porosity of the in vivo esomeprazole magnesium pellets in stomach for 2 h were recorded 0.47, 1.55 × 108 μm3, 0.44 × 108 μm3 and 27.6%, respectively. After adding pepsin and glass microspheres, the above parameters in vitro reached to 0.44, 1.64 × 108 μm3, 0.38 × 108 μm3 and 23.0%, respectively. Omeprazole magnesium pellets behaved similarly. The structural features of pellets between in vitro media and in vivo condition were bridged successfully in terms of 3D structures to ensure better design, characterization and quality control of advanced OSDF., Graphical abstract The differences in dynamic structure of enteric pellets during dissolution in vitro and in vivo were first observed. By introducing pepsin and glass microspheres into pharmacopoeia medium, the structures of pellets were bridged.Image 1

Background Bovine colostrum (BC) and chicken egg contain proteins possessing growth factor activity. Epidermal growth factor (EGF) provides much of the pro-reparative activity within BC. Clinical use of orally administered peptide growth factors is hampered by digestion from pancreatic proteases. Objectives We examined whether adding a protease inhibitor [soybean trypsin inhibitor (SBTI) or ovomucoid] protected bioactivity of BC ± egg or EGF alone against pancreatic digestion using in vitro and in vivo models. Methods BC, egg, or EGF alone or in combination with trypsin inhibitors were tested for proliferative (Alamar blue) activity using human gastric adenocarcinoma (AGS) cells, prior to and after incubation with HCl/pepsin and trypsin/chymotrypsin. Data were analyzed using 2-factor ANOVA. Eight groups (n = 10) of adult female Sprague-Dawley rats (mean: 188.3 ± 0.8 g) received 20 mg/kg/d of BC + egg, 100 μg/d of EGF, 5 mg/d ovomucoid, or 10.8 mg/d SBTI, alone or in combination (in 1 mL 3% NaHCO3) by gavage for 9 d and dextran sodium sulfate (DSS; 5% in drinking water) for the final 7 d. Histology, microscopic damage score, and myeloperoxidase (MPO) were assessed and analyzed using 1-factor ANOVA. Results Proliferative activities of BC, egg, or EGF were reduced 40–57% by HCl/pepsin exposure and further reduced 14–24% by chymotrypsin/trypsin. Co-addition of SBTI or ovomucoid truncated the decrease in proliferative bioactivity caused by chymotrypsin/trypsin by 54–100% (P

In this study, the effect of long-term use drugs of cholesterol-lowering atorvastatin and simvastatin on the activity and molecular structure of pepsin as important gastric enzyme was investigated by various experimental and computational methods. Based on the results obtained from fluorescence experiments, both drugs can bond to pepsin and quench the fluorescence intensity of protein through the static quenching mechanism. Also analysis of the thermodynamic parameters of binding the drugs to pepsin showed that the main forces in the complex formation for both are hydrophobic interactions and van der Waals forces. The effects of the drugs on the enzymatic activity of pepsin were then investigated and results showed that in the presence of both drugs the catalytic activity of the enzyme was significantly increased in lower (0.3–0.6 mM) concentrations however about the atorvastatin, increasing the concentration (0.9 mM) decreased the protease activity of pepsin. Also as a result of the FTIR studies, it was found that binding of the drugs to protein did not significant alteration in the structure of the protein. In order to obtain the atomic details of drug-protein interactions, the computational calculations were performed. The results in good agreement with those obtained from the experimental for interaction; confirm that the drugs both are bind to a cleft near the active site of the protein without any change in the structure of pepsin. Overall from the results obtained in this study, it can be concluded that both simvastatin and atorvastatin can strongly bond to a location close to the active site of pepsin and the binding change the enzymatic activity of protein.

There is emerging evidence on the importance of food-derived bioactive peptides to promote human health. Compared with animal derived proteins, plant proteins, in particular oilseed proteins, are considered as affordable and sustainable sources of bioactive peptides. Based on our previous bioinformatic analysis, five oilseed proteins (flaxseed, rapeseed, sunflower, sesame and soybean) were enzymatically hydrolysed using alcalase and pepsin (pH 1.3 and pH 2.1). Further, low molecular weight (Mw ​, Graphical abstract Image 1, Highlights • Bioactive capabilities of protein hydrolysates show overall limited correlation compared to in silico prediction. • Apart from DPP-IV inhibition, low Mw fractions tend to exert more promising biological activities. • In vitro analysis supports oilseed proteins, especially soybean, as good sources of bioactive peptides. • Confirmation of in vitro release of predicted peptides is needed.

Pepsin, as the main protease of the stomach, plays an important role in the digestion of food proteins into smaller peptides and performs about 20% of the digestive function. The role of pepsin in the development of gastrointestinal ulcers has also been studied for many years. Edible drugs that enter the body through the gastrointestinal tract will interact with this enzyme as one of the first targets. Continuous and long-term usage of some drugs will cause chronic contact of the drug with this protein, and as a result, the structure and function of pepsin may be affected. Therefore, the possible effect of atenolol and diltiazem on the structure and activity of pepsin was studied. The interaction of drugs with pepsin was evaluated using various experimental methods including UV-Visible spectroscopy, fluorescence spectroscopy, FTIR and enzymatic activity along with computational approaches. It was showed that after binding of atenolol and diltiazem to pepsin, the inherent fluorescence of the protein is quenched. Determination of the thermodynamic parameters of interactions between atenolol and diltiazem with pepsin indicates that the major forces in the formation of the protein-drug complexes are hydrophobic forces and also atenolol has a stronger protein bonding than diltiazem. Additional tests also show that the protease activity of pepsin, decreases and increases in the presence of atenolol and diltiazem, respectively. Investigation of the FTIR spectrum of the protein in the presence and absence of atenolol and diltiazem show that in the presence of atenolol the structure of protein has slightly changed. Molecular modeling studies, in agreement with the experimental results, confirm the binding of atenolol and diltiazem to the enzyme pepsin and show that the drugs are bind close to the active site of the enzyme. Finally, from experimental and computational results, it can be concluded that atenolol and diltiazem interact with the pepsin and change its structure and protease activity.

The rural tribal people of Meghalaya depend mostly on their ethnic fermented foods as a part of their regular diet and these fermented foods are considered to be a hub of healthy microorganisms. However, the efficacy of probiotic microorganisms is considered to be population-specific because of gut microflora variation in food habits and specific host-microbial interactions. Hence, a strong need for exploring novel indigenous microorganisms with rich probiotic potentiality is required. A few indigenous Lactobacillus isolates (from traditional fermented foods of Meghalaya) were studied extensively for its technological and probiotic attributes. The isolates could survive at pH 2–3 (L. fermentum K16 showed high cell count: pH 2–5.12 log CFU/ml; pH 3–5.76 log CFU/ml), against bile salts (L. fermentum K7 showed high cell count-5.36 log CFU/ml), gastric juices (pepsin and trypsin), and intestinal juice (pancreatin). The isolates showed α-galactosidase activity from 0.104-0.412 μM/ml and β-glucosidase activity ranging from 0.122-0.409 μM/ml. Exopolysaccharide production was in between 410 and 950 mg/L. Cell surface hydrophobicity was 71.57% (L. rhamnosus K4E) and auto-aggregation was 83% (L. fermentum K16) during the study. Highest proteolytic activity (0.671 nm) and cholesterol assimilation (52.57%) was exhibited by L. fermentum K16. The isolates showed high free radical scavenging activity by ABTS method up to 80.78% by isolate L. fermentum K7. Antibacterial activity and co-aggregation efficacy was also tested against B. cereus, E. faecalis, S. dysenteriae, S. aureus, E. coli, L. monocytogenes, S. typhi. These indigenous Lactobacillus isolates with high probiotic potentials could be exploited in the development of the traditional fermented foods of Meghalaya., Graphical abstract Image 1, Highlights • Technological and probiotic attributes (in vitro) of eight indigenous Lactobacillus strains were studied. • Lactobacillus strains were isolated from the traditional fermented foods of Meghalaya, India. • L. rhamnosus K4E, L. fermentum K16, L. fermentum K7 and L. plantarum RD7 were considered predominant over the rest of the strains. • The isolates could be employed for development of novel functional fermented foods.

Soy protein products are widely used as high nutrient sources in many food industries. However, allergenic proteins make it as one of the “big 8” foods. The objective was to analyze the molecular size, changes in protein structure and immunoreactivity of ethanol extracted soy protein concentrate in comparison with other major commercial soybean protein products extracted at different pH, and allergen stability after pepsin hydrolysis. The results showed that immunoreactivity of defatted soy white flakes (SPC2) was 227.7 mg IgE/kg protein or 102.4 mg IgE/kg product based on enzyme-linked immunosorbent assay (ELISA), the highest compared with other soy products; soy protein isolate (SPI) was the lowest (76.7 mg IgE/kg protein). Solubility of most allergenic proteins was higher at pH 12 than at pH 8.2, and the lowest at pH 2, especially no s-conglycinin was extracted at pH 2. These results contribute to the understanding of the mechanism of immunoreactivity reduction in Soycomil and demonstrate competitive advantages compared to other soy protein products.

Black cumin (Nigella sativa) seed protein (BCSP) was individually hydrolyzed with pepsin, trypsin, and α-chymotrypsin. After ultrafiltration, the α-chymotrypsin hydrolysate (

Edible insects have been important sources of food proteins for human consumption and animal feed. In this study, a protein isolate from Pterophylla beltrani Bolivar & Bolivar, 1942 (Orthoptera: Tettigoniidae) was enzymatically processed and its nutraceutical properties were evaluated. Protein isolates were obtained from an insect flour and then was hydrolyzed for 5 h with a sequential process using pepsin and trypsin-chymotrypsin to simulate the gastric intestinal fluids. To evaluate the effect of peptide molecular size on nutraceutical properties, the peptides obtained from Total hydrolyzed (TH) were fractionated by ultrafiltration (UF) with 10 kDa and 3 kDa UF membranes giving fractions (F) with different molecular size (F 10KDa). The inhibition assay of Angiotensin-Converting Enzyme (ACE) showed that the best treatment (P 10KDa and F 0.05) was found between the TH and F

Lovastatin is a typical drug interacting with grapefruit juice and naringin and vitamin C are main active constituents in fruit juice. It is necessary to study the interaction between lovastatin and digestive enzymes and the effect of naringin and vitamin C on the interaction. Pepsin, trypsin and α-chymotrypsin were selected as representatives of digestive tract enzymes, and fluorescence spectroscopy was employed to study the interaction of lovastatin with three digestive enzymes and the effect of naringin and vitamin C on this interaction. The mechanism of interaction between lovastatin and three digestive enzymes was static quenching. Lovastatin bound to trypsin by electrostatic interaction, while bound to pepsin or α-chymotrypsin mainly by hydrophobic interaction. The conformation of three enzymes changed and non-radiative energy transfer occurred with high probability between three digestive enzymes and lovastatin. Both naringin and vitamin C could reduce the binding stability of lovastatin to pepsin and α-chymotrypsin, increasing concentration of free lovastatin. That is, naringin or vitamin C in the fruit or food may increase the blood concentration of lovastatin; perhaps taking frequency or dosage of lovastatin may be reduced.

This study was aimed at isolation of pepsin-solubilised collagen (PSC) from Mackerel (Scomber japonicus) bone and skin in order to effectively valorise these abundant wastes. The yield of PSC (8.10%) from skin was considerably higher than that from bone (1.75%). Based on the protein patterns, both PSCs were type Ι, and consisted of two α-chains. Fourier-transform infrared spectra demonstrated that PSCs from the bone and skin exhibited a triple-helical structure. The denaturation temperatures (Td) of the PSCs from bone and skin were 27 and 30 °C, respectively. Low-molecular-weight peptides (

Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrheal disease among children in developing countries, and there are no licensed vaccines to protect against ETEC. Passive immunization by oral delivery of ETEC-specific secretory IgAs (sIgAs) could potentially provide an alternative approach for protection in targeted populations. In this study, a series of physiochemical techniques and an in vitro gastric digestion model were used to characterize and compare key structural attributes and stability profiles of 3 anti–heat-labile enterotoxin mAbs (sIgA1, sIgA2, and IgG1 produced in CHO cells). The mAbs were evaluated in terms of primary structure, N-linked glycan profiles, size and aggregate content, relative apparent solubility, conformational stability, and in vitro antigen binding. Compared to IgG1 mAb, sIgA1 and sIgA2 mAbs showed increased sample heterogeneity, especially in terms of N-glycan composition and the presence of higher molecular weight species. The sIgA mAbs showed overall better physical stability and were more resistant to loss of antigen binding activity during incubation at low pH, 37°C with pepsin. These results are discussed in terms of future challenges to design stable, low-cost formulations of sIgA mAbs as an oral supplement for passive immunization to protect against enteric diseases in the developing world.

The use of the pesticide imidacloprid can be hazardous to human health. In this work, the impacts of imidacloprid on the secondary structure of pepsin were investigated through spectroscopic techniques and simulation studies. One binding site for pepsin with strong affinity was evident from changes in the fluorescence emission spectra of pepsin in the presence of imidacloprid. Calculated thermodynamic parameters based on the van't Hoff relationship indicate the predominance of hydrophobic and hydrogen bonding interactions contributing to the imidacloprid-pepsin complex. Structural changes in pepsin were also evident from changes in the UV, FTIR, CD, three-dimensional fluorescence (3D), and synchronous fluorescence spectroscopy (SFS) of pepsin upon titration with imidacloprid. Furthermore, density functional theory (DFT) calculations and molecular docking studies revealed predominant binding of imidacloprid in the hydrophobic pocket of pepsin.

The microencapsulation and controlled release of pepsin have been achieved by spray drying with the original, hydrolysed and gelled whey protein isolates (WPI, HWPI, GWPI). The pepsin is in an amorphous state in the spray-dried particles. The survival rate of pepsin is around 84.3–89.4% during spray drying and decreases with increasing inlet temperature from 110 to 190 °C. The optimal inlet temperature for a high yield and a high survival rate of pepsin is 150 °C. The spray-dried proteins have wrinkled surfaces, which are related to high Peclet numbers during drying. FTIR spectra show free amino acids for HWPI and the change in protein structure for GWPI upon gelation, compared with WPI. The spray-dried samples with microencapsulated pepsin have been tableted for the controlled release studies. The release time is controllable within 4 h by changing the release matrices or the pepsin ratio. Zero-order release of pepsin has been relatively achieved with the highest R-squared value of 0.989 using a sandwich-like multilayer design for a matrix containing 50% GWPI and 50% WPI.

In this study, the binding characteristics of aloe-emodin (AE) and pepsin were investigated via multiple spectroscopic and molecular docking methods. The Stern-Volmer quenching constant (Ksv) suggested that AE quenched the fluorescence intensity of pepsin via static quenching. The value of the stoichiometric binding number (n) suggested only a single binding site on pepsin for AE. The value of Gibbs’ free energy change (ΔG)

In the present study, the proximal composition of selected Indian seaweeds such as S. wightii, E. compressa, A. spicifera and their polysaccharide extraction by various enzymes (pancreatin, cellulase and pepsin) was carried out along with its detailed characterisation. In addition, their antioxidant activity and prebiotic score was evaluated with L. plantarum and S. typhimurium. SCFA composition was analyzed by liquid chromatography. Dietary fiber was found to be maximum in E. compressa (60.64 ± 2.2%). The polysaccharide obtained by combined enzyme assisted extraction exhibited higher antioxidant activity. E. compressa (1.44) exhibited the highest prebiotic activity score, followed by S. wightii (1.42) and A. spicifera (0.84). Plantaricins of L. plantarum exhibited equal and enhanced inhibition activity of 1.3 ± 0.1 cm against gut pathogens such as S. aureus, S. flexneri, E. coli and S. typhimurium, while compared to MRS broth cultivation. The results indicate that the combined enzyme extract of seaweed polysaccharides could act as a potential prebiotic compound with extraordinary antioxidant activity and prebiotic efficiency.

The addition of microbial transglutaminase (MTGase) in surimi gel protein promote cross-linking and improvement of textural properties. In this study, the effects of cross-linking by MTGase on digestibility by pepsin were investigated using different methods, including, scanning electron microscopy (SEM), particle size, dry matter digestibility, Tricine SDS-PAGE, LC-MS/MS, and analysis of amino acids. Gel properties and cross-linking of surimi gels increased significantly (P

Summary Objectives Vocal fold nodules (VFNs) are benign disorders affecting the superficial lamina propria of the true vocal folds. The etiology of VFNs still remains unclear but laryngeal trauma caused by vocal abuse, tobacco, alcohol, and laryngopharyngeal reflux (LPR) plays a crucial role on the pathogenesis. The aim of this study was to assess the presence of pepsin in formalin-fixed, paraffin-embedded (FEPE) specimens of VFNs to evaluate the role of LPR as a risk factor for VFNs. Materials and Methods A total of 28 pathology specimens of patients suffering from VFNs who had undergone laser microsurgery under general anesthesia were evaluated. The specimens were maintained in paraffin blocks in the pathology department. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) analyses were used to measure pepsin enzyme levels in the VFNs tissue specimens. Signs of LPR were assessed according to the reflux finding score. Results The mean reflux finding score of the patients was 13.6 ± 2.89 (8–21). According to WB and ELISA analyses, pepsin was detected with both the WB the ELISA tests in positive controls, but there was no pepsin enzyme in any of the 28 laryngeal FEPE VFNs specimens. Conclusion The pepsin enzyme was not detected in any of the FEPE VFNs specimens, and it is concluded that further studies are needed to reveal the role of pepsin in the etiology of VFNs.

International audience; Carotenoids are lipophilic phytochemicals; their intake has been associated with reduced chronic diseases. However, their absorption depends on emulsification during digestion and incorporation into mixed micelles, requiring digestive enzymes, gastric peristalsis, bile, and dietary lipids. In this study, we investigated whether whey-protein-isolate (WPI), a commonly consumed protein source, can modulate β-carotene bioaccessibility in vitro, especially under incomplete digestive conditions, i.e. under low digestive enzyme concentrations. Thus, amounts of pepsin, pancreatin, bile, co-digested lipids and kinetic energy and gastric digestion time were modified, and WPI at concentrations equivalent to 0/25/50% of the protein recommended dietary allowance (approx. 60 g/d) were added to β-carotene dissolved in oil. WPI enhanced bioaccessibility by up to 20% (p

Summary Background Laryngopharyngeal reflux (LPR) is commonly treated with empiric acid suppression. More evidence points to pepsin in the pathophysiology of LPR. Previous studies have evaluated esophageal impedance in patients who had previously failed high dose proton pump inhibitor (PPI) using older catheters without proximal esophageal (just under the upper esophageal sphincter) and pharyngeal impedance sensors. The aim of this study was to compare what traditional diagnostic tools, used for esophageal reflux, would detect and diagnose compared with what a combined hypopharyngeal-esophageal MII catheter with dual pH (HEMII-pH) can detect in the esophagus and pharynx in patients with suspected LPR. Methods Forty-two subjects with presumed LPR were referred for HEMII-pH testing. The number of distal and proximal esophageal impedance events, number of pharyngeal impedance events, symptom correlation, and event acidity were recorded. Previous normative values (>1 pharyngeal impedance events every 24 hours) were used to designate what was pathological LPR on HEMII-pH. Results Forty-two total subjects had pharyngeal impedance sensor data recorded. Twelve (28.6%) of the subjects were tested while taking high-dose PPI therapy. The mean number of proximal esophageal events was 23.3. The mean number of pharyngeal impedance events was 10. Thirty-four subjects (81%) tested positive for pharyngeal reflux. All patients who tested positive using traditional proximal impedance criteria also tested positive using pharyngeal criteria. Of patients who tested negative using traditional criteria, 72% were positive based on pharyngeal criteria. Conclusions HEMII-pH catheters should be considered in patients with LPR symptoms. Traditional criteria used for diagnosing esophageal reflux may not translate into LPR.

Coconut milk has high nutritive value. In this study, we attempted to assess the gastrointestinal digestion of coconut milk proteins in vitro. Cow's milk and coconut milk proteins were subjected to two successive hydrolyses with pepsin then with a mixture of trypsin/chymotrypsin. The kinetics of degradation were determined and SDSPAGE was carried out to evaluate specific protein composition before and after α-NH2 free-function analysis. Determination of α-NH2 free functions showed coconut milk proteins to be more susceptible to both pepsin digestion (***p

Fish collagen is gaining immense interest because the use of mammalian collagen is restricted due to disease transmission and religious issues. So, collagen was extracted and characterized from three different parts (skin, scale, and bone) of bigeye tuna using the acid and pepsin extraction methods. The yield of acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) in skin were 13.5 ± 0.6% and 16.7 ± 0.7%, respectively, on a dry basis. The yields of PSC in scale and bone were 4.6 ± 0.3% and 2.6 ± 0.3%, respectively, while ASCs were in negligible amount. All the extracted collagens were type I collagen and a high level of imino acids (227–232/1000 residues) was found in all the extracted collagens. The thermal transition temperature (31.6–33.7 °C) and thermal denaturation temperature (31.1–32.2 °C) were higher than those of many temperate- and cold-water fish collagens. All collagens were highly soluble at acidic pH. The isoelectric points were 6.1, 6.4, 5.4, and 5.5 for skin-ASC, skin-PSC, scale-PSC, and bone-PSC, respectively. Therefore, the high collagen contents, especially in the skin, and higher thermal properties of the extracted collagens suggested that they have great potential for use as an alternate for mammalian collagen.

Fishmeal (FM) possesses one of the highest buffering capacities in comparison to most alternative vegetable aquafeed ingredients and its decreasing content in current formulations might affect the ideal gastrointestinal environment for digestive enzyme action and gut bacterial community of carnivorous fish species. A study was undertaken, therefore, to assess growth response, gastrointestinal pH, digestive enzyme activity and gut bacterial community of European sea bass (Dicentrarchus labrax L.) juveniles fed low FM diets (10% FM) with or without a feed buffering additive, calcium carbonate (FM10 + B and FM10, respectively) in comparison to a standard FM diet (20% FM, FM20). Three isonitrogenous and isolipidic extruded diets were fed to triplicate fish groups of 80 individuals (initial weight: 23 g) to overfeeding over 64 days. No significant differences due to low FM dietary levels were observed in final body weight, specific growth rate, feed intake, feed and protein efficiency. Low FM diet did not affect gastrointestinal pH in the stomach, anterior intestine, mid-intestine and hindgut at 0, 4, 8 and 12 hours post meal (hpm) while the inclusion of calcium carbonate in low FM diet seems to slightly increase the pH in the hindgut at 12 hpm. The absence of significant differences of pepsin, chymotrypsin, amylase and lipase activity suggests a comparable digestive efficiency among treatments although trypsin activity was slightly reduced in low FM diets after 4 hpm. Decreasing FM content seems to exert an effect on the overall gut bacterial community analysed by next-generation sequencing even if no significant effects on specific bacterial component were detected. The gut bacterial community in all the treatments was particularly rich in lactic acid bacteria such as Lactobacillus spp. which may provide important beneficial functions for the host and be associated with a healthy intestinal epithelium. According to the results, increasing the feed buffering capacity does not seem to improve digestive conditions while it is feasible to include 10% FM dietary level in practical formulation for European sea bass juveniles without negatively affecting growth, feed efficiency and digestive luminal conditions. info:eu-repo/semantics/publishedVersion

The stomach is a major digestive organ of the human body that plays a role in storing, mixing, reducing chylous particles and breaking down ingested foods. This study established a new artificial gastric digestive system (AGDS) with a human stomach shape and structure by a 3D digital technology. Two sets of symmetrical rollers and one set of contrary movement of the roller were used to simulate the peristalsis of the stomach, and a pH-stat workstation was applied to control the pH. The force, pepsin and gastric juice secretion, gastric emptying and pH changes of AGDS were tacked and validated. Besides, the digestion behavior of α-lactalbumin using AGDS model, static model and semi-dynamic model (pH and enzyme changes) were studied. The results showed that the hydrolysis and morphology of protein, peptide and amino acids accumulation obtained by AGDS were different from the static digestion and semi-dynamic digestion models, indicating pH and gastric motility had certain effect on protein hydrolysis, particularly in the pepsin activity changes at early stage of digestion. AGDS, verified by mechanical analysis and in vitro digestion experiments, indicated that it can provide α-LA protein solution with a true and reliable digestion profile in the stomach, and can be used as a potential dynamic gastric digestion model for the food development.

Protein hydrolyzates of Stripped weakfish (Cynoscion guatucupa) industrial byproducts were prepared, and their antimicrobial and antioxidant activities, as well as bioaccessibility were evaluated. Byproducts were hydrolyzed by Alcalase (HA) and Protamex (HP) to achieve degrees of hydrolysis (DH) of 5, 10 and 15%, respectively. Resulting hydrolyzates were enzymatically digested with pepsin and pancreatin to determine the in vitro bioaccessibility. The highest antimicrobial activity was verified for HA with DH 5% (HA5) against Escherichia coli O157:H7 (5.50 ± 0.17 mm). Whereas HP with DH 5% (HP5) showed the highest antioxidant activity for the tested assays. After simulated in vitro gastrointestinal digestion, all samples were bioaccessible and showed an increase for the ABTS and hydroxyl radical scavenging with the highest activities for HA5 (87.7 ± 0.21%) and HP5 (87.5 ± 0.34%) and HP5 (96.7 ± 0.86%) and HP15 (97.5 ± 0.15%), respectively. We then submitted HA5 and HP5 to peptide sequences analysis, the bioactivities were attributed to the presence of amino acid such Phe, Leu, and Trp in the peptide sequences and peptide sequences like WDDMEK (HP5). The developed peptides present a potential for use as natural antimicrobial and antioxidant preservatives in food.

This is a study of microstructure changes and Soybean milk colloidal particles degradation during in vitro digestion. Soybean milk passed through the digestion stages of the Infogest protocol, while its colloidal particles were examined in terms of size decrease/free surface evolution kinetics and of surface charge. Colloidal protein break-down was determined in relation to the digestion stage, and the shape and structure of the soybean milk particles were monitored with confocal microscopy. Gastric digestion significantly influenced the soybean milk particles, increasing the particle size and decreasing absolute surface charge, hydrolyzing protein and accumulating aminoacids. Similar breakdown was not observed in the absence of pepsin, so the protein break-down can be primarily attributed to pepsin-induced hydrolysis. Correlation of the aminoacids release kinetics with the changes in surface area of the soybean milk proteins showed a direct relation between aminoacids release and solid-water interface formation. A sequence of events can be proposed where proteins are exposed and hydrolyzed throughout the simulated gastrointestinal tract as new interface (substrate) is created in the soybean milk colloidal systems.

Antioxidant peptides were successfully identified from a finger millet protein hydrolysate. The trypsin hydrolysate showed a higher degree of hydrolysis (17.47 ± 0.63%) than the pepsin hydrolysate, was further fractionated by ultrafiltration membrane [ 10 kDa (UF1)]. UF3 with higher antioxidant activity (48.41 ± 0.21%) was further fractionated into five fractions (GFA, GFB, GFC, GFD and GFE) using gel filtration. Fraction GFB possessed the highest antioxidant activity (61.79 ± 0.08%) and was purified by reverse-phase ultra-flow liquid chromatography. Two potential antioxidant peptides were identified as TSSSLNMAVRGGLTR and STTVGLGISMRSASVR. Synthetic peptides with the same sequence were synthesized and characterized for their antioxidant activity. Molecular docking studies revealed that potential antioxidant activity from both peptides resulted from the interaction of serine and threonine residues with free radicals. The current study suggested that natural peptides identified from finger millet have potent antioxidant activity and regarded as a promising source for a functional food ingredient.

A vasorelaxant whey hydrolysate at semi-pilot scale was generated, assessing the influence between two different enzyme inactivation conditions (pH and temperature) and drying technologies (freeze- and spray-drying). Hydrolysis was performed with 1.25% (w/v) whey protein concentrate solution and 1.91% (w/w) pepsin (pH 2, 3 h, 37 °C). Reactions were stopped either by increasing the pH to 7 (5 m NaOH) or by heating the solution at 80 °C for 5 min. Thermally inactivated samples induced a vascular relaxation ex vivo above 70%, while the chemically inactivated ones reached only 20%. Both drying technologies were effective in maintaining the bioactivity of the hydrolysate. These results brought the possibility of developing a whey-based product with high vasorelaxant potential in semi-pilot scale; thermal treatment followed by spray drying seemed to be the more affordable alternative for food and nutraceutical industries to generate this bioactive product.

Pepsinogen I (PG I) and pepsinogen II (PG II) are gastric disease-associated proteins that have been utilized as biomarkers for gastric cancer screening. However, the current methods for detecting PG I and PG II can barely satisfy the needs of mass screening, especially in remote areas. In this study, a rapid and sensitive fluorescent immunochromatographic test strip with a miniature analytical device (20.0 cm × 18.9 cm × 11.2 cm, 2.4 kg) was developed for the simultaneous determination of PG I and PG II in one sample in a single assay, which is promisingly suitable for the mass screening of gastric cancer. Under the optimum conditions, PG I and PG II concentrations as low as 2.6 ng/mL and 1.0 ng/mL could be detected in 15 min with only 7.5 μL plasma specimen, and no cross-reactivity was observed. The detection range was linear over 10.0–210.0 ng/mL for PG I and 3.0–63.0 ng/mL for PG II. The immunosensor also demonstrated high recoveries (93.6–110.8% for PG I and 95.4–110.4% for PG II) with low coefficient of variation (CV) (4.8–8.1% for PG I and 6.6–11.7% for PG II) when testing actual human plasma. The analyses by the proposed assay correlated well with those by ELISA of 30 spiked samples. The assay was finally applied to 30 clinical samples, and the results showed its clinical significance for the early screening of gastric cancer. Therefore, the assay proposed in this study provides a rapid, sensitive, and simultaneous detection strategy in the pepsinogen test, and the results indicated its potential capacity in the mass screening of gastric cancer.

The present study identified at least two novel angiotensin I-converting enzyme (ACE) inhibitory peptides in horse gram flour after hydrolysis with alcalase. The ACE inhibitory peptides from horse gram hydrolysate (HGH) were purified by ultrafiltration and different chromatography techniques followed by identification using nano liquid chromatography-mass spectrometry (nano LC-MS/MS). Further, based on in silico analysis, twelve potential ACE inhibitory peptides from HGH were synthesized and assayed for their ACE inhibitory activity. Two peptides TVGMTAKF and QLLLQQ exhibited the highest ACE inhibitory activity (IC50 values of 30.3 μM and 75.0 μM, respectively) and were characterized kinetically to show Ki values of 0.01 μM and 0.18 μM, respectively. In addition, these two novel peptides exhibited competitive mode of inhibition as well as retained their ACE inhibitory activity after incubation with gastrointestinal proteases (pepsin, trypsin, and chymotrypsin). Thus, the ACE inhibitory peptides identified from HGH shows promise to be used as a functional food ingredient for controlling hypertension.

In a conventional microorganism-mediated biological process for degradation of keratinous waste material the production of keratin-specific proteases (i.e., keratinases) and the hydrolysis of keratin-rich residual biomass both take place during the same stage of the bioprocess and, as a consequence, occur simultaneously under suboptimal conditions. In the present study the keratinolytic actinomycete Amycolatopsis keratiniphila D2 was successfully employed to biodegrade thermally pretreated porcine bristles at high solids loading (16% w/v) via a novel cultivation methodology. Indeed, the two-stage submerged fermentation process developed in this work enabled to efficiently recover, in a single unit operation, about 73% of the protein material contained in the keratinous biowaste structure, resulting in an overall accumulation of 89.3 g·L−1 protein-rich hydrolysate and a productivity of 427 mg crude soluble proteins per litre per hour. The obtained protein hydrolysate powder displayed a 2.2-fold increase in its in vitro pepsin digestibility (95%) with respect to the non-hydrolysed pretreated substrate (43%). In addition, the chromatogram obtained by size-exclusion chromatography analysis of the final product indicated that, among the identified fractions, those consisting of small peptides and free amino acids were the most abundantly present inside the analysed sample. Given these facts it is possible to conclude that the soluble proteins, peptides and free amino acids recovered through the newly designed two-stage bioextraction process could represent a viable alternative source of protein in animal feed formulation.

Lactoferrin hydrolysates (LF-H) were digested using pepsin and modified using a pepsin-catalyzed plastein reaction with tryptophan (Trp) to obtain a target product. LF-H, the target product, plastein reaction-modified LF-H alone, and a mixture of LF-H and Trp were evaluated for their activities with human gastric cancer BGC-823 cells at 24 and 48 h. Assay results indicated that the target product had decreased free amino groups and had incorporated Trp. LF-H and the plastein reaction-modified LF-H alone did not show detectable growth inhibition on BGC-823 cells at 1–3 mg/mL; however, the target product at the same dose levels inhibited cell growth, and showed higher activity than the mixture (P

This work aimed to improve yield of collagen from the grass carp skin by employing different strategies (acid-acid method, pepsin-pepsin method and acid-pepsin method, denoted as A-A, P-P, A-P, respectively). And further to conduct quantitative characterization on structural properties, self-assembly kinetics and gelation properties of these collagens. Herein, a two-step collagen extraction method (pepsin-pepsin) was established with the high yield. Meanwhile, structural measurements of high-yield collagen (pepsin-soluble collagen, PSC) and acid-soluble collagen (ASC) indicated that both collagens maintained the typical triple helical conformation of collagen type I. Moreover, the fibrillogenesis tests of PSC and ASC at the various temperatures confirmed that self-assembly were the entropy-driven process. The gelation time of both ASC and PSC was determined by the dynamic time sweep at the different frequencies combined with Winter's criterion. The self-assembly kinetics results showed that fibrillogenesis rate for ASC solution was faster, and more liable to gelation relative to PSC. Mechanical measurements suggested that ASC showed the more resistance ability to deformation than PSC due to more complicated architecture, confirmed by higher fractal dimension. However, the equivalent typical assemblies of PSC to ASC at the various stages can still be expected via controlling incubation time or temperature under the guidance of Arrhenius equation. This study would provide some strategies for achieving maximum utilization of waste biomass and significant insights into the mechanisms underlying the quantitative differences in multiple hierarchy conformation (molecule, fibrillogenesis and hydrogel) of ASC and PSC, which may benefit for subsequent design, development and optimization of collagen-based hydrogels in biomedical industries.

Early screening of gastric cancer is a critical importance for the improvement of patients’ survival rate. Here, a polyethylene coating Lamb (PE-Lamb) microfluidic device with immune layer for gastric cancer label-free detection was constructed. Two serum pepsinogen 1 (PG1) and pepsinogen 2 (PG2) biomarkers were applied to screen and predict the appearance of gastric cancer. Compared with enzyme-linked immunosorbent assay (ELISA), this method achieved a higher sensitivity and less time (40 min vs 120 min). The limit of detections (LOD) were reached 60 pg/mL for PG1 and 30 pg/mL for PG2, which have two orders of magnitude lower than traditional ELISA. The linearity coefficient indexes (R2) for PG1 and PG2 were 0.992 and 0.953 respectively, which is similar to that of ELISA. In addition, PG1 and PG2 mixed antigens sample with human serum was detected by PE-Lamb approach, and the frequency response showed high reproducibility and specificity. The results indicate that PE-lamb diagnostic technique is a novel and promising method for high-throughput screening and early diagnosis of gastric cancer.

The effect of the gastric behaviour of protein-stabilised oil-in-water emulsions on intestinal lipid digestion was investigated using an in vitro dynamic gastric digestion model ‒ the human gastric simulator (HGS) and an intestinal model. Emulsions were prepared using milk protein concentrate (MPC), calcium-depleted MPC or sodium caseinate. In the MPC-stabilised emulsion, flocculation, induced by the milk-clotting enzyme pepsin, occurred after 10 min of digestion (at pH > 6) in the HGS. Closely knitted flocs of large size, which remained in the HGS throughout the gastric digestion, were formed. However, in emulsions stabilised by calcium-depleted MPC or sodium caseinate, flocculation occurred after approximately 40 min of digestion because of the low pH (∼pH 5); the flocs were relatively small and disintegrated after further digestion. The particle sizes of the gastric digesta mixtures obtained at each digestion time were in the order: MPC emulsion > calcium-depleted MPC emulsion > sodium caseinate emulsion. In contrast, the oil contents of the mixtures were in the order: MPC emulsion

Marine polychaetes and fish are known to ingest polystyrene microparticles in the environment. Laboratory microplastic feeding experiments have demonstrated that plastic may release endocrine-disrupting compounds such as diethylhexyl phthalate (DEHP), which can cause adverse effects in both vertebrates and invertebrates. In order to determine the influence of size and digestive conditions on the desorption of DEHP and other plasticizers to polychaetes and fish, we exposed polystyrene particles of various sizes under invertebrate and vertebrate digestive conditions (vertebrate mimic; pepsin, pH = 2.0, 24 °C, invertebrate mimic; Na taurocholate pH = 7, 18 °C). Estrogen receptor activation and concentrations of 12 plasticizers were measured in the extracts. DEHP, bisphenol S and 4-tert-octylphenol were the only compounds detected. Simulated vertebrate gut digestion did not significantly enhance the release of chemicals nor estrogenic activity. However, a 6.3 ± 2.0-fold increase in the concentration of DEHP was observed in extracts from invertebrate gut conditions (Mean ± SD; N = 24, p

Two experiments were conducted to validate a method to prepare simulated small intestinal fluid (SSIF) for in vitro digestion in ducks. Experiment 1 compared the in vitro digestible energy (IVDE) of SSIF to endogenous small intestinal fluid (ESIF) on four feeds. The ESIF 1 or 2 obtained from two groups of jejunal cannulated ducks offered diet 1 (3,050 kcal/kg of ME and 19.95% of CP) or 2 (2,801 kcal/kg of ME and 14.90% of CP) was purified into raw enzyme power (REP) 1 or 2. SSIF 1 to 3 or 4 to 6 were prepared to mimic ESIF 1 or 2, respectively. The enzyme sources were REP 1 for SSIF 1 and 4, REP 2 for SSIF 2 and 5 or reagent enzymes for SSIF 3 and 6, respectively. The IVDE of each feed was determined with SSIF or ESIF. Experiment 2 was to validate whether REP 1 was more effective than only reagent enzymes to prepare SSIF. Ten feeds were determined with pepsin following SSIF 1 or 3 for IVDE 1 or 2, respectively. The accuracy of prediction model of true metabolizable energy (TME) from IVDE 1 or 2 was evaluated to validate the efficacy of SSIF. In experiment 1, higher activities of amylase, trypsin and chymotrypsin were observed in ESIF 1 than ESIF 2 (P < 0.05). The IVDE determined with SSIF 1 and 2 or 3 and 4 were more comparable to that of ESIF 1 or 2 than determinations with SSIF 3 or 6. In experiment 2, the mean IVDE 1 or 2 was 97.22% or 96.23% relative to TME, respectively, and both were highly correlated with TME (P < 0.01; R2 ≥ 0.98). However, the residual SD of TME prediction model with IVDE 1 was less than that generated with IVDE 2 (55 vs. 71 kcal/kg). In conclusion, the IVDE determined with in vitro digestion of pepsin following SSIF prepared with REP can predict accurately TME of feed for ducks.

In the present study, the histological changes and digestive enzymatic activity patterns are described during the larval development of palm ruff, Seriolella violacea from hatching up to 50 days after hatching (DAH). At hatching, the digestive tract consisted of an undifferentiated straight tube dorsal to the yolk-sac, which presented alkaline protease activity (trypsin and chymotrypsin) as well as amylase and lipase activities with similar patterns during larval development. At 20 and 23 DAH, histology of the stomach revealed a sac-like shaped organ, with an epithelium that began to differentiate in a cardiac and a pyloric region. Typical histological structures of a stomach were visible at 33 DAH with a concomitant pepsin activity. Gastric glands were clearly visible at 35 DAH, increasing in numbers up to 37 DAH, suggesting a functional stomach at this age. A significant increase in the specific activity of all enzymes including pepsin (except amylase) was observed between days 33–35 DAH, which suggests a complete maturation of the digestive system in S. violacea larvae. Total activity from all the different enzyme activities followed the same trend as the specific activity. Based on the results from this study it might be feasible to begin weaning this species at 35 DAH, thereby reducing the amount of live food in the current protocol used which initiates weaning 45 days.

Laryngopharyngeal reflux (LPR) is common in the otolaryngologist's office, and a multimodal treatment regimen is employed often. Counseling patients on lifestyle modifications is important. Alkaline water consumption has been recommended as a nonmedical "antacid" for its value in deactivating pepsin, a proteolytic enzyme responsible for laryngeal tissue inflammatory changes in LPR. Alkaline water can be found as premade bottled water, or it can be made at home by titrating regular-pH water with concentrated alkaline drops. We present a patient who mistakenly instilled the alkaline drops into her eye, causing alkali-related chemical burns to the sclera and cornea, which subsequently resulted in scar.

The study included purification of pepsin enzyme EC: 3.4.23.1 that produced by using a mixed inoculum consisting of Staphylococcus sciuri and Pythium sp. and using the whey as a local carbon source obtained from a previous study. Pepsin was purified first by using salts of ammonium sulphate with saturation rates ranging between (30–80)%, and then the process of dialysis with distilled water, the process was performed with distilled water and the process of purification of the enzyme was completed using the DEAE-Cellulose ion exchange column and then the gel filtration using the Sephadex G-300 column. The enzymatic activity was 1.998 U/ml at 3.714 times, with 39.1%. The optimal pH for the partially purified pepsin was 3.0 and the optimal temperature for t pepsin activity was 35 Co and 5% of casein.

An 8-week feeding trial was conducted to evaluate the effects of oral administration of the probiotic yeast Rhodotorula sp. H26 in combination with Metschnikowia sp. C14 on the growth, digestive enzyme activity, body composition, immunity, and intestinal microbiota in the juvenile sea cucumber, Apostichopus japonicus. Sea cucumbers were distributed into four groups and received one of the following diets: BD) basal diet; H) BD + H26; C) BD + C14; or HC) BD + H26 + C14. After 4–8 weeks of feeding, sea cucumbers that were fed with the HC diet showed a significant increase in specific growth rate, pepsin, trypsin, amylase, and lipase activities compared with the BD diet group and/or single probiotic yeast s1 s0. H26 or C14) groups (P

Protein is the most costly nutrient in fish feed, and while diets offered in the early stages of development typically have high levels of CP, they do not always correspond to the real requirements of the animals. Thus, research that seeks to learn the true nutritional requirements of fish is fundamental to improving commercial fish culture. The present study evaluated the protein requirements of Nile tilapia (Oreochromis niloticus) under larviculture. Fish performance, gene expression for digestive enzymes and their enzymatic activity and stress response to air exposure were analyzed. Four experimental diets differing in CP level were formulated: 30%, 36%, 42% and 48%. Fish larvae were fed the experimental diets during development and sampled 10, 20 and 30 days after the beginning of the experiment for performance, gene expression and enzymatic activity. At sampling time 30, stress resistance was also evaluated by means of an air exposure test. At sampling time 10, CP levels between 36% and 48% could be used for a better performance. During this period, pepsinogen expression was greater for 30% CP, intermediate for 42% and lower for 36% and 48%. After this initial period, diets of between 30% and 42% CP are recommended for better performance. At sampling time 20, gene expression for digestive enzymes and their enzymatic activity were similar for all diets tested. At sampling time 30, the diet of 42% CP induced both greater pepsinogen expression and pepsin activity. Survival after the air exposure test after 30 days of feeding was influenced by CP level in the diet, with the highest survival being for fish fed with 36% CP. Taken together, the present results demonstrate that dietary CP influences digestive enzyme gene expression and activity, and suggest that the best CP levels for Nile tilapia larviculture vary depending on larval stage.

Despite great genetic diversity, sorghum grain consistently suffers from poor protein digestibility. The physicochemical packaging of protein bodies which consist of protease-resistant β- and γ-kafirin is considered a major obstacle. A synthetic β-kafirin gene, which shares the endosperm-specific promoter and signal peptide with the native β-kafirin gene (Sobic.009G001600.1), was transformed into sorghum inbred line Tx430. The gene was modified with ten additional proteolytic sites. These sites were designed to be amenable to cleavage by pepsin and/or chymotrypsin proteinases. Five independent transgenic lines were regenerated by microprojectile transformation. Notably, considerably more protein was observed in the peripheral endosperm of transgenic lines under scanning electron microscopy. Microscopy revealed invaginated or irregularly shaped protein bodies in the endosperm of transgenic lines. Grains of transgenic lines contained 11–37% more protein, which was 11–21% more pepsin digestible and 7–25% more chymotrypsin digestible than Tx430. Additionally, the abundant synthetic β-kafirin protein (5.6% of total protein) was detected by mass spectrometry data analysis in the transgenic line 9-1. Field-grown homozygous transgenics retained higher protein content, larger seed size and no reduction in grain number per plant. The results illustrated that plant synthetic biology could play an important role in improving sorghum nutritional value.

The interaction of nanoparticles (NPs) with proteins in their surroundings is a key factor determining their biological fate. The formation of a protein corona around ingested NPs in complex food matrices and in the gastrointestinal tract (GIT) is known to impact their gastrointestinal fate. In this study, the interaction between titanium dioxide (TiO2) NPs from a common food additive (E171) and casein, an abundant milk protein was characterized. The impact of these interactions on the potential gastrointestinal fate of the NPs was examined using a simulated GIT model. Our results showed that a series of complex molecular events occurred when the TiO2 NPs were added to casein solutions, including dissociation of casein micelles, NP-protein complex formation, and complex aggregation. Extensive aggregation was observed under conditions where charge neutralization occurred, which was attributed to a reduction in the electrostatic repulsion between the NP-protein complexes and to a polymer bridging effects. There was a pronounced decrease in the rate and extent of gastric digestion of the casein in the presence of the TiO2 NPs, indicating that complex formation reduced the access of pepsin to the peptide bonds. These findings stress the importance of taking into account the interactions of ingested NPs with food matrix and gastrointestinal components. Moreover, our findings show that the simple concept of a protein corona does not adequately explain the complex structural changes that occur when proteins and NPs interact.

The effects of hydrogen peroxide (H2O2) pretreatments and pepsin hydrolysis strategies on the extraction of pepsin-solubilized collagen (PSC) from the skin of snakehead (Channa argus) were studied. The dependences of H2O2 bleaching on H2O2 concentrations (1%, 3%, and 6% (w/v)) and pH (6, 8, and 10) were examined, while the difference between the conventional and unconventional pepsin hydrolysis methods was compared. Results showed that the yield of snakehead skin PSC was highly dependent on the parameters of both H2O2 pretreatments and pepsin hydrolysis processes. The color of PSC was affected by pH more greatly than by H2O2 concentration. Compared with the conventional pepsin hydrolysis of fish skins, the use of pepsin after extraction of acid-solubilized collagen (ASC) could improve the color of PSC. Moreover, the electrophoretic study, infrared spectroscopy, and fibril formation measurement showed that the structural integrity of PSC was largely influenced by the pH of H2O2 pretreatments, suggesting that the H2O2 solution (3% (w/v), pH 10) was suitable for the bleaching of snakehead skins. Finally, the amino acid analysis, ultraviolet spectroscopy, and differential scanning calorimetry confirmed that the prepared collagen had high purity and thermal stability. The light-color collagen might be used as an alternative for mammalian collagens.

Early identification of gastric precancerous lesions, including atrophic gastritis (AG) and intestinal metaplasia (IM), may improve gastric cancer detection and prevention. Because AG and IM are generally asymptomatic, many of the estimated 15 million Americans who carry these lesions remain undiagnosed.1 AG and IM are associated with either active or prior Helicobacter pylori (Hp) infection. Hp infection leads to perturbations in the serum concentration of gastric hormones pepsinogen I (PGI), pepsinogen II, the pepsinogen I/II ratio (PGR), gastrin-17 (G-17), and Hp IgG.2,3 In East Asia and other regions with high burden of Hp infection and gastric cancer, these biomarkers have been used as screening tools for AG and IM.4 However, there exists limited data on the sensitivity and discrimination of these serologic markers in low-Hp-prevalence populations, such as the United States.

In recent years, plant-based milk alternatives have become increasingly desirable because of their sustainability and proposed health benefits. There is a need to understand the behavior of plant-based milks during gastric digestion, including protein digestibility, structural changes, and macronutrient accessibility. The aim of this study was to investigate the gastric digestive behaviors of oat milk and an oat milk‒bovine skim milk blend (1:1, v/v), using an in vitro dynamic human gastric simulator. During gastric digestion with pepsin, the oat milk did not show significant changes in structure and physical stability. In contrast, the oat milk‒bovine skim milk blend formed coagulated, curd-like particles, which were induced by the action of pepsin on the milk proteins. The oat oil bodies were incorporated into the curd particles. This difference in gastric digestive behavior significantly altered the rate of gastric emptying. Coagulation of the oat milk‒bovine skim milk blend slowed the gastric emptying of macronutrients, leading to a delay in the release of protein and lipids into the small intestine compared with the oat milk. This study provides insight into the way the food structure modification during gastric digestion impacts nutrient delivery.

In this study, the impacts of various illumination intensities on growth, digestion and metabolism as well as antioxidant enzyme dynamics of Takifugu rubripes (0.03 ± 0.01 g) were investigated. Activities of alkaline phosphatase (AKP), acid phosphatase (ACP), pepsin (PPS), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC) were measured. Juveniles were reared under four degrees of illumination intensities: 50 mW/m2, 250 mW/m2, 500 mW/m2 and 750 mW/m2, at a constant photoperiod (12D:12 L). Samples were collected at days 7, 14, 21, 28, and 35. After 35 days, the 750 mW/m2 light intensity was found to have significantly increased the final body weight, which was 1.1 ± 0.005 g. On day 35, PPS activities of T. rubripes juveniles in the 750 mW/m2 sample group were significantly low when compared to those of the 250 mW/m2 group while AKP activities in the 750 mW/m2 group were significantly higher than those of the 50 and 500 mW/m2 groups (p 0.05). Even though they were relatively lower, there were no significant differences in SOD activities in the 250 mW/m2 group relative to the 500 and 750 mW/m2 groups. On day 35, high light intensity (750 mW/m2) resulted in stress responses that were characterized by T-AOC activities, and activity values were significantly lower than those of other groups (p

Cow milk allergy is a major cause of food hypersensitivity in infants and children. However, to the best of our knowledge, there has been minimal research on the antigenicity of cow milk (CM). As it is currently unknown if enzymatically hydrolyzed cow milk (HM) induces severe immunogenic responses, the potential allergenicity of HM was systematically evaluated in this work. HM effectively attenuated symptoms of weight loss and diarrhea, suppressed levels of mast cell tryptase, and relieved allergic inflammation of the intestine. Moreover, HM reduced the B220+ cell count in mouse blood. In addition, in vitro studies demonstrated that gastrointestinal digestion of HM was not resistant to pepsin or trypsin. Thus, HM effectively alleviated allergic reactions and exhibited lower potential allergenicity. These results provide practical information for the future development of hypoallergenic CM products.