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Enzymatic hydrolysis of dairy proteins is aimed to increase their nutritional value and reduce their allergenic properties. It is relevant to study the effects of enzymatic hydrolysis with highly active endopeptidase alсalase on the bioactivity of the whey and colostrum protein components. Dairy hydrolysates with various degree of Alcalase treatment were obtained in the present study. A comparative analysis of cleaved dairy proteins and their peptide fractions with a 5 and 10 kDa cutoff was performed. The protein and peptide composition of hydrolysates was determined using various techniques. The bioactivity of hydrolyzed whey and colostrum samples were estimated. The antioxidant activity of hydrolyzed and fractionated (5 kDa cutoff) whey samples increased by 5.91/6.62-fold and that of colostrum by 14.22/7.24-fold in fluorimetric/spectrophotometric assay, respectively. A significant decrease in the antigenic potential of milk peptides was observed with increasing degree of hydrolysis and subsequent ultrafiltration. Thus, bioactive dairy protein hydrolysates were obtained, which are applicable as a component of specialized foods with proven hypoallergenic properties and high antioxidant activity.

The influence of high‐pressure homogenisation (HPH) at 100 MPa on Lacticaseibacillus paracasei 90 (L90) was studied in vitro and in situ (fermented milk and cheese). Lysis and injury signs were observed in cells treated with HPH, which were linked to the release of intracellular enzymes and changes in the metabolic activity of L90. HPH treatment led to a higher lactic acid content and lower pH and pyruvic acid levels in fermented milk. The microbiological and peptide profiles of cheeses were modified by using cells or cell‐free extracts of L90. Finally, this study suggests that L90 could release bioactive peptides. [ABSTRACT FROM AUTHOR]

Cheese produced from fresh, stored or heat pretreated (65°C for 15 s) milk subjected to pasteurisation (72°C or 77°C for 15 s) was studied for chemical characteristics and proteolysis after 4 and 21 days of storage. Antioxidant activity was higher in cheese from fresh milk than in cheese from stored and heat pretreated milk. Malondialdehyde content as an index of lipid oxidation increased in cheese made with pretreated and preserved milk than in cheese made with fresh milk. Antioxidant activity and lipid oxidation were not significantly affected by pasteurisation temperature. Proteolysis increased during cheese maturation regardless of milk heat treatments. [ABSTRACT FROM AUTHOR]

ABSTRACT: Milk protein concentrate was hydrolyzed using one-step enzymatic hydrolysis. Both the peptide profiles and antioxidant activities of the resulting extensive hydrolysates of milk protein concentrate (EMPH) were analyzed using a peptidomics approach based on liquid chromatography–tandem mass spectrometry. The results demonstrated that the degrees of hydrolysis of the 4 EMPH by Alcalase-Protamex, Alcalase-Protease A 2SD, Alcalase-Flavorzyme, and Alcalase-ProteAXH were 12.02%, 16.85%, 15.87%, and 15.77%, respectively. Using size exclusion chromatography, 99.85% of the peptides in the Alcalase-Protease A 2SD hydrolysate were shown to have a molecular weight of

The impact of whey protein (WP) denaturation on the in vitro digestibility and biological activity of milk protein concentrate-85 (MPC85) was investigated. MPC85S1 and MPC85S2 having undenatured WP levels equal to 16.6 and 6.0 g/100 g overall protein, respectively, had similar in vitro protein digestibility corrected amino acid scores equal to 1.14. The samples were subjected to in vitro simulated gastrointestinal digestion while sampling was performed every 30 min during gastric (GD) followed by intestinal (GID) digestion. Liquid chromatography–mass spectroscopy showed that MPC85S1-GD, MPC85S2-GD, MPC85S1-GID and MPC85S2-GID had 50, 38, 47 and 66 unique peptides, respectively. The degree of hydrolysis, molecular mass distribution, dipeptidyl peptidase-IV inhibition, oxygen radical absorbance capacity and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity of the digests were compared. Overall, the results showed higher digestibility and bioactivities for low-denatured MPC85 compared to high-denatured MPC85 upon GD, however, following GID, both samples were digested to a similar extent.

This present study aimed to investigate the effects of various cooking times (1 h, 1.5 h, 2 h, 2.5 h, named as JHBP-1, JHBP-1.5, JHBP-2, JHBP-2.5) on the antioxidant activity and peptide profile of Jinhua ham broth peptides (JHBP). The peptides extracted from uncooked ham were used as an uncooked group with the name of JHBP-0. The results revealed that the antioxidant efficacy in the four cooked groups changed dramatically compared to JHBP-0. After cooking, the DPPH radical scavenging activity, hydroxyl radical scavenging activity and superoxide anion radical scavenging activity decreased, except for the Fe2+ chelation and ABTS+ scavenging capacity which increased significantly. However, the cooked groups still showed a strong antioxidant capacity. In particular, the superoxide anion radical scavenging ability and the Fe2+ chelation action were significantly stronger compared to glutathione (GSH) and butylated hydroxytoluene (BHT) (p < 0.05). JHBP-1.5 also displayed stronger antioxidant capacity than the other three cooked groups, and its secondary structure and mass distribution changed significantly after cooking, specifically with an increased proportion of helix and <1 kDa peptides. Moreover, the constitution of free amino acids (FAAs) and the types of peptides released in the broth increased significantly with a longer cooking time. In total, 1306 (JHBP-0), 1352 (JHBP-1), 1431 (JHBP-1.5), 1500 (JHBP-2), and 1556 (JHBP-2.5) peptide sequences were detected using LC-MC/MC. The proportion of <1 kDa peptides also gradually increased as the cooking time extended, which is consistent with the molecular weight distribution measurements. [ABSTRACT FROM AUTHOR]

The demand for plant-based meat analogs (PBMA) is on the rise as a strategy to sustain the food protein supply while mitigating environmental change. In addition to supplying essential amino acids and energy, food proteins are known sources of bioactive peptides. Whether protein in PBMA affords similar peptide profiles and bioactivities as real meat remains largely unknown. The purpose of this study was to investigate the gastrointestinal digestion fate of beef and PBMA proteins with a special focus on their potential as precursors of bioactive peptides. Results showed that PBMA protein showed inferior digestibility than that in beef. However, PBMA hydrolysates possessed a comparable amino acid profile to that of beef. A total of 37, 2420 and 2021 peptides were identified in the gastrointestinal digests of beef, Beyond Meat and Impossible Meat, respectively. The astonishingly fewer peptides identified from beef digest is probably due to the near-full digestion of beef proteins. Almost all peptides in Impossible Meat digest were from soy, whereas 81%, 14% and 5% of peptides in Beyond Meat digest were derived from pea, rice and mung proteins, respectively. Peptides in PBMA digests were predicted to exert a wide range of regulatory roles and were shown to have ACE inhibitory, antioxidant and anti-inflammatory activities, supporting the potential of PBMA as a source of bioactive peptides. [ABSTRACT FROM AUTHOR]

Milk protein concentrate was hydrolyzed using one-step enzymatic hydrolysis. Both the peptide profiles and antioxidant activities of the resulting extensive hydrolysates of milk protein concentrate (EMPH) were analyzed using a peptidomics approach based on liquid chromatography–tandem mass spectrometry. The results demonstrated that the degrees of hydrolysis of the 4 EMPH by Alcalase-Protamex, Alcalase-Protease A 2SD, Alcalase-Flavorzyme, and Alcalase-ProteAXH were 12.02%, 16.85%, 15.87%, and 15.77%, respectively. Using size exclusion chromatography, 99.85% of the peptides in the Alcalase-Protease A 2SD hydrolysate were shown to have a molecular weight of <3 kDa. A total of 33 common peptides were identified in the EMPH by liquid chromatography–tandem mass spectrometry, 16 of which were identified as bioactive peptides using bioinformatics. The peptide profiles and the coverage of master proteins of the 4 EMPH were different. The EMPH also exhibited strong free radical scavenging capacity, as indicated by the results of the 1,1-diphenyl-2-picrylhydrazyl radical, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), hydroxyl radical, and reducing power assays. The results of this study provided useful information on the peptide profiles and antioxidant activity of EMPH. [ABSTRACT FROM AUTHOR]

BackgroundDegenerative mitral valve disease is a common heart problem in dogs. The aims are to evaluate the relationships between right and left ventricular function, and blood lactate concentrations, assess prognostic contribution, and investigate whether serum peptidomics profile could reveal markers or determine the stage in dogs with valve degeneration.Materials and MethodsNinety-three dogs were evaluated in this study. Thirty-nine dogs' serum was collected and analyzed using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The Kaplan–Meier curve was used to predict the outcomes of mitral valve disease. Follow-up was obtained by a questionnaire or telephone to determine a survival time.ResultsThe BUN/creatinine ratio, vertebral heart score, and left atrium/aorta ratio were the independent predictors of cardiac mortality. Right ventricular systolic dysfunction was found in 50% of dogs with mitral valve disease. Dogs with right ventricular dysfunction had a significantly higher incidence of lower fractional shortening and larger right ventricular dimensions. The occurrence of right-sided dysfunction is proportionate to age and the degree of left ventricular dysfunction. High blood lactate concentrations were investigated in dogs with mitral valve disease stage C compared with stage B. The peptides such as mitogen-activated protein kinase, kallikrein, and tenascin-C appeared in the heart disease progression group.ConclusionRight-hearted function assessment, blood lactate levels, and peptidomics analysis may help early detection and prognosis of this disease in dogs. Peptidomics profiles from this study demonstrate the possibility for prognosis indicators of heart valve degeneration.

The demand for plant-based meat analogs (PBMA) is on the rise as a strategy to sustain the food protein supply while mitigating environmental change. In addition to supplying essential amino acids and energy, food proteins are known sources of bioactive peptides. Whether protein in PBMA affords similar peptide profiles and bioactivities as real meat remains largely unknown. The purpose of this study was to investigate the gastrointestinal digestion fate of beef and PBMA proteins with a special focus on their potential as precursors of bioactive peptides. Results showed that PBMA protein showed inferior digestibility than that in beef. However, PBMA hydrolysates possessed a comparable amino acid profile to that of beef. A total of 37, 2420 and 2021 peptides were identified in the gastrointestinal digests of beef, Beyond Meat and Impossible Meat, respectively. The astonishingly fewer peptides identified from beef digest is probably due to the near-full digestion of beef proteins. Almost all peptides in Impossible Meat digest were from soy, whereas 81%, 14% and 5% of peptides in Beyond Meat digest were derived from pea, rice and mung proteins, respectively. Peptides in PBMA digests were predicted to exert a wide range of regulatory roles and were shown to have ACE inhibitory, antioxidant and anti-inflammatory activities, supporting the potential of PBMA as a source of bioactive peptides.

This present study aimed to investigate the effects of various cooking times (1 h, 1.5 h, 2 h, 2.5 h, named as JHBP-1, JHBP-1.5, JHBP-2, JHBP-2.5) on the antioxidant activity and peptide profile of Jinhua ham broth peptides (JHBP). The peptides extracted from uncooked ham were used as an uncooked group with the name of JHBP-0. The results revealed that the antioxidant efficacy in the four cooked groups changed dramatically compared to JHBP-0. After cooking, the DPPH radical scavenging activity, hydroxyl radical scavenging activity and superoxide anion radical scavenging activity decreased, except for the Fe2+ chelation and ABTS+ scavenging capacity which increased significantly. However, the cooked groups still showed a strong antioxidant capacity. In particular, the superoxide anion radical scavenging ability and the Fe2+ chelation action were significantly stronger compared to glutathione (GSH) and butylated hydroxytoluene (BHT) (p < 0.05). JHBP-1.5 also displayed stronger antioxidant capacity than the other three cooked groups, and its secondary structure and mass distribution changed significantly after cooking, specifically with an increased proportion of helix and

The performances of protein hydrolysates highly depend on their peptide composition (amount, size and diversity), which itself closely depends on raw material origin and the hydrolysis parameters of the manufacturing process. The current analyses that characterize protein hydrolysates provide information on the level of hydrolysis (degree of hydrolysis, DH). However, they need additional describers to better characterize peptide profiles and product standardization. To reach this objective, we developed a fast and standardized method to characterize the abundance and the diversity of low-molecular-weight peptides in protein hydrolysates. This method innovatively combines classical HPSEC and nLC-ESI-MS analytical tools to characterize any kind of hydrolysate, whether solid or liquid, in terms of peptide level and diversity, and then merge peptides into 2D diagrams to visualize comparisons between protein hydrolysates. The targeted applications of this new tool for characterizing complex protein hydrolysates are (i) verifying the standardization of the produced products across batches, and (ii) analyzing and understanding the consequences of the modifications of the hydrolysis process on the molecular profiles of the generated peptides. The sample standardization described in this study is therefore an essential prerequisite for the functional characterization of hydrolysates in vitro.

The peptide profile, the angiotensin converting enzyme-inhibitory activity (ACE-IA) and the antioxidant property are important characteristics of protein hydrolysates and this was the first time the correlation among these parameters was investigated. Twenty-four hydrolysates from whey protein concentrate were prepared using four enzymes. With respect to the antioxidant activity, when using the B. licheniformis protease, a positive and significant correlation of strong intensity was observed with the contents of di- and tripeptides and medium peptides. Also, a negative and significant correlation of strong intensity was observed with the large peptide content. For the A. sojae protease and pancreatin, a positive and significant correlation of strong intensity was observed with the contents of di-and tripeptides. For the A. sojae protease, a negative and significant correlation of strong intensity was observed with the large peptide content. Concerning the ACE-IA, for the B. licheniformis and A. sojae proteases and pancreatin, a positive and significant correlation of strong intensity was observed with the contents of di-and tripeptides and medium peptides. For the A. sojae protease and pancreatin, this same kind of correlation was observed with the free amino acid content. For the B. licheniformis, A. sojae and A. oryzae proteases and pancreatin, a negative and significant correlation of strong intensity was observed with the large peptide content.

This paper shows the potential of dual enzyme approach on antioxidant activity of casein hydrolysates. Casein was hydrolysed using the proteolytic enzymes alcalase, flavourzyme in isolation and in sequential order. Casein hydrolysates were evaluated for the degree of hydrolysis, antioxidant activity, molecular weight distribution patterns and peptide sequence. Casein hydrolysate produced by the sequential hydrolysis of alcalase and flavourzyme showed higher degree of hydrolysis and antioxidant activity as compared to hydrolysate obtained by individual enzymes. In size exclusion chromatograph of casein hydrolysate S3, peptides with molecular weight of 0.57 kDa share 12% area in total area of chromatogram which was 10 times higher than that of hydrolysate S1 and nearly half of that of hydrolysate S2. On subjecting to HPLC-TOF-ESI separation potential antioxidant peptides were identified. The peptide sequence VLPVPQ along with potential fragments was identified in hydrolysate S1 and S2 and HPHPHLS along with its potential sequence was identified in hydrolysate S1, S2 and S3. Sequential hydrolysis of casein showed better antioxidant activity and peptide profile in less duration as compared to the casein hydrolysate obtained by individual enzyme. [ABSTRACT FROM AUTHOR]

Research on the effects of various antimicrobial agents on the strain Lactobacillus reuteri LR1 indicated its susceptibility to lincomycin, amoxicillin, and chloramphenicol, as well as resistance to other studied antibiotics. Upon milk fermentation by L. reuteri LR1 for 24 h, there was a significant increase in antioxidant and ACE-inhibitory activities, along with a decrease in L-leucine equivalents, as compared to the original milk. Further cultivation resulted in an increase in the inhibitory activity of the proteolytic, antioxidant, and angiotensin-converting enzyme (ACE), reaching its highest value after 96 h. HPLC-MS/MS analysis of the peptide profile of milk fermented by the lactobacillus showed the presence of peptides possessing ACE-inhibitory, antimicrobial, antioxidant, and immunomodulatory activities. Analysis of the substrate specificity of specificity of L. reuteri LR1 CEP proteinase toward the (f1-23) αs1-casein fragment revealed its unique specificity, which may indicate the PI/PIII type. [ABSTRACT FROM AUTHOR]

[Display omitted] • The digestibility of proteins in camel milk powder was higher than those of bovine milk powder. • Camel milk powder β-CN exhibited higher peptide coverage than bovine milk powder. • Anti-inflammatory peptide KVLPVPQ displayed the highest abundance in camel milk. This study aims to analyze the differences in digestion properties and peptide profiles between the skim camel and bovine milk powder after static in vitro simulated infant gastrointestinal digestion. The hydrolysis degree of camel milk proteins exceeded by 13.18% that of bovine milk. The concentration and release rate of free amino groups in the camel milk digesta was higher than that of bovine milk powder, which was likely due to the higher β-/α s -casein ratio and larger casein micelle size in camel milk. Camel milk powder presented higher β-CN coverage and comparatively shorter bioactive peptides compared to bovine milk powder. The anti-inflammatory peptide KVLPVPQ displayed the highest abundance in camel milk powder. Outcomes of this study showed that camel milk proteins possessed superior digestibility and unique peptides, which outlined the potential nutritional implications of camel milk for infants. [ABSTRACT FROM AUTHOR]

The chemical and biological characterization of peptide and protein components of the paralyzing venom from three Pompilidae solitary spider wasps (Pepsis mexicana, Pepsis terminata , and Anoplius nigritus) is described for the first time. The molecular masses of the most abundant peptides were determined. The N-terminal sequences of two cysteine-rich peptides were obtained from Pepsis. Metalloproteinase and hyaluronidase activities were identified in the venom of P. mexicana. A novel non-lethal method to collect venom is described. • The molecular characterization of venom from three Pompilidae is described for first time. • The peptide chromatographic profiles of the three species are different. • Peptides similar to Bradykinin or rich in cysteine were found. • P. mexicana venom presents metalloprotease and hyaluronidase activities. • A novel non-lethal method to collect spider wasp venom is described. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the effects of processing on the component interactions, the peptide profile as well as the bioactive peptides of preterm infant formula after digestion through EASY-nLC1200 Q Exactive Plus system. Results indicated that whey proteins and caseins transferred from serum and pellet fractions to fat fraction to recombine the milk fat globule membrane destroyed after homogenization. Protein interactions caused the changes of nitrogen distribution, protein profiles, and morphology after pasteurization and spray drying. Peptidomics analysis demonstrated that the component interactions of preterm infant formula affected the peptide profiles after digestion shown by the different peptide intensities of certain amino acid compositions and the totally different abundance of the peptides in heatmap. The hydrolysates of five groups exhibited 334, 274, 421, 214, and 265 unique peptides belonging to 144, 116, 185, 101, and 231 master accession proteins respectively. The top 8 abundant proteins identified were β-casein, Lipocln, α S1 -casein, α S2 -casein, κ-casein, bovine Glycosylation-dependent cell adhesion molecule, α-lactalbumin, and Albumin. The number of bioactive peptides increased after processing but were different from each other. In total, component interactions during processing of preterm infant formula could change the peptide profile and bioactive peptides after in vitro digestion. • Component interactions could occur during processing of preterm infant formula. • The component interactions could affect the profile and abundance of peptides after in vitro digestion. • Different unique peptides were identified of infant formula samples from different unit operations. • The number of bioactive peptides were also affected by component interactions. [ABSTRACT FROM AUTHOR]

Biologically active peptides with antioxidative, antibacterial, immunomodulating and other properties result from the reaction between the whey proteins and proteolytic enzymes of the gastrointestinal tract or purified proteases. This work aims to determine antimutagenic and antifungal effect of the enzymatic hydrolysate of whey protein obtained, to assess its acute toxicity characteristics and sensitizing power. Antimutagenic action of native whey proteins and hydrolysates (test sample and hydrolyzate analog) was assessed by the Ames test using indicator strains of Salmonella typhimurium ТА 98 and ТА 100. When determining the antifungal activity, opportunistic strains of Aspergillus niger and Candida albicans were used. The toxicity degree of samples was defined in studies to evaluate the acute intragastric toxicity in white rats as well as in the single abdominal dose study on the white mice. Irritating influence of whey proteins and peptides on was evaluated when applied to the eye mucosa of rabbits. The sensitizing capacity of samples was evaluated using the experimental model to reproduce the delayed hyperresponsiveness in white mice. It is identified that the developed hydrolisate is classified as the safe agent and has low sensitizing ability. The sample obtained has the comparative values of antioxidant and antimutagenic activity level as compared with the analog «Vital Аrmor H 801 LB» (Armor Proteines, France) used to manufacture functional products. The advantages of the hydrolisate developed include the increase in the content of peptide fraction and more pronounced antifungal activity towards A. niger .

The effect of addition of ripened cheese slurry into retentate on the proteolysis of Iranian ultrafiltered cheese was investigated during 60-day ripening. No significant differences were found in gross composition between experimental samples, however, pH values were significantly higher (P > 0.05) in slurry-containing cheese. Urea-polyacrylamide gel of the pH 4.6 insoluble fractions showed that αs1-casein was hydrolysed more rapidly than β-casein. There was no significant difference in the hydrolysis rate of αs1- and β-casein between the two cheeses. The levels of water soluble nitrogen were significantly higher (P > 0.05) in slurry-containing samples from day 15. The incorporation of ripened slurry into retentate influenced the peptide profiles obtained by RP-HPLC of the pH 4.6-soluble fractions of the cheeses. The ratio of hydrophilic to hydrophobic peptides was higher in slurry-containing cheese. Total and individual free amino acids were significantly higher (P > 0.05) in cheeses containing slurry. It was concluded that the incorporation of ripened cheese slurry into retentate has a beneficial effect on proteolysis acceleration and development of aroma and flavour in Iranian ultrafiltered white cheese.

The study aimed to analyze pH and heat treatment’s effect in modulating the release of peptides with antioxidant activity after simulated gastrointestinal (GI) digestion of Egg white powder (EWP). EWP samples with neutral (EWPN) and alkaline (EWPA) pH were heat-treated at 20, 60, and 90 °C and analyzed for protein aggregation, solubility, and GI digestibility. Heat treatment decreased solubility and induced protein aggregation, which was higher for EWPN as compared to EWPA. The unfolding of EWPA proteins at 60 °C exhibited a higher GI digestibility and antioxidant activity via Oxygen Radical Absorbance Capacity (ORAC) assay as compared to EWPN. Interestingly, a reverse trend was observed in the cellular antioxidant assay, and the GI-digest of EWPN exhibited a higher antioxidant activity. The LC-MS/MS analysis are in concordance with cellular antioxidant activity assay and showed a higher intensity for peptides with potential antioxidant activity in the GI-digest of EWPN. The results indicate that heat treatment but not the pH is a critical factor in improving the protein digestibility and releasing peptides with antioxidant activity after GI digestion.

An infant in vitro digestion model was utilized to investigate protein digestion characteristics in human and diverse mammalian milk (i.e., cow, goat, sheep, mare, and camel milk) using electrophoresis and chromatography. Digestive differences among milks were mainly manifested in the infant gastric phase, as evidenced by varying degrees of protein digestion. Notably, proteins (i.e., lactoferrin, serum albumin, and immunoglobulin G-heavy chain) remained partially intact in human milk, whereas these proteins in animal milk were exclusively degraded after gastrointestinal digestion. The peptide spectra of human, mare, and camel milk were highly similar, with a predominant formation of low-intensity small peptides, whereas the other three milk showed the opposite phenomenon. Heatmap cluster analysis indicated that camel milk was the most comparable to human milk before digestion, yet sheep milk was the most similar to human milk regarding protein digestion behaviors following infant gastric digestion.

The angiotensin‐converting enzyme (ACE)‐inhibitory activities, peptide profiles and organic acid contents in kefir produced by kefir grains plus lactic acid bacteria as adjunct cultures were determined. All the kefir samples showed almost similar peptide profiles as detected by RP‐HPLC, but quantitative differences were observed during storage. The ACE‐inhibitory activities of different lactic cultures did not exhibit a linear tendency during storage period. After 7 days of storage, there was a significant increase in ACE‐inhibitory activity of the sample fermented with Lactobacillus helveticus. However, a kefir sample containing Streptococcus thermophilus, Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis exhibited a higher ACE‐inhibitory activity (92.23%) compared to the other samples. [ABSTRACT FROM AUTHOR]

In the present study, the antipyretic activity of Bubali Cornu (water buffalo horn) fraction and its metabolomics were investigated. The fraction decreased rat rectal temperature, and 13 endogenous metabolites were identified as potential biomarkers. Selected metabolites were involved in arachidonic acid metabolism and glycerophospholipid metabolism etc. Following treatment with the fraction, four metabolites, pyroglutamic acid, palmitelaidic acid, leukotriene A4, and prostaglandin A2 were reversed. In addition, the levels of interleukin-1β, tumor necrosis factor-α, prostaglandin E2, and cyclic adenosine monophosphate in plasma were also reversed after treatment as determined by enzyme linked immunosorbent assay. Furthermore, nano-flow liquid chromatography with orbitrap mass spectrometry detection was used to analyze the peptides in the fraction. In total, 824 peptide sequences mainly from keratins were determined, with Keratin 14, Keratin 34, and Keratin 86 representing the three main types of keratin hydrolysis in water buffalo horn based on peptide heat maps. Of the identified peptides, 81.2% were hydrophilic and the molecular weight of 70.3% of identified peptides was lower than 2000 Da. According to the metabolomics- and peptidomics-based approach used in the present study, it is feasible to identify and analyze the active peptide matrix from animal-horn-derived traditional Chinese medicines. [ABSTRACT FROM AUTHOR]

[Display omitted] • Denaturation of milk protein concentrate-85 (MPC85) did not change PDCAAS value. • The peptide profile of MPC85 changed with whey protein (WP) denaturation level. • Low denatured MPC85 had higher digestibility and bioactivity upon gastric digestion. • Subjection of MPC85 to gastrointestinal digestion released many peptides <1 kDa. The impact of whey protein (WP) denaturation on the in vitro digestibility and biological activity of milk protein concentrate-85 (MPC85) was investigated. MPC85S1 and MPC85S2 having undenatured WP levels equal to 16.6 and 6.0 g/100 g overall protein, respectively, had similar in vitro protein digestibility corrected amino acid scores equal to 1.14. The samples were subjected to in vitro simulated gastrointestinal digestion while sampling was performed every 30 min during gastric (GD) followed by intestinal (GID) digestion. Liquid chromatography–mass spectroscopy showed that MPC85S1-GD, MPC85S2-GD, MPC85S1-GID and MPC85S2-GID had 50, 38, 47 and 66 unique peptides, respectively. The degree of hydrolysis, molecular mass distribution, dipeptidyl peptidase-IV inhibition, oxygen radical absorbance capacity and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity of the digests were compared. Overall, the results showed higher digestibility and bioactivities for low-denatured MPC85 compared to high-denatured MPC85 upon GD, however, following GID, both samples were digested to a similar extent. [ABSTRACT FROM AUTHOR]

The aim of this study was to prepare enzymatic hydrolysates from whey protein concentrate with a nutritionally adequate peptide profile and the ability to inhibit angiotensin-converting enzyme (ACE) activity. The effects of the type of enzyme used (pancreatin or papain), the enzyme:substrate ratio (E:S ratio=0.5:100, 1:100, 2:100 and 3:100) and the use of ultrafiltration (UF) were investigated. The fractionation of peptides was performed by size-exclusion-HPLC, and the quantification of the components of the chromatographic fractions was carried out by a rapid Corrected Fraction Area method. The ACE inhibitory activity (ACE-IA) was determined by Reverse Phase-HPLC. All parameters tested affected both the peptide profile and the ACE-IA. The best peptide profile was achieved for the hydrolysates obtained with papain, whereas pancreatin was more advantageous in terms of ACE-IA. The beneficial effect of using a lower E:S ratio on the peptide profile and ACE-IA was observed for both enzymes depending on the conditions used to prepare the hydrolysates. The beneficial effect of not using UF on the peptide profile was observed in some cases for pancreatin and papain. However, the absence of UF yielded greater ACE-IA only when using papain.O objetivo deste estudo foi preparar hidrolisados enzimáticos do concentrado proteico do soro de leite com perfil peptídico nutricionalmente adequado e com capacidade para inibir a atividade da enzima conversora da angiotensina (ECA). Os efeitos do tipo de enzima usado (pancreatina ou papaína), da relação enzima:substrato (E:S=0,5:100, 1:100, 2:100 e 3:100) e do uso da ultrafiltração (UF) foram investigados. O fracionamento dos peptídeos foi feito por CLAE de exclusão molecular e a quantificação dos componentes das frações cromatográficas foi realizada pelo método da Área Corrigida da Fração. A atividade inibitória da ECA (AI-ECA) foi determinada por CLAE de fase reversa. Todos os parâmetros testados afetaram tanto o perfil peptídico quanto a AI-ECA. O melhor perfil peptídico foi atingido para os hidrolisados obtidos com papaína, enquanto a pancreatina foi mais vantajosa em termos da AI-ECA. O efeito benéfico do uso de menor relação E:S sobre o perfil peptídico e a AI-ECA foi observado para ambas as enzimas dependendo das condições usadas para o preparo dos hidrolisados. O efeito benéfico da ausência da UF sobre o perfil peptídico foi observado em alguns casos para pancreatina e papaína. No entanto, a ausência da UF produziu maior AI-ECA somente quando a papaína foi usada.

Bioactive peptides, released from buttermilk by fermentation and/or gastrointestinal proteases, may have health promoting effects. Thus, a comprehensive analysis of the peptide fraction of fermented buttermilk, before and after different phases of simulated gastrointestinal digestion, was performed using ultra high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS). Results showed that digestion simulation substantially changed the peptide profile of fermented buttermilk. A total of 81, 120 and 46 peptides were identified in fermented buttermilk, its gastric and intestinal digests, respectively. These peptides released mostly from β-casein followed by αs1-casein, κ-casein and β-lactoglobulin. In addition, 14 peptides released from milk fat globule membrane proteins (lactadherin, butyrophilin and GlyCAM-1). Bioactivity, mainly angiotensin converting enzyme (ACE) inhibitory activity, has been reported before for only 54 of the detected peptides. Radical scavenging, ferric reducing and ACE inhibitory activities of fermented buttermilk peptides increased significantly after digestion, indicating promotion in fermented buttermilk-peptide bioactivity by gastrointestinal digestion. [Display omitted] • Fermented buttermilk contains a unique peptide profile. • Buttermilk peptides are released from both milk proteins and MFGM proteins. • Fermented buttermilk peptides have antioxidant and ACE inhibitory activities. • Both bioactivities increased significantly after gastrointestinal digestion. • Peptides released from fermented buttermilk may have specific biofunctionalities. [ABSTRACT FROM AUTHOR]

High salt (NaCl) consumption can impact on human health, and KCl is the most widely used replacement salt in meat products. This study investigated the effects of 0% NaCl (NS), 3% NaCl (HS), 1.95% NaCl (RS), 1.95% NaCl+1.05% KCl (RS + K) on protein digestibility of pork sausage in vitro. The results indicated that RS + K showed the highest gastrointestinal digestibility (GID) because of the structure of looser cross-linked strands and uniform cavities, while HS exhibited the lowest GID. RS + K released more peptides (2499) during gastrointestinal than NS (2301), RS (2130) and HS (2235), with a higher proportion of peptides with molecular weights <1000 Da, and more unique peptides. Meanwhile, the digestion product of RS + K exhibited excellent radical scavenging activity and improved the antioxidant abilities to reduce oxidative injury which was induced by H 2 O 2 in HepG2 cells. These results demonstrated that partial substitution with KCl can be an effective strategy for improving the digestibility of sodium-reduced gel-type meat products. • The pork sausage with partial substitution of NaCl by KCl (RS + K) exhibited an improved protein digestion. • RS + K exhibited the highest digestion and released the most peptides. • The digestion products of RS + K showed enhanced antioxidant activities in vitro. [ABSTRACT FROM AUTHOR]

Enzymatic hydrolysis of whey protein (WP) was carried out under pH-controlled and non pH-controlled conditions using papain and a microbial-derived alternative (papain-like activity). The impact of such conditions on physicochemical and bioactive properties was assessed. WP hydrolysates (WPH) generated with the same enzyme displayed similar degree of hydrolysis. However, their reverse-phase liquid chromatograph mass spectrometry peptide profiles differed. A significantly higher oxygen radical absorbance capacity (ORAC) value was obtained for WP hydrolysed with papain at constant pH of 7.0 compared to the associated WPH generated without pH regulation. In contrast, there was no significant effect of pH regulation on dipeptidyl peptidase IV (DPP-IV) properties. WP hydrolysed with papain-like activity under pH regulation at 7.0 displayed higher ORAC activity and DPP-IV inhibitory properties compared to the associated WPH generated without pH regulation. This study has demonstrated that pH conditions during WPH generation may impact on peptide release and therefore on WPH bioactive properties. [ABSTRACT FROM AUTHOR]

The effect of addition of ripened cheese slurry into retentate on the proteolysis of Iranian ultrafiltered cheese was investigated during 60-day ripening. No significant differences were found in gross composition between experimental samples, however, pH values were significantly higher (P > 0.05) in slurry-containing cheese. Urea-polyacrylamide gel of the pH 4.6 insoluble fractions showed that αs1-casein was hydrolysed more rapidly than β-casein. There was no significant difference in the hydrolysis rate of αs1- and β-casein between the two cheeses. The levels of water soluble nitrogen were significantly higher (P > 0.05) in slurry-containing samples from day 15. The incorporation of ripened slurry into retentate influenced the peptide profiles obtained by RP-HPLC of the pH 4.6-soluble fractions of the cheeses. The ratio of hydrophilic to hydrophobic peptides was higher in slurry-containing cheese. Total and individual free amino acids were significantly higher (P > 0.05) in cheeses containing slurry. It was concluded that the incorporation of ripened cheese slurry into retentate has a beneficial effect on proteolysis acceleration and development of aroma and flavour in Iranian ultrafiltered white cheese. [ABSTRACT FROM AUTHOR]

[Display omitted] • The latest discovery on the digestive properties and peptide profile of rubing cheese. • Rubing cheese peptides exhibited antioxidant effect, ACE inhibition and α-glucosidase inhibitory. • Generation of potentially bioactive peptides is affected by acidification technology changes. • Fermentation-acidification improved digestibility and produce more bioactive peptides. Rubing cheese is a traditional Chinese Protected Designation of Origin (PDO) cheese consumed for more than six hundred years, but to date, the digestion properties and peptide profiling during simulated gastrointestinal digestion are still uncertain. This study aimed to investigate the effects of traditional direct acidification technology (TRB) and fermentation acidification technology on digestion properties and peptide profiling of rubing cheese (FRB) proteins after simulated gastrointestinal digestion by protein digestomics, coupled with bioinformatic in silico analyses to identify potential bioactive peptides. The results demonstrated that FRB could significantly improve the in vitro digestibility, protein degradation, and polypeptide content than TRB (P ＜ 0.05). Furthermore, a total of 369 and 332 peptides were identified in FRB- and TRB-pancreatic digests, respectively, using LC-MS/MS. FRB could release more low molecular weight peptides of 400–1200 Da from α -casein and β -casein after digestion. These low peptides included 16 reported potential ACEIPs (angiotensin I-converting enzyme inhibitory peptides), 11 dipeptidyl peptidase-IV (DPP-IV) inhibitory peptides, and 6 antioxidant peptides, while TRB contained more than the reported potential antimicrobial peptides (10). In vitro activity determination showed that FRB had significantly higher ACEI, α-glucosidase inhibitory, and antioxidant activities than TRB during the entire digestion time (P ＜ 0.05), which was correlated to the reported potential bioactive peptides released during the digestion of FRB. Our study is the most comprehensive protein digestomic analysis of Chinese rubing cheese to date and provides a new positive outlook on rubing cheese consumption. [ABSTRACT FROM AUTHOR]

• Steam-cooking induced more thorough hydrolysis but less oyster-derived peptides. • Two regions of Cra g 1 (residues 224–228 and 245–248) appeared to be digest-tolerant. • Six novel ACEi peptides were screened and identified from C. gigas hydrolysates. • Leu-Ser-Leu exhibited the best ACEi activity with a potential interaction to Zn2+. This study aimed to investigate the effect of steam cooking on the proteolysis of Pacific oysters (Crassostrea gigas) using the simulated oral-gastrointestinal digestion model and a NCM460 cell monolayer. Steam cooking changed the peptide profile of the digests of oysters considerably and induced more thorough hydrolysis. However, the heat-stable allergen, Cra g 1 , still had remnant fragments in the intestinal phase, which could be allergenic epitopes. Two regions of Cra g 1 (residues 224–228 and 245–248) were digestion-tolerant. Furthermore, more oligopeptides were derived from raw proteins than from steamed proteins. After molecular docking and in vitro determination, six novel angiotensin I-converting enzyme inhibitory (ACEi) peptides were finally identified in the hydrolysates (WIS, WLS, LSL, SGPF, LGPI, and IGLP). Among them, LSL exhibited the highest ACEi activity (IC 50 = 107.17 nM). Our findings provide supportive information on the effective utilization of oyster proteins. [ABSTRACT FROM AUTHOR]

Abstract: Enzymatic hydrolysates from chicken skin protein were investigated for their in vitro inhibitions of angiotensin converting enzyme (ACE) and renin activities. Enzyme hydrolysis of the chicken skin protein from the thigh and breast muscles was done using alcalase or a combination of pepsin/pancreatin (PP) at enzyme concentrations of 1–4%. The chicken skin protein hydrolysates (CSPH) were then fractionated by membrane ultrafiltration into different molecular weight peptides (<1, 1–3, 3–5 and 5–10kDa). Results showed that degree of hydrolysis (DH) of the hydrolysates increased significantly with protease concentration for all the samples (72.61–81.88%) and correlated positively with peptide yield. The alcalase hydrolysates generally had significantly higher (p<0.05) ACE-inhibitory activity when compared to PP hydrolysates. ACE inhibition was inversely related to size of ultrafiltration membrane peptides. A moderate renin-inhibitory activity was observed (15–36%), which was dependent on the type of protease; the PP hydrolysates showed significantly higher (p<0.05) inhibition than alcalase hydrolysates. These results suggest that CSPH can be considered a potential ingredient for the development of functional foods and nutraceuticals that can attenuate catalytic activities of ACE and renin. [Copyright &y& Elsevier]

In this work, the influence of some reactional parameters in the hydrolysis of whey protein concentrate (WPC) was evaluated, in terms of the nutritional quality of peptide profiles of the hydrolysates as well as the reduction of costs for scaling-up the process. Two enzymes (subtilisin and pancreatin) were used for preparing 18 hydrolysates, using different E:S ratios and reaction times, and the distribution of peptides according to chain length was analyzed by size-exclusion chromatography. The studied parameters affected the peptide profiles of WPC hydrolysates and the best result was similar for subtilisin and pancreatin, both using an E:S ratio of 4:100, after 5 h and 10 h, respectively. In these conditions, these enzymes gave rise to the smallest large peptide contents (12.28% and 12.34%, respectively) and one of the highest amount of di- and tripeptides (13.34% and 13.00%, respectively) as well as of free amino acids (45.56% and 47.26%, respectively). However, in terms of number of samples the action of pancreatin was more advantageous than subtilisin, since among the nine hydrolysates, four showed appropriate peptide profiles (P1, P2, P5, and P6), from the nutritional point of view, while the same happened only with one hydrolysate prepared by using subtilisin (S3). Also, the economical advantage of using smaller E:S ratio and reaction time was observed in several cases for both enzymes. [ABSTRACT FROM AUTHOR]

We applied in vitro models of gastrointestinal (GI) digestion simulating the conditions of the GI tract of healthy adults and elderly individuals with achlorhydria (EA) to investigate differences in the digestibility of meat (chicken, beef and pork) and soy proteins. Digestibility was significantly affected by EA alterations. Peptidomics analyses revealed significant differences in peptide profiles between control and EA conditions, including number, length distribution, clustering, and differentially abundant peptides (DAPs). Our results revealed that the differences in meat peptide profiles diminished going from the gastric to intestinal phase. For soy protein, the marked differences between control and EA conditions were maintained in the gastric and intestinal phases. Higher numbers of potentially bioactive peptides were generated under the control condition compared to the EA condition. The present study provides insight into the distinct peptide profiles generated by in vitro digestion of meat and soy proteins under adult and EA GI conditions., (Copyright © 2022. Published by Elsevier Ltd.)

Pathogenic variability studies in bean common mosaic virus (BCMV) infecting common bean (Phaseolus vulgaris L.) revealed the existence of two pathogroups PG-I and PG-II and four strains (NL-1, NL-1n, NL-7 and NL-7n) in Himachal Pradesh, a North-Western Himalayan state of India. Two strains, NL-1 and NL-7 were identical to the previously described NL-1 and NL-7 strains from Europe and USA, whereas the other two designated as NL-1n and NL-7n differed from earlier identified strains with respect to their necrotic reaction on cultivar Jubila at high temperature (4308C). Reverse phase HPLC peptide profiling of tryptic digests of coat protein of these strains further confirmed that NL-1, NL-1n, NL-7 and NL-7n are distinct from each other. This study constitutes the first record of pathogenic variability in BCMV infecting common bean in India. [ABSTRACT FROM AUTHOR]

The comparative characteristics are given of the organoleptic, physicochemical, and immunochemical properties of developed whey protein partial hydrolysates (Belarus), whey protein hydrolysate (Russia), and imported partial hydrolysates Vitalarmor H 801 LB (France), PRODIET GF 006 (France), and Hilmar 8350 (United States). It is established that the developed hydrolysate (Belarus) conforms to imported analogues used as a protein component for specialized and infant foods [ABSTRACT FROM AUTHOR]

Abstract: This work proposes, for the first time, the use of a high intensity ultrasonic probe to accelerate the tryptic digestion of soybean proteins. Different digestion parameters were optimized: protein extracting solution, reduction, and alkylation conditions (time, concentration, and temperature), trypsin:protein ratio, and ultrasonic conditions (sonication amplitude and time). Separation of peptide profiles was carried out by capillary-HPLC. The effect of the variation of chromatographic conditions (elution gradient, column temperature, and injection volume) on peptide separation was also studied using two capillary-HPLC columns with different column diameters and particle sizes. Moreover, samples were focused at the top of the column in order to obtain an increasing sensitivity without loss of efficiency. This method was successfully applied to the profiling of soybean peptides from transgenic and non-transgenic soybeans and from different pigmented beans commercialized as soybeans. [ABSTRACT FROM AUTHOR]