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The purpose of this paper is to understand the effect of hydrolysis by pepsin and pancreatin on the angiotensin-I-converting enzyme (ACE) inhibitory activity of bioactive peptide from pigeon pea tempe and the absorption of pigeon pea tempe peptide by using the everted gut sac method.

The tempe was prepared by inoculating Raprima (Rhizopus oligosporus) on hulled-cooked pigeon pea for 48 h. The extraction was performed using the ultrasonic method at 40 kHz frequency and 100% ultrasonic power for 10 min. The extracted protein was placed in simulated gastrointestinal digestion using consecutive pepsin–pancreatin for 240 min. The hydrolysates were fractionated using a dialysis tube, and its absorption was assessed using the everted Sprague–Dawley rat gut sac.

The tempe protein from the hydrolyzed pigeon pea exhibited higher ACE inhibitory (71.53%) activity than that from the boiled pigeon pea (53.04%) (p = 0.028). The bioactive peptide of the digested pigeon pea tempe consisted of low-molecular-weight peptides (<1 kDa). The fraction also showed the highest ACE inhibition activity among the others (IC50 = 0.61 mg/mL, p = 0.021). Bioactive peptides from pigeon pea tempe were absorbed well in the small intestine, mainly in the jejunum. The activity of the absorbed peptides did not change considerably.

The activity of bioactive peptide of pigeon pea tempe was comparatively stable during digestion. It exhibited activity even after absorption in the small intestine. Thus, pigeon pea tempe can serve as an antihypertensive peptide source and alternative food for maintaining/reducing blood pressure.

The aim of the article was to focus on various peptides identified in the egg and their probable application as novel ingredients in the development of functional food products. Bioactive peptides of egg origin have attracted increasing interest as one of the prominent candidates for development of various health-promoting functional and designer foods.

Traditionally known as a source of highly valuable proteins in human nutrition, eggs are nowadays also considered as an important source of many bioactive peptides which may find wide application in medicine and food production. These specific protein fragments from egg proteins which, above and beyond their nutritional capabilities, have a positive impact on the body’s function or condition by affecting the digestive, endocrine, cardiovascular, immune and nervous systems, and may ultimately influence health.

Several peptides that are released in vitro or in vivo from egg proteins have been attributed to different health effects, including antihypertensive effects, antimicrobial properties, antioxidant activities, anticancer activity, immunomodulating activity, antiadhesive properties and enhancement of nutrient absorption and/or bioavailability. Extensive research has been undertaken to identify and characterize these biologically active peptides of egg origin which has changed the image of egg as a new source of biologically active ingredients for the development of functional foods with specific benefits for human health and treatment and prevention of diseases.

The paper mainly describes the above-stated properties of bioactive peptides derived from egg proteins.

The purpose of this paper is to focus on the selection of the optimum porous material modified with poly-dopamine coating for peptides enrichment. The adsorption behaviors for peptides and the antioxidant capacity of peptides fraction purified by the porous materials were investigated.

The optimum porous material with the highest adsorption capacity for peptides was selected for surface modification. The surface modified porous material was characterized by SEM, nitrogen adsorption-desorption isotherm and color change.

The results showed that the porous material was successfully modified with poly-dopamine coating. Adsorption capacity for peptides of the modified porous material was enhanced compared to the original porous material. Antioxidant capacity of peptides fraction enriched by the modified porous material was much higher than that enriched by the original porous material, indicating that the introduction of poly-dopamine coating was inclined to enrich peptides with certain amino acid residues.

The structures of peptides are a bit not clear, which is the subject of future investigation.

This contribution provides a method to design and prepare porous materials with poly-dopamine coating to separate and enrich peptides or peptides fraction with high antioxidant capacity.

It showed that polarity, surface area, pore diameter and interactions were contributed to high adsorption capacity. The peptides fraction purified by the modified porous material showed excellent antioxidant capacity through results of reduction of DPPH radical, because of the enrichment of the peptides with certain amino acids residues which were considered to enhance radical scavenging capacity. This paper provides new insights into designing and preparing porous materials with poly-dopamine coating to enrich peptides fraction with high antioxidant capacity.

The aim of this research is the evaluation of the profile of peptides isolated from skim milk hydrolysates.

Five hydrolysates were prepared using a protease from Aspergillus Oryzae (AO) separately or in combination with papain (PA) in different reaction times. The hydrolysates were fractionated by size‐exclusion HPLC and the rapid method of correct fraction area (CFA) was used for quantifying the peptides and free amino acids in the chromatographic fractions. The nutritional quality of hydrolysates is directly related to their di‐ and tripeptide contents, several reports show that the amino acid provided by these peptides are more quickly and completely absorbed than those from intact protein.

The results showed a nutritional similarity of the isolated action of AO and its combinations with PA, considering the peptide patterns produced, giving rise to 16 percent of di‐ and tripetides. Increasing the reaction time of the two enzymes led to poorer peptide profiles, while no change was achieved when the reaction time of only one enzyme (AO) in the combination was enlarged. Other hydrolytic conditions could be tested in order to improve the peptide profile of skim milk hydrolysates.

The application of this study relates to the possibility of using these hydrolysates for preparing high nutritional formulation for dietetic purposes. The use of a technique allowing the fractionation of peptides according to their size as well as the use of the skim milk as protein source, instead of casein, which is very expensive in the developing countries, represents a novel approach.

Provides an evaluation of the profile of peptides isolated from skim milk hydrolysates.

A control of the first‐line human defence system, using mechanisms analogous to specific and non‐specific (parametric) triggering of phagocytosis, is proposed on the basis of an autocatalytic model of biphasic modulation of phagocyte luminescence by experimental peptide medicines. Properties of the autocatalytic model are described and its catastrophe and bifurcation sets determined. The mechanism analogous to parametric triggering is shown to result from a fold catastrophe produced by the changes in the autocatalytic interaction parameter characterising a given peptide preparation. Usefulness of the model was shown by its application to two distinct peptide preparations having different immunomodulatory properties.

Smart biosensors that can perform sensitive and selective monitoring of target analytes are tremendously valuable for trinitrotoluene (TNT) explosive detection. In this research, the pre-developed sensor was integrated with biological receptors in which they enhanced the sensitivity of the sensor. This is due to conjugated polydiacetylene onto a peptide-based molecular recognition element (Trp-His-Trp) for TNT molecules in graphene field-effect transistors (GR-FETs) as biosensor that is capable of responding to the presence of a TNT target with a colorimetric response. The authors confirmed the efficacy of the receptor while being attached to polydiacetylene (PDA) by observing the binding ability between the Trp-His-Trp and TNT to alter the electronic band structure of the PDA conjugated backbones. The purpose of this paper is to demonstrate a modular system capable of transducing small-molecule TNT binding into a detectable signal. The details of the real-time and selective TNT biosensor have been reported.

Following an introduction, this paper describes the way of fabrication GR-FETs with conventional photolithography techniques and the other processes, which is functionalized by the TNT peptide receptors. The authors first determined the essential TNT recognition elements from UV-visible spectrophotometry spectroscopy for PDA sensor unit fabrication. In particular, the blue percentage and the chromic response were used to characterize the polymerization parameter of the conjugated p backbone. A continuous-flow trace vapor source of nitroaromatics (two, four, six-TNT) was designed and evaluated in terms of temperature dependence. The TNT concentration was measured by liquid/gas extraction in acetonitrile using bubbling sequence. The sensor test is performed using a four-point probe and semiconductor analyzer. Finally, brief conclusions are drawn.

Because of their unique optical and stimuli-response properties, the polydiacetylene and peptide-based platforms have been explored as an alternative to complex mechanical and electrical sensing systems. Therefore, the authors have used GR-FETs with biological receptor-PDAs as a biosensor for achieving high sensitivity and selectivity that can detect explosive substances such as TNT. The transport property changed compared to that of the field-effect transistors made by intrinsic graphene, that is, the Dirac point position moved from positive Vg to negative Vg, indicating the transition of graphene from p-type to n-type after annealing in TNT, and when the device was tested from RT, the response of the device was found to increase linearly with increasing concentrations. Average shifting rate of the Dirac peak was obtained as 0.1-0.3 V/ppm. The resulting sensors exhibited at the limit ppm sensitivity toward TNT in real-time, with excellent selectivity over various similar aromatic compounds. The biological receptor coating may be useful for the development of sensitive and selective micro and nanoelectronic sensor devices for various other target analytes.

The detection of illegally transported explosives has become important as the global rise in terrorism subsequent to the events of September 11, 2001, and is at the forefront of current analytical problems. It is essential that a detection method has the selectivity to distinguish among compounds in a mixture of explosives. So, the authors are reporting a potential solution with the designing and manufacturing of electrochemical biosensor using polydiacetylene conjugated with peptide receptors coated on GR-FETs with the colorimetric response for real-time detection of TNT explosives specifically.

The hypocholesterolemic activity of legume vicilins and the structural homology among mung bean, soybean and adzuki bean vicilins (8S) suggest that this protein may play a role in lipid metabolism. Thus, in the present study, the authors aim to isolate the mung bean vicilin and assess its in vitro effect on 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG CoAr), the enzyme responsible for endogenous cholesterol synthesis.

Chromatographic and electrophoretic characterization identified the molecular mass and polypeptide composition of mung bean vicilin. The hydrolysate of this globulin was obtained by sequential hydrolysis with pepsin-pancreatin and the fragments were characterized by molecular filtration, SDS PAGE and HPLC.

The molecular mass of vicilin was estimated as 158.23 at ± 10 kDa and SDS-PAGE revealed that the 8S globulin protein comprises four bands corresponding to polypeptides of 61, 48, 29 and 26 kDa. Fractions 10, 12, 14, 22 and 32 of the eluate from Sephadex G-25 exhibited significant inhibition of HMG CoAr.

The correspondence of the chromatographic profile of the peptide fractions with hypocholesterolemic activity suggests that the composition and chemical structure of these peptides are essential to their physiological effectiveness. The beneficial effects of mung bean vicilin identified in this study will support the characterization of this protein as a functional compound.

The purpose of this study was to determine the effects of chickpea (Cicer arietinum) protein hydrolysates prepared at two degrees of hydrolysis (DH) on lipoprotein profile and on oxidant status in cholesterol-fed rats.

Eighteen male Wistar rats (220 ± 10 g) were divided into three groups and fed for 30 days a diet containing 20 per cent casein supplemented with 1 per cent cholesterol and 0.5 per cent cholic acid. During the experimentation, the first and the second groups received daily by gavage 250 mg of chickpea protein hydrolysates/rat at DH = 8 per cent (CPH8) and DH = 17 per cent (CPH17), respectively. The third group, named control group (CG), received water under the same conditions.

Serum total cholesterol concentrations were reduced in CPH8 (p < 0.0073) and CPH17 (p < 0.0004) groups versus CG. This reduction corresponded to a lower very-low-density lipoprotein (VLDL)-cholesterol (p < 0,0019). CPH17 reduced low-density lipoprotein- and high-density lipoprotein (HDL)-cholesterol (p < 0.0001) but increased apolipoprotein A4 (p < 0.002) concentrations and lecithin-cholesterol acyltransferase activity (p < 0.0001). APOA1 remained unchanged in the treated groups. Liver total and esterified cholesterol contents were twofold lower in both treated groups versus CG. CPH8 increased triacylglycerols and phospholipids (p < 0.0001) contents, while CPH17 decreased those of unesterified cholesterol (p < 0.0016). Compared with CG, CPH8 and CPH17 reduced serum (p < 0.0001) and lipoprotein hydroperoxides by stimulating paraoxonase activity (p < 0.0001). However, only CPH17 treatment reduced serum, VLDL- and HDL-malondialdehyde contents and improved glutathione peroxidase activity (p < 0.061).

Thus, chickpea protein hydrolysates and especially hydrolysed at DH = 17 per cent may have a great potential for use as a nutraceutical to reduce hypercholesterolaemia and, by consequence, oxidative stress. Therefore, the degree of enzymatic hydrolysis has a significant influence on the production of potent bioactive peptides.

The aim of this study is to examine the bioactive properties of lactobacilli‐fermented B‐vitamin soymilk, namely the in‐vitro antihypertensive property and bioconversion of isoflavone glucosides to aglycones.

Lactobacillus acidophilus BT 1088, L. fermentum BT 8219, L. acidophilus FTDC 8633 and L. gasseri FTDC 8131 were investigated for their bioactive potential and enhanced bioconversion of isoflavones in soymilk supplemented with individual B‐vitamins at a concentration of 1 mg/L.

The supplementation of thiamine, riboflavin, niacinamide, calcium pantothenate, biotin and folic acid enhanced the ACE‐inhibitory activity of lactobacilli in soymilk accompanied by a lower IC₅₀ value compared to the control (P<0.05). The β‐glucosidase specific activity of lactobacilli was also enhanced on supplementation of B‐vitamins, leading to increased bioconversion of isoflavones in soymilk. The concentration of genistein was decreased, accompanied by an increased concentration of genistein on fermentation in the presence of thiamine, niacinamide, biotin, calcium pantothenate and folic acid. Additionally, the supplementation of niacinamide, calcium pantothenate, biotin and folic acid also led to lower concentrations of malonyl daidzin, indicating increased hydrolysis of malonyl daidzin to daidzin. Results from the present study indicated that the supplementation of B‐vitamins could enhance the bioactive potential and bioconversion of isoflavones in lactobacilli‐fermented soymilk.

This work has shown that the supplementation of B‐vitamins in lactobacilli fermented soymilk has exerted in vitro ACE‐inhibitory activity and increased the accumulation of bioactive isoflavone aglycones. To the authors' knowledge, this is the first evaluation reporting on such aspects.

This study aims to study the distribution characteristics of antibiotic resistance in direct-eating food and analysis of Citrobacter freundii genome and pathogenicity. Residual antibiotics and antibiotic resistance genes (ARGs) in the environment severely threaten human health and the ecological environment. The diseases caused by foodborne pathogenic bacteria are increasing daily, and the enhancement of antibiotic resistance of pathogenic bacteria poses many difficulties in the treatment of disease.

In this study, six fresh fruits and vegetable samples were selected for isolation and identification of culturable bacteria and analysis of antibiotic resistance. The whole genome of Citrobacter freundii isolated from cucumber was sequenced and analyzed by Oxford Nanopore sequencing.

The results show that 270 strains of bacteria were identified in 6 samples. From 12 samples of direct food, 2 kinds of probiotics and 10 kinds of opportunistic pathogens were screened. The proportion of Citrobacter freundii screened from cucumber was significantly higher than that from other samples, and it showed resistance to a variety of antibiotics. Whole genome sequencing showed that Citrobacter freundii was composed of a circular chromosome containing signal peptides, transmembrane proteins and transporters that could induce antibiotic efflux, indicating that Citrobacter freundii had strong adaptability to the environment. The detection of genes encoding carbohydrate active enzymes is more beneficial to the growth and reproduction of Citrobacter freundii in crops. A total of 29 kinds of ARGs were detected in Citrobacter freundii, mainly conferring resistance to fluoroquinolones, aminoglycosides, carbapenem, cephalosporins and macrolides. The main mechanisms are the change in antibiotic targets and efflux pumps, the change in cell permeability and the inactivation of antibiotics and the detection of virulence factors and ARGs, further indicating the serious risk to human health.

The detection of genomic islands and prophages increases the risk of horizontal transfer of virulence factors and ARGs, which spreads the drug resistance of bacteria and pathogenic bacteria more widely.