Influence of sonication pretreatment on antiradical and anti-ACE activity of protein hydrolysates from fermented pork loins.

The aim of this study was to assess whether ultrasound treatment (sonification time: 5, 15, and 30 min; constants: ∼40 kHz, ∼2.5 W cm2) can be applied prior to hydrolysis to enhance the anti-radical and angiotensin converting enzyme inhibiting (anti-ACE) effect of the hydrolysates from fermented pork loins. Enzymatic hydrolysis was performed using pepsin, followed by pancreatin. The influence of meat matrix on the course of hydrolysis, shaped using a lactic acid bacteria (LAB)-based starter culture, was also analyzed. It was found that proteases caused a systematic increase in the content of peptides, while pancreatin limited the peptide content in the protein hydrolysate from the loins subjected to spontaneous fermentation. Moreover, for these tests, sonication time had a negligible effect on the peptides content of the hydrolysates. On the other hand, for the sample of LAB-fermented products, both sonication time and stage of hydrolysis promoted the biological activity of the hydrolysates. Samples from the LAB-fermented meat had more peptides at the stage of digestion with pepsin and pancreatin, exhibiting much faster antiradical and anti-ACE activity compared to the control sample. The obtained results suggest that the use of LAB promotes the release of antiradical peptides during the two-step enzymatic hydrolysis, the duration of which can be shortened to achieve satisfactory biofunctionalities. Additional application of sonication pretreatment allows controlling the course of the hydrolysis, as the pro-health, biological effect of some protein-derived sequences is associated with the content of peptides.

Stimulation of soy seeds using environmentally friendly magnetic and electric fields.

The study analyses the impact of alternating (magnetic induction B = 30 mT for t = 60 s) and constant magnetic fields (B = 130 mT for t = 17 h) and alternating electric fields (electric current E = 5 kV/cm for t = 60 s) on various growth parameters of soy plants: the germination energy and capacity, plants emergence, the fresh mass of seedlings, protein content (Kjeldahl's method), and photosynthetic parameters (with MINI-PAM 2000 WALTZ Photosynthesis Yield Analyser and a SPAD-502 Chlorophyll Meter). Four cultivars were used: MAVKA, MERLIN, VIOLETTA, and ANUSZKA. Moreover, the advanced Machine Learning processing pipeline was proposed to distinguish the impact of physical factors on photosynthetic parameters. The use of electromagnetic fields had a positive impact on the germination rate in MERLIN seeds. The best results in terms of germination improvement were observed for alternating magnetic field stimulation in all cultivars (p > 0.05). For the VIOLETTA cultivar an increase (p > 0.05) in the emergence and overall number of plants as well as fresh mass was observed after electromagnetic field stimulation. For the MAVKA and MERLIN cultivars, the concentration of proteins in the leaves was noticeably higher in plants grown from seeds stimulated using a constant magnetic field.

Nutrition Value of Baked Meat Products Fortified with Lyophilized Dragon Fruit (Hylocereus undatus).

This study evaluates the nutritional value of a baked pork meat product containing lyophilized dragon fruit pulp. The selected nutritional properties of a baked pork meat product fortified with lyophilized Hylocereus undatus pulp in doses of 0.5%, 1.5%, 2.5%, and 4% were evaluated. For this assessment, changes in the basic chemical composition of the products, the content of calcium, magnesium, potassium, iron, and phosphorus, and the profile of fatty acids were considered. Additionally, characteristics typical for meat products, such as pH, water activity, oxidation-reduction potential or thiobarbituric acid reactive substances, and antioxidant properties of the product during 21 days of refrigerated storage, were assessed. The findings indicate that the use of higher doses of lyophilizate, i.e., in the amounts of 2.5% and 4%, significantly (p < 0.05) increases the nutritional value of meat products, leading to an increase in the concentration of essential minerals important for the proper functioning of the human body (calcium, magnesium, potassium, and iron). These changes occurred without affecting the basic chemical composition (except for an increase in the content of fat and carbohydrates in the sample with the addition of 4% lyophilizate). The introduction of the fortification treatment improved the fatty acid profile, resulting in an increase in the content of C14:0, C16:0, C20:0, and C20:5n3. In addition, in the variant with a 4% dosage, there was an increased content of C8:0, C10:0, C16:1n7, C18:0, C18:1n9C + C18:1n9t, and C18:2n6C + C18:2n6t, C18:3n3 (alpha), C20:1n15, and C20:1n9. In this particular variant, an increase in saturated-, monounsaturated-, and polyunsaturated fatty acids was also observed, which was associated with an increased level of TBARS in meat products. However, the increase in the dose of lyophilizate caused an increase in the antiradical effect of meat extracts. Based on the results obtained, it seems reasonable to use a plant additive in the form of lyophilized dragon fruit pulp in the amount of 4.0% in the production of pork meat products.

Novel α-Glucosidase Inhibitory Peptides Identified In Silico from Dry-Cured Pork Loins with Probiotics through Peptidomic and Molecular Docking Analysis.

Diabetes mellitus is a serious metabolic disorder characterized by abnormal blood glucose levels in the body. The development of therapeutic strategies for restoring and maintaining blood glucose homeostasis is still in progress. Synthetic alpha-amylase and alpha-glucosidase inhibitors can improve blood glucose control in diabetic patients by effectively reducing the risk of postprandial hyperglycemia. Peptides of natural origin are promising compounds that can serve as alpha-glucosidase inhibitors in the treatment of type 2 diabetes. Potential alpha-glucosidase-inhibiting peptides obtained from aqueous and saline extracts from dry-cured pork loins inoculated with probiotic LAB were evaluated using in vitro and in silico methods. To identify the peptide sequences, liquid chromatography-mass spectrometry was used. For this purpose, in silico calculation methods were used, and the occurrence of bioactive fragments in the protein followed the ADMET approach. The most promising sequences were molecularly docked to test their interaction with the human alpha-glycosidase molecule (PDB ID: 5NN8). The docking studies proved that oligopeptides VATPPPPPPPK, DIPPPPM, TPPPPPPG, and TPPPPPPPK obtained by hydrolysis of proteins from ripening dry-cured pork loins showed the potential to bind to the human alpha-glucosidase molecule and may act effectively as a potential antidiabetic agent.

Dipeptidyl Peptidase IV Inhibitory Peptides Generated in Dry-Cured Pork Loin during Aging and Gastrointestinal Digestion.

The ability of peptides from an aqueous and salt-soluble protein extract of dry-cured pork loins to inhibit the action of dipeptidyl peptidase IV was determined. This activity was assessed at different times of the production process, i.e., 28, 90, 180, 270 and 360 days. The resistance of the biological property during the simulated digestive process was also assessed. For this, the extracts were hydrolyzed with pepsin and pancreatin as a simulated digestion step of the gastrointestinal tract and fractionated (>7 kDa) as an intestinal absorption step. The results indicate that dried-pork-loin peptides may have potential as functional food ingredients in the prevention and treatment of type 2 diabetes mellitus. In particular, the APPPPAEV, APPPPAEVH, KLPPLPL, RLPLLP, VATPPPPPPK, VPIPVPLPM and VPLPVPVPI sequences show promise as natural food compounds helpful in maintaining good health.

Potential DPP IV Inhibitory Peptides from Dry-Cured Pork Loins after Hydrolysis: An In Vitro and In Silico Study.

Peptidyl peptidase IV (DPP-IV) is a pharmacotherapeutic target in type 2 diabetes, and inhibitors of this enzyme are an important class of drugs for the treatment of type 2 diabetes. In the present study, peptides (<7 kDa) isolated from dry-cured pork loins after pepsin and pancreatin hydrolysis were identified by mass spectrometry and tested as potential inhibitors of DPP-IV by the in silico method. Two peptides, namely WTIAVPGPPHS from myomesin (water-soluble fraction, A = 0.9091) and FKRPPL from troponin (salt-soluble fraction, A = 0.8333), were selected as the most promising inhibitors of DPP-IV. Both peptides were subjected to ADMET analysis. Fragments of these peptides showed promising drug-likeness properties as well as favorable absorption, distribution, metabolism, excretion, and toxicity functions, suggesting that they are novel leads in the development of DPP-IV inhibitors from food.

Structure-activity relationships study on biological activity of peptides as dipeptidyl peptidase IV inhibitors by chemometric modeling.

The aim of this study is to identify the potential descriptors affecting the inhibitory activity of the peptides inhibiting dipeptidyl peptidase IV (DPP-IV). This study provides important information for assessing the biological activity of the new peptide sequences of food origin or making structural modifications to the current inhibitors to improve their performance. For this purpose, the chemometric method describing the relationship between the structure of food peptides and their biological activity (structure-activity relationship [SAR]) was used to theoretically predict the potential of bioactivity of peptides. Data on the physicochemical properties of amino acids in the dipeptides acting as inhibitors of DPP-IV were collected and analyzed for using these properties as descriptors in further analysis. A total of 252 dipeptide sequences with confirmed DPP-IV inhibitory activity available in the BIOPEP-UWM database were included in the analysis, and 16 descriptors defining individual amino acids (such as molecular weight, polarity, hydropathicity, bulkiness, buried residue, and acceptable and normalized frequency of alpha-helix and beta-sheet) were identified. Based on this information, a data matrix was constructed and used in the chemometric analysis (principal component analysis and multiple linear regression). From the SAR model created, a multiple regression equation was derived to predict the biological activity of the dipeptide DPP-IV inhibitors.

Effect of Marination Time on the Antioxidant Properties of Peptides Extracted from Organic Dry-Fermented Beef.

In this study, we evaluated the effect of marination time on changes in the antioxidant properties of peptides extracted from bovine semimembranosus muscle. We measured antiradical scavenging capacity and reducing power of the peptides using a spectrophotometric decolorization method; inhibition of lipid oxidation was also assessed by estimating the level of malondialdehyde formed. According to our results, there was no benefit from the doubling of marinating time (from 24 to 48 h) as part of the preprocessing of beef. Samples from S1 batch (24 h marination) showed better antioxidant properties than those from S2 batch. We also tested various color parameters as a reflection of the inhibition of oxidative processes, in which case, the most favorable parameters from the consumer point of view were found to be lightness and redness. The effect of marination time on the degree of proteolytic changes was estimated using peptidomic approach. The degradation of myoglobin, hemoglobin, creatine kinase-type M, and beta-enolase-as the most sensitive proteins to proteolytic degradation-was observed during the 62 days of processing. It seems that the prolongation of marination time as a preprocessing step intensifies the hydrolytic degradation of proteins and peptides during the processing step. This results in the loss (or it has no effect) of antioxidative properties in organic dry-fermented beef.

Meat Proteins as Dipeptidyl Peptidase IV Inhibitors and Glucose Uptake Stimulating Peptides for the Management of a Type 2 Diabetes Mellitus In Silico Study.

Diabetes mellitus is a non-communicable disease entity currently constituting one of the most significant health problems. The development of effective therapeutic strategies for the prevention and/or treatment of diabetes mellitus based on the selection of methods to restore and maintain blood glucose homeostasis is still in progress. Among the different courses of action, inhibition of dipeptidyl peptidase IV (DPP-IV) can improve blood glucose control in diabetic patients. Pharmacological therapy offering synthetic drugs is commonly used. In addition to medication, dietary intervention may be effective in combating metabolic disturbances caused by diabetes mellitus. Food proteins as a source of biologically active sequences are a potential source of anti-diabetic peptides (DPP-IV inhibitors and glucose uptake stimulating peptides). This study showed that in silico pork meat proteins digested with gastrointestinal enzymes are a potential source of bioactive peptides with a high potential to control blood glucose levels in patients with type 2 diabetes mellitus. Analysis revealed that the sequences released during in silico digestion were small dipeptides (with an average weight of 270.07 g mol-1), and most were poorly soluble in water. The selected electron properties of the peptides with the highest bioactivity index (i.e., GF, MW, MF, PF, PW) were described using the DFT method. The contribution of hydrophobic amino acids, in particular Phe and Trp, in forming the anti-diabetic properties of peptides released from pork meat was emphasized.

Technological and nutritional properties of meat from female wild boars (Sus scrofa scrofa L.) of different carcass weights.

The aim of this work was to assess the technological and nutritional quality of meat from female wild boars. The muscle samples - Musculus longissimus thoracis et lumborum (LTL) and Musculus semimembranosus (SM) - were taken from a total of 40 female wild boar after a hunt. Carcasses were allocated to five groups according to weight (group I - 30 ± 5  kg; group II - 45 ± 4.9  kg; group III - 60 ± 4.7  kg; group IV - 75 ± 5.2  kg; group V - 90 ± 5  kg). Studies that have been carried out have shown that technological and nutritional properties of meat from wild boars depend on the mass of carcasses and the type of muscle. The pH of analyzed wild boar meat proved that there was normal glycolysis and glycogenolysis progress in all groups. The water holding capacity (WHC) of SM muscles from the lowest-weight carcasses was significantly ( P ≤ 0.01 ) lower as compared to the heavier carcasses. There were significant differences ( P ≤ 0.01 ) in the shear force of the LTL muscle between groups I, IV and V. The muscles cut from carcasses of a higher mass represent higher values of this parameter. The higher-mass carcasses were characterized by a darker color, which resulted from the higher concentration of myoglobin. The protein concentration increased with carcass weight. A similar effect of carcass weight on the content of intramuscular fat (IMF) was found. Due to the low calorie content, the meat of young wild boar may be an interesting and attractive component of the diet.

Stability of Antiradical Activity of Protein Extracts and Hydrolysates from Dry-Cured Pork Loins with Probiotic Strains of LAB.

The application of starter cultures to improve quality and safety has become a very common practice in the meat industry. Probiotic strains of lactic acid bacteria (LAB) can also bring health benefits by releasing bioactive peptides. The aim of this work was to evaluate the stability of antiradical activity of protein extracts from LAB-inoculated dry-cured pork loins during long-term aging and evaluate their hydrolysates after simulated gastrointestinal digestion. Analyses of hydrolysates by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) were strengthened with in silico analysis. The highest antiradical activity of the protein extracts was observed after 180 days of aging. The influence of the strain used (LOCK, BAUER, or BB12) on the inactivation ability of ABTS radicals varied during long-term aging. The IC50 values indicated the higher antiradical properties of salt-soluble (SSF) compared to water-soluble fraction (WSF) of proteins. The peptides generated by in vitro digestion have MW between 700 and 4232 Da and their length ranged from 5 to 47 amino acids in a sequence where Leu, Pro, Lys, Glu, and His had the largest share. This study demonstrates that the degradation of pork muscle proteins during gastrointestinal digestion may give rise to a wide variety of peptides with antiradical properties.

Potential of bacteriocins from lab to improve microbial quality of dry-cured and fermented meat products.

Meat and meat products are an important component of the daily diet. Nevertheless, they are perishable goods and are prone to microbial contamination, which leads to an increased risk to the health of consumers as well as economic losses in the meat industry. Fermentation has been used for thousands of years to preserve meat. As a result of extensive biochemical reactions occurring in meat during fermentation and ripening, the condi- tions inhibiting the growth of pathogenic and spoilage bacteria are formed. These changes are catalyzed by endogenous meat enzymes and exogenous enzymes derived from natural contaminating bacteria or starter cultures applied. In dry-cured and fermented meat products they are represented mainly by lactic acid bacte- ria (LAB) that produce a wide range of compounds, such as bacteriocins, directed against other microorgan- isms. The use of bactericidal peptides does not affect the sensory quality of foodstuffs, so that they attract attention as alternative means of preserving the stability and safety of dry-cured products.

Antimicrobial Peptides of Meat Origin - An In silico and In vitro Analysis.

The aim of this study was to evaluate the antimicrobial activity of meat protein-derived peptides against selected Gram-positive and Gram-negative bacteria. The in silico and in vitro approach was combined to determine the potency of antimicrobial peptides derived from pig (Sus scrofa) and cow (Bos taurus) proteins. The in silico studies consisted of an analysis of the amino acid composition of peptides obtained from the CAMPR database, their molecular weight and other physicochemical properties (isoelectric point, molar extinction coefficient, instability index, aliphatic index, hydropathy index and net charge). The degree of similarity was estimated between the antimicrobial peptide sequences derived from the slaughtered animals and the main meat proteins. Antimicrobial activity of peptides isolated from dry-cured meat products was analysed (in vitro) against two strains of pathogenic bacteria using the disc diffusion method. There was no evidence of growthinhibitory properties of peptides isolated from dry-cured meat products against Escherichia coli K12 ATCC 10798 and Staphylococcus aureus ATCC 25923.

Effect of Lactobacillus acidophilus Bauer and Bifidobacterium animalis ssp. lactis BB12 on proteolytic changes in dry-cured loins.

The effect of the potentially probiotic bacteria strain of Lactobacillus acidophilus Bauer and probiotic bacteria Bifidobacterium animalis ssp. lactis BB12 on proteolytic changes of proteins in dry-cured loins during fermentation and cold storage was studied. Results of the conducted tests demonstrated that the use of probiotic bacteria for the production of dry-cured meats impacts the generation of products of protein proteolysis with high antioxidant activity. The highest antioxidant activity of peptides after fermentation and cold storage was observed in the loin with the strain B. animalis ssp. lactis BB12 and the loin with the mixture of strains L. acidophilus Bauer and B. animalis ssp. lactis BB12. Qualitative analysis of peptides demonstrated that peptides with weight below 3.5 kDa are characterized by the highest capacity of quenching the ABTS cation radical, including the peptides in loins with the strain B. animalis ssp. lactis BB12.

Porcine myofibrillar proteins as potential precursors of bioactive peptides - an in silico study.

Selected porcine myofibrillar proteins have been assessed as potential precursors of bioactive peptides based on in silico analysis. The potential of protein sequences for releasing peptides was evaluated by determining the profile of their potential biological activity and the frequency of occurrence of fragments with a given activity using the BIOPEP database. Digestive enzymes: pepsin, trypsin and chymotrypsin have been used for the in silico proteolysis with the use of the "Enzyme(s) action" tool in BIOPEP. After simulated gastrointestinal digestion the tested sequences of pig myofibrillar proteins are a potential source of a total of 399 peptides with activities such as enzyme inhibition, antioxidative, hypotensive, stimulating or regulating various body functions and antiamnestic activities. Within the intact proteins and after simulated gastrointestinal digestion, dipeptidyl peptidase IV inhibitory peptide sequences were the most frequently observed. The results indicate that pork myofibrillar proteins are a promising source of peptides with biological activity.

Meat and fermented meat products as a source of bioactive peptides.

Bioactive peptides are short amino acid sequences, that upon release from the parent protein may play different physiological roles, including antioxidant, antihypertensive, antimicrobial, and other bioactivities. They have been identified from a range of foods, including those of animal origin, e.g., milk and muscle sources (with pork, beef, or chicken and various species of fish and marine organism). Bioactive peptides are encrypted within the sequence of the parent protein molecule and latent until released and activated by enzymatic proteolysis, e.g. during gastrointestinal digestion or food processing. Bioactive peptides derived from food sources have the potential for incorporation into functional foods and nutraceuticals. The aim of this paper is to present an overview of the muscle-derived bioactive peptides, especially those of fermented meats and the potential benefits of these bioactive compounds to human health.

Changes in selected parameters related to proteolysis during ageing of dry-cured pork loins inoculated with probiotics.

The effect of inoculation with a probiotic strain, Lactobacillus casei LOCK 0900, on selected parameters related to proteolysis of dry-cured pork loins during ageing was studied. Moisture content decreased significantly (p<0.05) throughout ageing, accompanied by a progressive reduction in water activity. The total nitrogen (TN) content increased during ageing with no effect (p<0.05) of inoculation with L. casei on its level. The greatest increase in non-protein nitrogen (NPN) content during ageing occurred in an inoculated sample, corresponding with the more pronounced decrease in pH. The intensity of proteolysis, as assessed by proteolysis index (PI), remained statistically significantly (p<0.05) unchanged during examined ageing periods. Inoculation with a probiotic strain does not significantly affect the degree of proteolysis in examined meat products after 21 and 28 days of ageing.

Biogenic amines content during extended ageing of dry-cured pork loins inoculated with probiotics.

The study determined the content of biogenic amines in dry-cured pork loins inoculated with Lactobacillus casei LOCK 0900 probiotic strain, in 4, 8 and 16 month-old samples. Cadaverine, putrescine and tryptamine levels showed a time-dependent increase during ageing. Histamine and spermidine were not detected. Spermine which was present at very low concentrations, tended to decrease. Cadaverine and tryptamine were the main biogenic amines at the end of the ageing period with average values of 39.6 mg/kg and 49.2 mg/kg respectively. The results were within the values reported for other dry-cured meat products and below the suggested toxic levels. The pH of samples increased significantly (p<0.05) with ageing time. The a(w) values decreased significantly (p<0.05) during ageing, with a mean value of 0.953±0.007 for samples aged for 4 months, and 0.852±0.007 for samples aged for 16-months.