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.

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.

Consumption of food products with a high level of compounds that are products of fat or protein oxidation is associated with the onset of various diseases. Therefore, this study estimated the level of oxidation in a fermented long-maturing tenderloin inoculated with lactic acid bacteria strains. To estimate the level of fat and protein exposure to oxidative factors, thiobarbituric acid reactive substances (TBARS), oxidation–reduction potential (ORP), oxygenation index (Ox_i) as well as surface hydrophobicity (HS) of protein, and the content of free sulfhydryl (SH) groups were used as indicators of oxidation status. To validate the results, changes in the color of the products were determined using instrumental methods. This study confirmed the relationship between fat oxidation (based on TBARS) and oxidation of myoglobin as a protein representative (based on Oxi). Indeed, statistical analysis showed that TBARS, Oxi and SH were correlated with each other and could be used as indicators of oxidation in fermented products. The findings of this study also showed the use of LAB as starter cultures for meat fermentation may have an impact on the level of oxidation; in particular, the BAUER strain showed a protective effect on proteins in the final stages of the production of dry-cured pork loins.

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.

This study focuses on collecting actual data on the workable possibility of reducing the technological use of nitrites in beef products according to the present trends in nutrition, especially in terms of European Union (EU) food law. Measurements of safety by technological (pH value, water activity, N-nitrosamine), microbiological, oxidative stability (thiobarbituric acid reactive substances, oxidation-reduction potential), and color parameter (CIE L*a*b*, total heme pigment and heme iron) methods were taken after production and storage. The roasted beef with a reduced inclusion level of sodium nitrite (75 mg/kg and below) was more vulnerable to lipid oxidation. The quantities of primary lipid oxidation products were related to the sodium nitrite inclusion level (50–150 mg/kg). Clostridium spp., Staphylococcus aureus, and Listeria monocytogenes were not detected in any of the samples tested during all the experiments. The total count of Enterobacteriaceae increased with the decrease in sodium nitrite content, from log 2.75 cfu/g at the highest to log 6.03 cfu/g at the smallest addition of nitrite. The obtained results revealed that the addition of 100 mg/kg of sodium nitrite would be adequate for minced roasted beef, without significant unexpected effects on color, oxidative stability, and microbiological safety compared with the control (150 mg/kg).