Evidence for an antihypertensive effect of a land snail (Helix aspersa) by-product hydrolysate – Identification of involved peptides

A comprehensive review of bioactive peptides obtained from animal byproducts and their applications

Livestock generates high quantities of residues, which has become a major socioeconomic issue for the meat industry. This review focuses on the identification of bioactive peptides (BPs) in animal byproducts and meat wastes. Firstly, the main bioactivities that peptides can have will be described and the methods for their evaluation will be discussed. Secondly, the various origins of these BPs will be studied. Then, the techniques and tools for the generation of BPs will be detailed in order to discuss, in the final part, how peptides could be used and assimilated. BPs possess diverse biological activities and can be strategic candidates for substituting synthetic molecules. In silico potentiality studies are a helpful tool to understand and predict BPs released from proteins and their potential activities. However, in vitro validation is often required. Although BP use is compelled by strict regulations in relation to the field of application, they are also limited by their low bioavailability and bioaccessibility. Therefore, it is important to test peptide stability during gastrointestinal digestion. Protective strategies have been discussed since their use could improve the stability and effectiveness of BPs.

Workflow towards the generation of bioactive hydrolysates from porcine products by combining in silico and in vitro approaches

Food-derived bioactive peptides have generated an increasing interest in the field of health and well-being research. They can act either against the metabolic syndrome, participate in regulating the oxidation balance or act on the immune system. The aim of this study is to develop a workflow to generate bioactive peptides from three porcine offals namely, heart, liver, and lung and one muscle the Longissimus Dorsi, by combining in silico and in vitro approaches. Bioinformatics tools (e.i. BIOPEP and Uniprot) permitted to orientate the choice of enzymes for generating abundant bioactive peptides from the four studied porcine products. With papain and subtilisin, the main bioactivities potentially released were ACE inhibitors, DPP4 inhibitors and antioxidant peptides. An in vitro validation study using papain and subtilisin demonstrated high DPP4 inhibitors and antioxidant bioactivities for the generation of peptides. This work allowed: i) the identification of all proteins that composed porcine heart, liver, lung and LD muscle that could be useful for the scientific community, ii) the development of a workflow to select most abundant proteins in a product while considering abundance factors and iii) the potential of porcine meat and offals to generate DPP4 inhibitors and antioxidant peptides. However, there is still a need in developing new tools in order to face limitations of mass spectrometry for the identification of peptides with less than six amino acids. Such a work may contribute to the development of the circular economy and the innovative creation of value-added products from animal production.

Isolation, Purification and Characterization of Antioxidative Bioactive Elastin Peptides from Poultry Skin

Muscle-based by-products are often undervalued although commonly reported having a high amount of natural bioactive peptides. In this study, elastin was isolated from the protein of broiler hen skin while its hydrolysate was prepared using Elastase. Assessment of antioxidative properties of elastin-based hydrolysate (EBH) was based on three different assays; 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical and metal chelating ability. The EBH was purified further using ultrafiltration, gel filtration and Reverse- Phase High-Performance Liquid Chromatography (RP-HPLC). The IC50 of ABTS radical activities for EBH were decreased as EBH further purified using ultrafiltration (EBH III; 0.66 mg/mL)>gel filtration (EB-II; 0.42 mg/mL)>RP-HPLC (EB-II4; 0.12 mg/mL). The sequential identification of the peptide was done by matrix-assisted laser desorption/ ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/ TOF-MS) of the potent fractions obtained from RP-HPLC (EB-II4). The presence of hydrophobic amino acids (Val and Pro) in the peptide sequences could potentially contribute to the high antioxidant activity of EBH. The sequences GAHTGPRKPFKPR, GMPGFDVR and ADASVLPK were identified as antioxidant peptides. In conclusion, the antioxidative potential from poultry skin specifically from elastin is evident and can be explored to be used in many applications such as health and pharmaceutical purposes.