Enzymatic hydrolysis of protein-rich vegetable matrices. Production and bioactivity evaluation of Hydrolyzed Vegetable Proteins

Protein-rich food are a source of bioactive hydrolysates and peptides that have a potential as health-promoting functional foods, dietary supplements and pharmaceutical products. Bioactive peptides are short sequences of amino acids that are inactive within the sequence of the parent protein but can display interesting biological functions once they are released after protein hydrolysis (i.e. gastro-intestinal digestion, food processing, microbial fermentation, chemical and/or enzymatic hydrolysis). (1) To date, numerous peptides and hydrolysates with a biological function, such as angiotensin converting enzyme inhibition, mineral binding, antidiabetic, satiating, immunomodulating, opioid, antioxidant, or antimicrobial activities, have been reported. (2,3) Challenges for production of bioactive peptides include: (i) the development of efficient bioprocesses for peptide production, (ii) the identification and isolation of new molecules, (iii) the elucidation of the mechanisms of action involved in their bioactivities. The lack of economically viable, large-scale purification and characterization techniques is limiting the development of industrial production of bioactive peptides and hydrolysates. (2) Inexpensive protein sources to be used as raw materials and new production and separation technologies are, indeed, being sought. Starting from the know-how developed over the years in the valorization of protein-rich feedstock such as hemp (3), flax (4), and rice (5), the residue derived from soybean and sunflower seeds was here exploited for the production of protein hydrolysates (HVP, Hydrolyzed Vegetable Proteins). Enzymatic methods based on proteases are the most common way to produce bioactive peptides. The use of enzymes is preferred to other processes since reproducible molecular weight profiles and peptide composition are usually obtained. Moreover, enzymatic methods are safer and milder than acid hydrolysis. The critical hydrolysis parameters (temperature, pH, aqueous or buffered solution) must be optimized for each protein substrate and each selected enzyme or combination of enzymes. Enzymatic hydrolysis of soy proteins by food-grade proteases was carried out. Enrichment of peptides contained in HVP mixtures was achieved by using membrane filtration procedures (110 kDa). The resulting HVP fractions are currently under evaluation for their antimicrobial activity. Upgrading of agro-food residues by enzyme-aided processes (i.e. biocatalysis) to obtain high-added value products is a clear example of “circular economy” where waste or by-products are managed sustainably by turning them into a resource, thus contributing to the development of new production pipelines and patterns. (6) References: 1. T. Lafarga and M. Hayes, Food Rev. Int., 33 (2017) 217-246. 2. C. Raveschot, B. Cudennec, F. Coutte, C. Flahaut, M. Fremont, D. Drider and P. Dhulster, Front. Microbiol., 9 (2018) 2354. 3. L.P. Orio, G. Boschin, T. Recca, C.F. Morelli, L. Ragona, P. Francescato, A. Arnoldi and G. Speranza, J. Agric. Food Chem., 65 (2017) 10482-10488. 4. T. Kaewmanee, L. Bagnasco, M. Benjakul, S. Lanteri, C. Morelli, G. Speranza and M.E. Cosulich, Food Chem., 148 (2014) 60-69. 5. L. Bagnasco, V.M. Pappalardo, A. Meregaglia, T. Kaewmanee, D. Ubiali, G. Speranza and M.E. Cosulich, Food Res. Int., 50 (2013) 420-4272. 6. A. Pellis, S. Cantone, C. Ebert and L. Gardossi, New Biotechnol., 40 (2018) 154-169. This project (2017-0978) was funded by Cariplo Foundation (Italy)