Meat Waste Valorization through Protein Hydrolysis using Different Types of Proteases

Abstract

Five different commercial proteases (Alcalase 2.4L, Flavourzyme 1000L, Neutrase, Protamex, and PTN) were evaluated for the simultaneous recovery of protein and lipids through hydrolysis. The hydrolysis reaction was monitored using the pH-stat procedure, in which samples were collected after 240 min of hydrolysis using each enzyme. The samples were analyzed for the degree of hydrolysis, protein hydrolysate, collagen, lipids, and fatty acids. A clear relationship was observed between the degree of hydrolysis and the amounts of recovered products. Serine endopeptidases from the microbial source (Alcalase) resulted in the maximum degree of hydrolysis (27.5%), lipid recovery (82.6%), and protein hydrolysates quality (average molecular weight of the hydrolysates = 472 Dalton), followed by formulations of serine protease and metalloprotease from the microbial source (Protamex). Metalloproteases from the microbial source (Neutrase) resulted in maximum collagen recovery (87.1%). Serine endopeptidases from the animal source (PTN) and endo/exopeptidases from the fungal source (Flavourzyme) exhibited an intermediate efficacy between Alcalase and Neutrase. In the case of all proteases, the product fatty acid profile matched well with that of the meat waste, which suggests that no chemical changes occurred in the lipids after the hydrolysis with the evaluated proteases. These results suggest that hydrolysis using proteases could serve as an ecofriendly and viable alternative for obtaining additional value from meat waste.