Abstract This study evaluated the valorization of meat trimming waste through the production of protein hydrolysates and assessed the influence of extraction pH on their compositional and functional properties. Proteins were extracted under acidic (pH 2.5 and 3.0) and alkaline (pH 11 and 12) conditions and subsequently hydrolyzed with alcalase. The hydrolysates were analysed for dry matter, crude protein, non-protein nitrogen substances (NPN-S), degree of hydrolysis (DH), protein yield, total sulfhydryl (SH) content, antioxidant capacity, ACE-inhibitory activity, and emulsifying properties. Extraction pH exerted very significant (p 0.01) effects on NPN-S, SH content, ACE-inhibitory activity, and emulsion activity, and significant (p 0.05) effects on dry matter, crude protein, protein yield, and emulsion stability. Alkaline extraction, particularly at pH 11, enhanced protein solubilization, yield, SH content, and emulsifying activity, suggesting increased protein unfolding and thiol exposure. Acidic extraction, notably at pH 3, resulted in higher dry matter, NPN-S, and ACE-inhibitory activity. DH did not differ among treatments, indicating consistent enzymatic efficiency, and antioxidant activities remained statistically similar. Principal component analysis distinctly separated acidic and alkaline hydrolysates, confirming the strong influence of extraction pH. Overall, meat trimming waste demonstrated strong potential as a sustainable substrate for generating multifunctional protein ingredients.
Terzioğlu et al. (Tue,) studied this question.