Preparation, characterization, antioxidant activity evaluation, and potential application of Peruvian squid liver...

This study employed three distinct methods to prepare Peruvian squid liver protein hydrolysates (PSLPHs), characterized their structure, and evaluated their antioxidant activities. Furthermore, these hydrolysates were utilized as fertilizers to investigate their effects on the growth of tomato seedlings. The results indicated that PSLPHs prepared using the biological enzymatic hydrolysis combined with ultrasound-assisted autolysis (B&U) treatment demonstrated the highest content of aromatic amino acids (Tyr + Phe: 5.499 g/100 g). Additionally, the molecular weight was found to be 99.21 % below 3 kDa, exhibiting a total antioxidant activity of 52.73 %, with solubility exceeding 80 % at pH 5.5-6.5. Furthermore, when diluted 100-fold and applied as fertilizer for tomato seedlings, the PSLPHs promoted root system growth, and enhanced stem and blade growth. This research innovatively employed the B&U method to prepare PSLPHs and assessed their effects on the growth of tomato seedlings, providing a theoretical basis for the application of protein hydrolysate-based water-soluble fertilizers.