ALPHA-AMYLASE INHIBITORY PROPERTIES AND ANTIOXIDANT POTENTIALS OF ALBIZIA LEBBECK SEED PROTEIN HYDROLYSATES

ABSTRACT The growing global prevalence of diabetes mellitus and its associated oxidative stress has intensified the demand for natural therapeutic agents with dual enzyme-inhibitory and antioxidant properties. This study evaluated the α-amylase inhibitory activity and antioxidant potential of Albizia lebbeck seed protein hydrolysates. Protein isolates were enzymatically hydrolyzed using trypsin and chymotrypsin, and their peptide yield, degree of hydrolysis (DH), α-amylase inhibition, DPPH radical scavenging, and ferric reducing antioxidant power (FRAP) were assessed. The peptide yields were 93.09±0.92% and 78.99±1.42%, with DH values of 68.85±0.92% and 71.24±1.47% for chymotryptic and tryptic hydrolysates respectively. Both hydrolysates displayed\] dose-dependent inhibition of α-amylase, with tryptic hydrolysates exhibiting stronger inhibition. Antioxidant activity showed that tryptic digests had superior DPPH scavenging at lower concentrations, while chymotryptic digests excelled at higher concentrations. FRAP analysis revealed that tryptic hydrolysates possessed stronger ferric reducing ability than chymotryptic ones, though both were significantly lower than ascorbic acid. These findings suggest that Albizia lebbeck seed proteins are viable sources of bioactive peptides with anti-diabetic and antioxidant potential. The study highlights the therapeutic relevance of enzymatically derived peptides in developing functional foods or nutraceuticals targeting diabetes and oxidative stress. Keywords: Albizia lebbeck, α-Amylase inhibition, Protein hydrolysates, Antioxidant activity.