Enhancing zein functionality through sequential limited Alcalase hydrolysis and transglutaminase treatment: Structural changes and functional properties
Adieh Anvar, Mohammad Hossein Azizi, Hassan Ahmadi Gavlighi
Abstract
This study investigated the effects of sequential enzymatic hydrolysis using Alcalase, followed by transglutaminase conjugation on the secondary and tertiary structures, hydrophobicity, free amine content, protein-protein interactions, and functional properties of zein. Fourier-transform infrared spectroscopy showed that the most significant secondary structural changes, characterized by a decrease in α-helix content and an increase in β-turns, occurred at a higher degree of hydrolysis. At a 2 % degree of hydrolysis, it revealed notable emulsifying activity (65.96 m 2 /g), while at 5 % hydrolysis, it achieved the highest solubility (75.06 %). Additionally, the zein hydrolysate with a 7 % hydrolysis degree, treated with transglutaminase, demonstrated improved H 0 values (2992.33), enhanced foam capacity (65.95 %), and increased solubilized protein content in a dithiothreitol extract It can hydrolyze zein into numerous amphipathic polypeptide fragments, resulting in the generation of ant (31.35 %). Meanwhile, native zein treated with transglutaminase showed the highest water holding capacity (4.47 g/g). Overall, the combined enzymatic approach modified zein structure and properties, suggesting potential for improving functionality in plant-based food applications. • Sequential Alcalase and transglutaminase (TGase) modified zein tertiary structure. • Limited hydrolysis showed the highest emulsifying properties and solubility. • TGase treatment exhibited the highest foam properties and water holding capacity. • Zein hydrolysate a 7 % with TGase exhibited the highest foam capacity and stability.