Immobilized Alcalase on Micron- and Submicron-Sized Alginate Beads as a Potential Biocatalyst for Hydrolysis of Food Proteins

Abstract

Enzymatic hydrolysis of food proteins is convenient method to improve their functional properties and physiological activity. Herein, the successful covalent attachment of alcalase on alginate micron and submicron beads using the carbodiimide based chemistry reaction and the subsequent application of the beads for egg white and soy proteins hydrolysis were studied. In addition to the electrostatic extrusion technique (EE) previously used by others, the potential utilization of a novel ultrasonic spray atomization technique without drying (UA) and with drying (UAD) for alginate submicron beads production has been attempted. The immobilization parameters were optimized on microbeads obtained by EE technique (803 ± 23 µm) with respect to enzyme loading and alcalase activity. UA and UAD techniques resulted in much smaller particles (607 ± 103 nm and 394 ± 51 nm in diameter, respectively), enabling even higher enzyme loading of 671.6 ± 4 mg g−1 on the carrier and the highest immobilized alcalase activity of 2716.1 IU g−1 in the standard reaction. The UAD biocatalyst exhibited also better performances in the real food system based on egg white or soy proteins. It has been shown that the immobilized alcalase can be reused in seven successive soy protein hydrolysis cycles with a little decrease in the activity.

Keywords

• alcalase
• protein hydrolysis
• alginate submicron beads
• covalent immobilization
• electrostatic extrusion
• ultrasonic spray atomization technique