CTAB electrophoresis and immunoblotting: a new method for the determination of soy protein in meat products

Abstract

A CTAB electrophoresis method that is able to separate soy protein on the basis of molecular mass is introduced. The cationic detergent CTAB (N-cetyl-N,N,N-trimethylammoniumbromide) is not as denaturing as sodium dodecyl sulphate (SDS), and thereby allows separation of proteins that are virtually unchanged from their naturally occurring state. After blotting on a nitrocellulose (NC) membrane, the protein can be detected by a soy-specific antibody. Soy protein isolates, concentrates and hydrolysates as well as meat products containing these soy protein products were separated by CTAB electrophoresis and blotted on NC membranes. As little as 0.5% soy protein in meat products could be detected, even if the meat product had been heated to 120°C for 30 min during the manufacturing process.