Production of a transglutaminase from Zea mays in Escherichia coli and its impact on yoghurt properties

A gene from Zea mays coding a TGase was expressed in E. coli and identified by Western blotting. Under optimal expression conditions, the production and specific activity of refolded TGZ were 1.41 mg/L and 0.34 U/mg. The activated TGZ was employed to cross-link milk proteins. The yoghurt treated with TGZ showed a lower syneresis, higher apparent viscosity and texture than untreated yoghurt. The properties of TGZ-treated sample were better than those of MTG-treated samples, so TGZ may have potential as an additive in yoghurt manufacture.