Cross-linking casein micelles by a microbial transglutaminase conditions for formation of transglutaminase-induced gels

The conditions for obtaining transglutaminase-induced casein gels have been studied by rheological measurements. The experiments have been performed with pure micellar casein. Different parameters were investigated including enzyme concentration, protein concentration, pH, ways of acidification, gelation temperature, etc. The conditions of gel formation are clearly based on a compromise between the conditions required for casein gelation and those controlling the intra- and inter-micellar cross-linking mechanisms of casein micelles. Such conditions involve control of enzyme activity (pre-incubation, pH and temperature dependence) as well as control of the casein micelle aggregation (pH and temperature dependence).