Intermicellar relationships in rennet-treated separated milk: II. Process of gel assembly

Abstract

Summary The aggregation of casein micelles in milk by the action of rennet, examined by electron microscopy and viscometry, was correlated with visually-observed coagulation. The spatial relationships between micelles were quantified from measurements made on micrographs. Aggregation did not start until about 60% of the rennet-clotting time, when the enzymic action was almost complete. The micelles tended to form chains which then linked into a loose network. This became more extensive with time as the average size of the aggregates increased. By the clotting time, most micelles were in contact with another and a network was beginning to form. Initially, micelles probably linked by bridges. These then appeared to contract, bringing the particles into contact and eventually causing partial fusion.