Different coagulation behaviour of bacteriologically acidified and renneted milk: the importance of fine-tuning acid production and rennet action

The phenomenon of milk gel formation by combined continuous acidification a nd renneting was examined using small deformation dynamic rheometry. A clea r gradation in coagulation behaviour was demonstrated based on systematic r heo-kinetic analyses of gel development from milks that were cultured and r enneted to varying degrees. Three basic (homologous) patterns of coagulatio n were distinguished, which were related to different degrees of renneting and distinct mechanisms of coagulation. The different behaviours identified have a direct bearing on cheese technology but they were not clearly recog nised in the past. Their relatedness was not established either. A unifying conceptual scheme is put forward., which emphasises the importance of fine -tuning acid production and rennet action in relation to gelation mechanism s and gel viscoelastic properties. The proposed framework facilitates an un derstanding of experimental observations. The premise is that different pat terns of gel development stem (mainly) from different patterns of successio n of continuous acidification vs. renneting. (C) 2001 Elsevier Science Ltd. All rights reserved.