Acidified milk products like yoghurt are an important food product but
there are relatively few reports on the mechanisms involved in gel fo
rmation and the effects of processing variables such as heat treatment
and gelation temperature on the important physical properties (such a
s whey separation) of acid-induced gels. Most previous reviews have de
scribed the microbiology of the starter cultures and technologies used
in yoghurt manufacture. Recent developments are reviewed including th
e use of techniques such as dynamic low amplitude oscillatory rheology
to monitor the gel formation process; confocal scanning laser microsc
opy to examine gel microstructure; and various models for the aggregat
ion of particle gels are discussed in terms of possible mechanisms inv
olved in the formation of acid-induced milk gels. (C) 1998 Canadian In
stitute of Food Science and Technology. Published by Elsevier Science
Ltd. All rights reserved.