The character of casein micelles influences forces that control gelation,
therefore, changes on casein micelle depend on both temperature and pH value.
Hydrophobic interactions, which play the most significant role in gelation of
casein micelle, are favored at higher temperatures (Goddard and Augustin,
1995). Hydrophobic interactions are weaker while repulsive forces are enhanced
at lower temperature, so repulsive forces have to be reduced to a greater extent
during acidification before intermicellar attractions can dominate. This could
explain variations in pH value at the onset of gelation at different temperatures