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Dynamics of isoelectric precipitation of casein using sulfuric acid
Author(s) -
Hofland G. W.,
Berkhoff M. R.,
Witkamp G. J.,
van der Wielen L. A. M.
Publication year - 2003
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690490828
Subject(s) - precipitation , chemistry , sulfuric acid , isoelectric point , mixing (physics) , casein , chromatography , chemical engineering , particle size , inorganic chemistry , food science , biochemistry , meteorology , physics , quantum mechanics , engineering , enzyme
The acid precipitation of casein from skim milk is an interesting and complex operation, as it involves several mechanistic steps occurring simultaneously. Research has focused so far on the influence of static variables such as temperature and final pH on the curd properties. Here the dynamics of the process was investigated. From a characteristic times analysis it was concluded that the most important mechanistic steps in the acid precipitation of casein were acid mixing, aggregation/breakup, and transport in/out of the precipitate particles. Experiments in a fed batch setup using sulfuric acid as the precipitant showed how the precipitation influenced the pH profile and demonstrated the large influence of process variables, such as the acid addition rate, the mixing intensity, and aging time on particle‐size distributions and the release of minerals from the casein.