Complex sentence: One of the oldest applications of homogenization is in milk processing, the mixing of several different milking herds and/or dairies to produce a more consistent raw milk prior to processing and to prevent or delay natural separation of cream from the rest of the emulsion.
Split into simpler sentences: One of the oldest applications of homogenization is in milk processing, the mixing of several different milking herds and/or dairies to produce a more consistent raw milk prior to processing. Then to prevent or delay natural separation of cream from the rest of the emulsion.