Synergistic effects of various lipases and phospholipase C on milk fat

The enzyme, phospholipase C, from a number of psychrotrophs isolated from milk was shown to survive HTST pasteurization and UHT sterilization processes. The phospholipase C of Bacillus cereus was able to increase lipolytic activity of a commercial lipase preparation and native milk lipoprotein lipase in raw milk by making the substrate more susceptible to hydrolysis: phospholipase C had no effect on the lipase activity of a fluorescent Pseudornonas spp. The enhancement of lipolysis by phospholipase C was affected by pronase and papain, but not by trypsin. Homogenization of the raw milk had the same effect on lipolysis by lipoprotein lipase as addition of phospholipase C.