Hydrolytic Rancidity in Milk. IV. Relation Between Tributyrinase and Lipolysis

This paper reports an investigation of the relation between both spontaneous and temperature-induced lipolysis and the concentration of tributyrinase in the milks of individual cows throughout their lactation periods.One of the purposes of this study was to provide additional information regarding factors which determine whether milk becomes rancid.Some investigators who have reported that the lipase content of milk is highest in late lactation and in winter have based their conclusions on what might be considered measurements of lipolysis rather than lipase, since variables other than lipase concentration may have been involved.Results reported by Mattick and Kay (7), Pfeffer et al. (8), Reder (9) and Roahen and Sommer (10) indicate that lipolytic enzymes in milk do not increase in winter or in late lactation.Tarassuk and Henderson (11) found that the development of spontaneous rancidity may be prevented by mixing susceptible milk with about four times its volume of normal milk within 1 hr.after milking.Tarassuk and Jack (12) reported that the lipasc of naturally lipolytically active milk adsorbs irreversibly on the fat globules when milk is cooled.Observations of Kelly ( 6) and Roahen and Sommer (10) are consistent with this report.