The Milk Lipase System. II. Effect of Formaldehyde

Abstract
The inhibitory effects of formaldehyde on the lipase system of cows milk were studied with respect to time and concentration of inhibitor. By proper control of conditions, the pH optimum of most of the individual lipases could be selectively revealed. Prolonged incubation nullified this effect due to reversibility of the inhibition. Addition of formaldehyde 30 minutes after the initiation of incubation also nullified its inhibitory power. Formaldehyde was found to act as a competitive inhibitor at pH 6.2. The data support the view that milk contains more than one lipase.