Influence of Mastitis on Properties of Milk XI. Fat Globule Membrane

Abstract

The effect of mastitis on the milk ~at globule membrane of milk samples from individual quarters was investigated. Wis- consin Mastitis Test positive (>20mm) milk contained appro ".xi~ately 10% less milk fat globule membrane material than negative ( < 10tuna) milk. The lipid por- tion of the milk fat globule membrane preparation from positive milk contained smaller amounts of phospholipids and larger amounts of cholesterol. Milk fat globule membrane preparations from positive milk had higher aldol~se activity and lower xanthine oxidase activity. Dis- sociated membrane protein prepared from positive milk was resolved into five components by polyacrylamide gel elec- trophoresis while the membrane protein prepared from negative milk was re- solved into three components.