Thermal inactivation of lactoperoxydase, alkaline phosphatase and y-glutamyltransferase in camel milk

Abstract

Thermal inactivation of alkaline phosphatase (PAL), lactoperoxydase (LP) and y-glutamyltransferase (GGT) in camel milk was evaluated after heat treatment at the temperature range of 60 to 95°C during 30 s to 40 min. PAL was the most heat resistant, its activity in camel milk samples was still detectable after treatment at 85°C for 40 min. GGT was more heat sensitive than PAL, completely inactivated at 85°C after 2.5 min treatment. Likewise, the LP showed the highest heat sensitivity among the three enzymes studied; its total inactivation was at 80°C in less than 1 min. The use of a test involving lactoperoxydase would be the most suitable control method for the reliability of camel milk pasteurization.

Keywords

• Camel milk
• y-glutamyltransférase
• heat treatment
• lactoperoxydase
• alkaline phosphatase.