Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-05T13:48:12.673Z Has data issue: false hasContentIssue false

Effect of temperature and/or pressure on lactoperoxidase activity in bovine milk and acid whey

Published online by Cambridge University Press:  16 April 2002

LINDA R. LUDIKHUYZE
Affiliation:
Department of Food and Microbial Technology, Laboratory of Food Technology, Faculty of Agricultural and Applied Biological Sciences, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, B-3001 Heverlee, Belgium
WENDIE L. CLAEYS
Affiliation:
Department of Food and Microbial Technology, Laboratory of Food Technology, Faculty of Agricultural and Applied Biological Sciences, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, B-3001 Heverlee, Belgium
MARC E. HENDRICKX
Affiliation:
Department of Food and Microbial Technology, Laboratory of Food Technology, Faculty of Agricultural and Applied Biological Sciences, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, B-3001 Heverlee, Belgium

Abstract

At atmospheric pressure, inactivation of lactoperoxidase (LPO) in milk and whey was studied in a temperature range of 69–73 °C and followed first order kinetics. Temperature dependence of the first order inactivation rate constants could be accurately described by the Arrhenius equation, with an activation energy of 635·3±70·7 kJ/mol for raw bovine milk and 736·9±40·9 kJ/mol for diluted whey, indicating a very high temperature sensitivity. On the other hand, LPO is very pressure resistant and not or only slightly affected by treatment at pressure up to 700 MPa combined with temperatures between 20 and 65 °C. Both for thermal and pressure treatment, stability of LPO was higher in milk than in diluted whey. Besides, a very pronounced antagonistic effect between high temperature and pressure was observed, i.e. at 73 °C, a temperature where thermal inactivation at atmospheric pressure occurs rapidly, application of pressure up to 700 MPa exerted a protective effect. At atmospheric pressure, LPO in diluted whey was optimally active at a temperature of about 50 °C. At all temperatures studied (20–60 °C), LPO remained active during pressure treatment up to 300 MPa, although the activity was significantly reduced at pressures higher than 100 MPa. The optimal temperature was found to shift to lower values (30–40 °C) with increasing pressure.

Type
Original Article
Copyright
Proprietors of Journal of Dairy Research 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)