Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-07T03:33:08.282Z Has data issue: false hasContentIssue false

Spoilage patterns of skim and whole milks

Published online by Cambridge University Press:  06 September 2002

HILTON C. DEETH
Affiliation:
School of Land and Food Sciences, The University of Queensland, Gatton Campus Gatton Qld 4343, Australia
TATIK KHUSNIATI
Affiliation:
School of Land and Food Sciences, The University of Queensland, Gatton Campus Gatton Qld 4343, Australia Current address: Microbiology Dept, Indonesian Institute of Science, JLN IR H Juanda No. 18, Bogor, Indonesia.
NIVEDITA DATTA
Affiliation:
School of Land and Food Sciences, The University of Queensland, Gatton Campus Gatton Qld 4343, Australia
ROBERT B. WALLACE
Affiliation:
School of Land and Food Sciences, The University of Queensland, Gatton Campus Gatton Qld 4343, Australia

Abstract

The reason for the reported difference in spoilage behaviour of skim and whole pasteurised milks was investigated. The rates of growth of psychrotrophic bacteria were not significantly different in the two milks and the bacterial types, all pseudomonads, present at spoilage were also similar. However, when representative spoilage organisms were cultured into freshly pasteurised skim and whole milks, skim milks exhibited predominantly bitter flavours while whole milk showed mostly sour flavours. The different spoilage behaviours can be largely explained by greater proteolysis in skim milk than in whole milk, caused by higher production of protease and greater susceptibility of the protein to protease attack. In addition, lipolysis in whole milk, caused by the substantial quantities of lipase produced by spoilage pseudomonads in this milk, also contributes to the different flavours produced during cold storage of these milk types.

Type
Research Article
Copyright
© Proprietors of Journal of Dairy Research 2002

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.)