HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bienvenue, A. Articles by Singh, H. Search for Related Content PubMed PubMed Citation Articles by Bienvenue, A. Articles by Singh, H.

Rheological Properties of Concentrated Skim Milk: Importance of Soluble Minerals in the Changes in Viscosity During Storage

Dairy Products Technology Centre, California Polytechnic State University, San Luis Obispo, CA 93407

Corresponding author: R. Jiménez-Flores; e-mail: rjimenez{at}calpoly.edu.

Properties of condensed milks prior to spray drying dictate to a large extent the functionality of the resulting milk powder. Rheological properties of concentrated skim milk, with total solids content of 45% but different mineral content, were studied as a function of shear rate and storage time at 50°C. These milks are proposed as a model to study the effects of minerals on rheology and age gellation of condensed milk prior to drying. During storage of the concentrated milk, the apparent viscosity, particularly after 4 h, increased markedly at all shear rates studied. The yield stress also increased steeply after 4 h of storage at 50°C. The changes in apparent viscosity of concentrated milk stored for up to 4 h were largely reversible under high shear, but irreversible in samples stored for longer time. The appearance of yield stress suggested the presence of reversible flocculation arising from weak attraction between casein micelles, with a transition from reversible to irreversible aggregation during storage. Particle size analysis confirmed irreversible aggregation and fusion of casein micelles during storage. Gradual reduction of mineral content of concentrated milks resulted in a marked decrease in the apparent viscosity and casein micelle aggregation during storage, while addition of minerals to milk had the opposite effect. The results demonstrated that the soluble mineral content is very important in controlling the storage-induced changes in the rheology of concentrated milks.

Key Words: concentrated milk • yield stress • casein micelle aggregation • mineral environment

Abbreviation key: PIDS = polarization intensity differential scattering

This article has been cited by other articles:

				A. O. Karlsson, R. Ipsen, K. Schrader, and Y. Ardo Relationship Between Physical Properties of Casein Micelles and Rheology of Skim Milk Concentrate J Dairy Sci, November 1, 2005; 88(11): 3784 - 3797. [Abstract] [Full Text] [PDF]