Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.
2004
Volume 7
Issue 2
Topic:
Food Science and Technology
ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Domagała J. , Juszczak L. 2004. FLOW BEHAVIOUR OF GOAT’S MILK YOGHURTS AND BIOYOGHURTS, EJPAU 7(2), #09.
Available Online: http://www.ejpau.media.pl/volume7/issue2/food/abs-09.html

FLOW BEHAVIOUR OF GOAT’S MILK YOGHURTS AND BIOYOGHURTS

Jacek Domagała, Lesław Juszczak

 

ABSTRACT



Flow behaviour of yoghurts and bioyoghurts produced from goat’s unconcentrated milk at using different starter cultures was compared. Four starter cultures were applied to the production of yoghurts and four to the production of bioyoghurts too. Rheological properties were examined using rotary viscometer Rheotest 2 with controlled shear rate in coaxial cylinders system. Flow curves of yoghurts and bioyoghurts were assigned and described by Ostwald de Waele, Herschel-Bulkley and Casson models. An apparent viscosity was counted for shear rate 3 s-1. Generally, higher viscosity of yoghurts in comparison to bioyoghurts was stated. The yoghurts were generally characterised by higher value of consistency coefficient K and yield stress than bioyoghurts. The yoghurts have shown likewise higher deviation from Newtonian flow (lower values of exponent n) than bioyoghurts.

Key words: yoghurts, bio-yoghurts, goat´s milk, rheology..