Influence of Particulated Whey Protein Concentrate on the Rheological and Sensory Properties of Low Fat Yoghurt.

Abstract

The present work is concerned with the manufacture of low fat yoghurt using particulated whey protein concentrates (PWPC) as fat replacer. Experimental yoghurts milk contained 3.0% fat (control), 2% fat +10% PWPC, 1% fat + 20% PWPC and skim milk + 30% PWPC, were prepared and their rheological and sensory attributes were followed.The results indicated that increasing shear rate significantly reduced the apparent viscosity of low fat yoghurt. Increasing rate of fat replacement with PWPC reduced viscosity values of yoghurt compared with control. Viscosities of all yoghurt samples increased during storage. Low fat yoghurt made with 10 and 20% PWPC showed similar firmness and syneresis of the control, and had good flavour when fresh and after 2 weeks of storage while, yoghurt with 30% PWPC resulted in too firm body and gave an undesirable flavour. Substituting milk fat with PWPC up to 20% in milk can produce good quality low fat yoghurt.