Microbiological, Physicochemical, Organoleptic and Rheological Characteristics of Bulgarian Probiotic Yoghurts Obtained by Ultrafiltration of Goat’s Milk

In this experimental work, the microbiological, physicochemical, organoleptic and rheological characteristics of probiotic Bulgarian yoghurts produced by ultrafiltration of goat’s milk using different volume reduction ratio (2 and 3) and several probiotic starters (MZ2f, MZ2f + Bifidobacterium bifidum BB – 87, MZ2f + Lactobacillus acidophilus LAB – 8) were studied. It was established that the dry matter, protein, fat contents, the number of lactic acid bacteria, titratable acidity and the dynamic viscosity increased and the pH decreased with the rise of volume reduction ratio during ultrafiltration. All yoghurts exhibited Bingham plastic flow behavior. We recommend to use a volume reduction ratio of 3 and MZ2f + Bifidobacterium bifidum BB – 87 to produce probiotic Bulgarian yoghurts with the highest dry matter, protein, fat contents; counts of viable lactic acid cells, viscosity and the best sensory characteristics in the range of this experiment.