Power ultrasound affects physicochemical, rheological and sensory characteristics of probiotic yoghurts

The effect of ultrasound (US) on milk fat globule (MFG) size and some quality properties of set-type probiotic yoghurt produced with skim milk powder (SMP) or caseinate and whey protein concentrate (CWPC) was compared with conventional homogenisation. US reduced MFG size up to 46.5% compared with conventional homogenisation; the best homogenisation efficiency with the smallest MFG size was obtained with 400 W US for 15 min. The lowest fermentation time was observed in the probiotic yo-ghurts produced with CWPC and single-stage ultrasonication. US improved water holding capacity in all yoghurts, but increased the apparent viscosity in only the groups enriched with SMP. Probiotic yoghurts produced with single or double-stage ultrasonication gave taste, odour, and appearance scores similar to those of the controls, while texture and overall acceptability scores of yoghurts produced with SMP and single-stage ultrasonication were higher than those of the control on the 14th day of storage.(c) 2022 Elsevier Ltd. All rights reserved.