A comparison of selected quality characteristics of yoghurts prepared from thermosonicated and conventionally heated milks

• Published in: Food chemistry 2010-04, Vol.119 (3), p.1108-1113
• Main Authors: Riener, Joerg, Noci, Francesco, Cronin, Denis A., Morgan, Desmond J., Lyng, James G.
• Format: Article
• Language: English
• Subjects: food nutrient losses; food processing; food processing quality; gel strength; gelling properties; heat treatment; milk fat percentage; retrogradation; rheological properties; riboflavin; Sensory; sensory properties; Syneresis; temperature; texture; Thermosonication; thiamin; tocopherols; ultrasonic treatment; Viscosity; vitamin A; Vitamins; Water-holding capacity; Yoghurt; yogurt
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2009.08.025

Thermosonication (TS) of preheated (45 °C) milk (0.1%, 1.5% and 3.5% fat) for 10 min at an ultrasound frequency of 24 kHz allowed the preparation of yoghurts with rheological properties superior to those of control yoghurts produced from conventionally heated milk (90 °C for 10 min). Texture profile analysis and flow curves showed that yoghurts from the TS milks had stronger gel structures which displayed higher water-holding capacities (WHC) and lower syneresis. Based on averaged data from a sensory panel ( n = 30), TS yoghurts showed superior texture and colour properties and samples with a fat content of 0.1% scored best in terms of overall acceptability. Retentions of water-soluble (thiamine and riboflavin) and fat-soluble (retinol and tocopherol) vitamins were similar in TS and conventionally prepared yoghurts.