Relationship between smoothing temperature, storage time, syneresis and rheological properties of stirred yogurt

Six different smoothing temperatures were compared for nonfat yogurt and the changes in syneresis and rheological properties observed for up to 22 days. Multiple linear regressions were used to describe the syneresis, firmness, flow time, viscosity, and flow resistance and the relationship between these properties, the smoothing temperature and the storage time. During storage, viscosity, firmness, and flow time increased; syneresis and flow resistance remained stable. Syneresis increased significantly (P < 0.05) with smoothing temperature (10-35 degrees C). Other properties increased slightly (P > 0.05), and properties started to decrease above 30 degrees C. Syneresis, viscosity, and flow resistance were more sensitive to smoothing temperature; firmness and flow time were more sensitive to storage time. Lower smoothing temperature (10 degrees C) should be used to minimize syneresis while smoothing temperature ranging from 25 to 30 degrees C is better to improve rheological properties. Storage time must be considered to optimize these properties. Crown Copyright (C) 2020 Published by Elsevier Ltd. All rights reserved.