Physical properties of stirred yoghurt as influenced by the heating process of the milk.

摘要

This study investigated and compared the effects of different heating processes on physical characteristics of stirred yoghurt. Yoghurt milk was heated at 95.C for 256 s in batch mode and two continuous modes. In the continuous mode, milk was processed by an industrial pilot-scale heating system using indirect steam heating or direct steam injection heating. Physical properties, including graininess and roughness, of stirred yoghurt were determined during storage at 4.C for 14 days. The yoghurt made from batch treated milk had higher syneresis, storage modulus and yield stress than the yoghurt made from milk treated by indirect steam heating or direct steam injection heating. The yoghurt obtained from milk treated by indirect steam heating had lowest graininess, while the yoghurt obtained from milk treated by direct steam injection heating had highest visual roughness.