Effect of transglutaminase on the quality of stirred yoghurt

The crosslinking of milk protein by transglutaminase,so it was applied in yoghurt processing to improve texture properties.The enzyme was added to yoghurt-milk at different production steps(inactive enzyme and not inactive enzyme) at 0.2g/L milk.The optimum adding method of transglutaminase was decided through the change of hardness,water holding capacity,the rheological characteristics,starter bacteria and comprehensive sensory evaluation.The result showed that two treatment methods of enzyme could reduce the post acidification of yoghurt during storage,improve hardness,water holding capacity and shearing stress.TGase was added together with starter culture could improve the physical and chemical properties more significantly(p0.05).Compared with the control group,haedness had the maximum and increased 8.48g in the first 21 days.With storage time increasing,water holding capacity was increased,an increase of 5.41%.As a result of the residual activity of TGase drastically reduced during yoghurt storage,had no passive effect on yogurt quality.This method did not require additional enzyme reaction time,the heat treatment step and equipment.So it was the best way to acquire economic benefits.