Influence of enzymatic treatment on stabilization of traditional Iranian yoghurt drink, Doogh

Doogh is an Iranian fermented milk drink prepared through adding water and salt to yoghurt. In this study the effect of enzyme transglutaminase on Doogh characteristics was investigated. Also, the influence of two preparation methods i.e. water addition to yoghurt as a common methodand fermentation of diluted milk as an alternative was studied. The enzyme was applied into the skim milk either before or after pasteurization followed by its thermal inactivation. Doogh preparation directly from milk resulted in more stable products with less phase separation. Enzymatic treatment after pasteurization of milk followed by water addition and fermentation yielded the least phase separation during storage. Improvement of the stability of Doogh samples was associated with increase in the apparent viscosity and uniformity of particles accompanied by finer meshed network and smaller pores in their microscopic structure.

کلیدواژه ها:

component: Doogh ، Transglutaminase ، Stability ، Viscosity ، Microscopy