Effect of whey protein concentrate,pH and salt on colloidal stability of acid dairy drink (Doogh) |
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| Authors: | Zahra Azary Ali Nasirpour |
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| Affiliation: | Department of Food Science and Technology, College of Agriculture, Isfahan University of Technology, Esfahan, Iran |
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| Abstract: | Serum separation of Doogh, an Iranian yoghurt drink, is a major problem. In this study, the effects of whey protein concentrate (WPC) addition, pH of the product and dissolved salt (sodium chloride) in milk on the colloidal stability of Doogh were investigated. By increasing the amount of WPC (from 0.5 to 3%) and salt in milk (from 0 to 1.6%), the serum separation decreased. Increasing pH values of sample (from 3.5 to 4.5), WPC (from 0.5 to 4%) and salt concentration in milk (from 0 to 2%) also increased the samples’ viscosity. All samples showed Newtonian behaviour except samples at pH 4.5, containing 4% WPC and 2% dissolved salt in milk. |
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| Keywords: | Acidified milk drink Doogh Colloidal stability Serum separation Whey protein concentrate Salt |
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