The Effect of the Contaminated Starter with Yeast on the Quality of the Kurdish Fermented Milk (Mast)


Anwar H.L Ali, Stara Kader, & Hayder M. Hamzah

College of Agriculture, University of Sulaimani, 2 College of Science, University of Sulaimani


Abstract
Mast is the type of set yoghurt manufactured in Kurdistan, it is firm fermented milk, characterized
by yeasty, sharpen acidity and fir m consistency. Applying the same traditional method by using local mast in
the Sulaimani city as starter which contains lactic acid bacteria with contaminated yeasts. The starters were
divided into four parts, the first one was the control and the other three parts were treated with heat in water
bath for (60°C/10 minute, 65°C/10 minute and 65°C/20 minute) respectively. The experiment reported that
the control (untreated starter) have the highest yeast cells count (100%), and the starter treated with 65°C/20
minute have the lowest yeast cells count ( 0.3%). The starter treated with 65°C for 10 and 20 minute
produces best mast quality according to the sensory test in comparison with other treatments.

Keywords: Fermented milk, heat treatment, lactic acid bacteria, yeast.

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