THE EFFECT OF FERMENTATION CONDITIONS ON THE NUTRIENTS AND ACCEPTABILITY OF TARHANA

A laboratory method was evaluated for the production of tarhana, a popular Turkish fermented wheat-yogurt mixture. The changes in pH, the total titratable acidity and the vitamin content (thiamine, riboflavin and vitamin B12) of tarhana of different formulations (type of wheat flour, amount of yogurt and presence of salt) were monitored during fermentation. Chemical composition and acceptability of laboratory-produced tarhana were compared with those of authentic homemade and commercially produced tarhana. The pH and titratable acidity of tarhana samples did not change after the third day in the course of a 4-day fermentation. The final pH and acidity (expressed as percent lactic acid) of tarhana were found to be in the range of 4.3-4.8 and 1.8-2.3 (dry basis), respectively. The thiamine, riboflavin and vitamin B12 contents of tarhana did not change considerably during fermentation. The addition of salt to tarhana lowered the acid formation rate during fermentation, leading to a higher pH. The replacement of white wheat flour with wholemeal flour resulted in an expected increase in the protein and vitamin content of tarhana; however, a decrease in overall acceptability was observed.