Tarhana as a traditional Turkish fermented cereal food. Its recipe, production and composition

As a fermented product tarhana is the dry form of yogurt-cereal mixture and represents an important part of the diets of many people in Turkey. It is prepared by mixing wheat flour, yogurt, yeast and a variety of cooked vegetables (tomatoes, onions, green pepper etc.), salt, and spices (mint, paprika) followed by fermentation for one to seven days. Generally one part yogurt is mixed with two parts of wheat flour (w/w). In commercial production there are two methods for tarhana making. First method is called straight method and ingredients in the recipe is mixed and kneaded, fermented, dried and finally sieved. Second method is called sour dough method that contains three steps, each one has a different recipe. Throughout fermentation lactic acid bacteria and yeast give the characteristic taste and flavour of tarhana by producing lactic acid, ethanol, carbondioxide and some other organic compounds. Organic acids composed in fermentation period lower the pH (3.4-4.2), and low moisture content (6-10%) is a poor medium for pathogens and spoilage organisms. The nutrient content of tarhana depends upon yogurt and flour ratios as well as some other ingredients, and it is also considered to be a useful high-protein dietary supplement with average 15% protein content. Addition of set yogurt due to high dry matter content and baker's yeast increase protein content and enhances it's amino acid composition.