Fortification of Stirred Yogurt with Certain Microelements Using Natural Sources.

The present study is concerned the fortification of stirred yogurt with certain microelements to improve its nutritional value. The normal stirred yoghurt and stirred yoghurt fortified with 5 % oats, mango, banana fruits, or strawberry jam were prepared .The impacts of fortification on physicochemical characteristics of yogurt fortified with some microelements (silicon, iron, manganese, zinc and copper) were investigated. The results revealed that pH value increased with the increase of added oats and decreased with the fruit addition. Advancing storage period decreased pH values and slightly increased total solids in all samples. Data also showed decrease in protein content, while an increase in the contents of fat, fiber and carbohydrate of the fortified stirred yoghurt. Mineral analyses showed pronounced differences in the total microelements content between the normal stirred yoghurt and stirred yoghurt with oats and fruits. The microelements contents of stirred yoghurt with oats or fruits as ppm were in the range: Silicon (28.70- 36.50), manganese (4.60-5.25), iron (3.50–4.10), zinc (3.30-3.60). Concerning the natural stirred yoghurt the values obtained (in ppm): silicon (14.70), manganese (0.90), iron (0.70) and zinc (3.60). However, copper was not detected in all treatments. Concerning the sensory evaluation, addition of fruits improved flavor and total acceptability. Therefore, using oats is recommended as a good natural source to fortify yoghurt with silicon, manganese and iron in making good nutraceutical stirred yoghurt.