Levels of 24 minerals in local goat milk, its strained yoghurt and salted yoghurt (tuzlu yogurt)

The study was conducted to determine concentrations of 24 minerals including Ca, K, Mg, Na, P, S, Ag, Al, As, B, Ba, Cd, Co, Cu, Cr, Fe, Mn, Mo, Ni, Pb, Se, Si, Sr and Zn as well as gross chemical composition of salted yoghurt, strained yoghurt and the indigenous raw goats' milk by simultaneous inductively coupled plasma optical emission spectrometry (ICP-OES). Basic nutrient and mineral contents of raw milk increased significantly throughout manufacture of salted yoghurt (P < 0.001). Mean percentage of total solids, total protein, fat, ash and pH values for raw milk, strained yoghurt and salted yoghurt were: 12.32, 17.82, 28.41; 4.15, 8.31, 11.56; 4.37, 7.10, 10.45; 0.76, 0.79, 2.69; 6.68, 3.87, 3.95, respectively. Mean concentrations (ppm) for major minerals in raw milk, strained yoghurt and salted yoghurt were: 1342, 1455 and 2134 Ca; 823, 1052 and 1508 P; 510, 587 and 838 Mg; 296, 553 and 923 S; 409, 511 and 554 K; 433, 520 and 5147 Na, respectively. Of minor minerals B, Si, Se, Zn, Fe and Al were the most abundant in raw milk and its products. Except for As, toxic elements Cd, Ag, Pb (ppm) were 0.63, 0.28 and 0.06 for raw milk, 1.01, 0.29 and 0.11 for strained yoghurt, 1.00, 0.71 and 1.3 for salted yoghurt, respectively. Constituents in strained and salted yoghurts were influenced by the fermentation process, draining of yoghurt, cooking, salting and manufacturing utensils. This work also provided important information on safety and quality standards of local goats' milk, strained and salted yoghurts. (C) 2006 Elsevier B.V. All rights reserved.