| Abstract | The aim of the present study was to investigate the possible bio-transformation of 1 mg/kg of sodium selenite (Na2SeO3) by yoghurt culture to organic form(s) during Kareish cheese making and use of its whey byproduct in bread making. Addition of 1 ppm Se(IV) had no significant effect on the bacterial growth during 24 hrs of incubation in whey media at 40?C. The inorganic selenium was completely bio-converted to organic form(s) after 4 hrs of incubation. The whey and cheese of Se-fortified milk had significantly higher Se content (300 and 6000 ppb, respectively) compared to control (0 and 102 ppb). Partial or complete replacement of water (control) with Se-whey increased the organic selenium content in the bread from 0 ppb (control) to 35, 73, 146 and 195 ppb bread fortified with 25, 50, 75 and 100% Se-whey respectively. Addition of whey had no significant deleterious effect on the doughs raising ability made from low or high quality flours. However, increasing the level of whey gradually increased the dough hardness and slightly decreased bread volume and density. Chemical analysis showed a gradual decrease in bread acidity, and increases in total solids, calcium, potassium and phosphorus contents of bread with increasing the added level of whey. No noticeable differences were found in overall acceptability between bread made with or without added Se-whey. In conclusion, these findings could be applied in the manufacture of yoghurt, Kareish cheese and bread enriched with organic selenium. Besides improving the nutritional and biological quality of such products, utilization of whey can reduce the environmental pollution from dairy industries. |