Trace elements in foods and meals consumed by students attending the faculty cafeteria

The content and intake of some trace elements (Pb, Cd, Ni, Hg, Cr) in meals, consumed by students attending the Faculty Cafeteria, were assessed. The study was carried out over 6 days of the 2nd week of February, 1993 and in three consecutive days of the second week of May. In those periods 10453 and 4055 students attended the cafeteria, respectively. After recording the ingredients and the preparation and cooking methods, some edible portions of foods and dishes were collected, homogenised, lyophilised and kept in polyethylene bottles until analysis. We found few differences in food content and dietary intake of some (Ni and Cr) but not all trace elements between February and May. Higher levels of Pb, Cd, Ni, Cr were present in bread (21.5+/-14.0, 5.6+/-0.02, 55.6+/-1.7 and 66.9+/-0.1 microg/100 g of edible portion, respectively), followed by meat, filled pasta and cheese, whereas lower values were observed in vegetables and fruit. The highest Hg content was recorded in the pasta group. Among the most frequently consumed foods and meals, the highest levels of P, Pb, Cr, Hg, Ni were found in bread, meat and pasta. The calculation of mean trace element intake, corrected for leftovers, showed pasta, bread and meat as the main sources of Pb, Cd, Ni, Hg and Cr over the two periods. The estimated potential tolerated weekly intake (PTWI) resulted high for Pb and Cd and low for Hg. Finally, a large variability in trace element content between raw and cooked foods was observed. These results give valuable information on trace element content of foods to be used for preparation of meals at the Faculty cafeteria in different seasons.