Analysis of some chemical and biological contaminants during wheat milling

ABSTRACT

Mycotoxigenic fungi, mycotoxins, pesticides and heavy metals were estimated in wheat, flour, bran, shorts and wheat germ. Samples were collected from different commercial milling lines in Great Cairo Governorate. Results showed that the most frequently isolated fungi were Aspergillus, Pencillium and Fusarium. The highest total fungal count was recorded in bran [14.3 x 10[-3] cfu] followed by shorts [11.9 x 10[3] cfu] and wheat germ [10.1 x 10[3] cfu] comparable with that of flour [3.1 x 10[3] cfu]. Nevertheless, the aflatoxins [AFs] were not detected in all collected samples. Ochratoxin A [OTA] was detected in 40%, 30%, 30%, 26.7% and 13.3% of bran, shorts, wheat germ, wheat and flour, respectively. The mean concentration of OTA in wheat was 4.15 ppb and it was 3 ppb in flour which considered lower than the permissible limits being 5 Pb. The obtained results indicated that heptachlor and o. p-DDE were the major pesticides contaminant in wheat and milling fractions and the highest mean level of heptachlor was detected in bran 0.017 ppm, whereas it was 0.033 ppm of o. p-DDE in shorts. The highest mean levels of lead [Pb] and cadmium [Cd] were found in shorts [0.482 and 0.097 ppm, respectively], while the lowest level of Pb [0.194 ppm] and Cd [0.034 ppm] were detected in flour