Natural occurrence of heavy metal, fungi and mycotoxins in soybean meal samples used in animal feeding in Saudi Arabia

Abstract

20 samples of soybean meal used in animal feeding in Saudi Arabia were analyzed for their content of heavy metals and contamination with fungi and/or their mycotoxins. The analyzed heavy metals were lead, copper, cadmium, nickel, chromium, arsenic and mercury, which were detected using Atomic Absorption  Spectrometer. The data shows that cadmium levels in soybean meal were higher in four samples when  compared to the Current European Official Regulations. The amount and generic composition of microscopic fungi in feeding soybean have been monitored. Total counts of fungi were ranged from 3.9x10⁴ to 10⁵ CFU/g. From the analyzed samples, 36 species belonging to 16 genera of microscopic fungi were isolated and  identified. Among the isolated genera, Aspergillus, Fusarium and Penicillium belonged to the most dangerous fungi. The level of mycotoxins detected in feeding soybean was ranged from 1 to 14.8 ppb for aflatoxins, 1 to 14 ppb for ochratoxin A and 1 to 17 ppb for zearalenone. In conclusion, feeding soybean can be seriously  contaminated by heavy metals, mycotoxigenic fungal genera as well as mycotoxins that cause serious health problems for man and animals.

Key words: Aflatoxins, ochratoxins A, zearalenone, mycotoxins, heavy metal, soybean.