International Journal of Food Science and Nutrition

Authors
Okoronkwo KA, Opara CN

Abstract
The occurrence of toxic substances in some regular food seasonings was studied as well as their microbial loads and antimicrobial activities. Five branded seasonings were used including: Benny, Curry, Thyme, Onga and Kitchen glory. Anti-nutrients content, heavy metal contents and microbiological assessments were done. Results obtained shows that there were some toxic substances in the seasonings at varying concentrations. Alkaloid was in the range of 0.04% (Kitchen glory) to 0.07% (Thyme), Phenol ranges from 0.04% (Kitchen glory) to 0.36% (Thyme) while others ranges from 0.12% (Benny) to 0.25% (Curry) and from 0.11% (Benny) to 0.36% (Thyme) respectively. Hydrogen cyanide was detected at very low concentration ranging from 0.56mg/kg in Curry to 7.96mg/kg in Kitchen glory. The variation in the anti- nutrients of the seasonings were found to be significantly different (p<0.05). Other toxic substances detected in the seasonings were heavy metals at different levels including Iron (0.07 to 1.92mg/100g), Zinc (2.23 to 12.7mg/100g), Copper (0.07 to 0.69mg/100g), and Manganese (0.01 to 0.67mg/100g) and lead (0.00 to 0.27mg/100g). The microbial load of the seasonings varied significantly (p<0.05) from 8.67x 103cfu/g to 17.00x 103cfu/g of bacteria while the fungal load varied from 0.00 to 2.00x l01cfu/g. The extracts of the seasonings shows varying levels of antimicrobial activity against some bacteria and fungi. Inhibition of bacteria by the seasoning extracts had diameters of inhibition zone ranging from 0.00mm (no inhibition) by Onga extracts to 11.33mm by extract of Thyme on Staphylococcus aureus, inhibition of Bacillus Subtilis was in the range of 8.00mm (Onga) to 13.67mm (Thyme) while Pseudomonas aureginosa was inhibited from 6.67mm (Onga) to 13.33mm (Thyme). Yeast inhibition was highest with Curry extract (10.33mm) and least with Onga extract (6.67mm). The corresponding values for Aspergillus niger was 11.67mm (Thyme) and 6.33mm (Onga) and Kitchen glory. It was concluded that the toxic substances in the regular seasonings included anti-nutrients and heavy metals as well as some bacteria and fungi with potentials of toxic production and some health hazard. There were significant variation (p<0.05) in the levels of the toxic substances in the seasonings.