Daily Intake of Aflatoxin B1 and Ochratoxin a from Maize Grain (Zea mays L.) during the Storage with Lippia multiflora (Verbenaceae) and Hyptis suaveolens (Lamiaceae) Leaves in Côte d’Ivoire

The aim of this study was to monitor the sanitary quality during the storage of maize grains in polypropylene bags for 9 months containing leaves of Lippia multiflora and Hyptis suaveolens and to assess the risk of exposure to aflatoxin B1(AFB1) and ochratoxin A (OTA) with and without the treatment. This study was carried out in the villages of Timbé and Soko, respectively, in the departments of Katiola and Bondoukou of Côte d'Ivoire from June 2014 to February 2015. The parameters determined were the Estimeted Daily Intake (EDI) of AFB1, OTA and the risk of exposure. The batches treated with Lippia multiflora and Hyptis suaveolens had low levels of EDI and exposure risks compared to controls independently of the study site. The leaves of Hyptis suaveolens had a biopesticide effect much greater than Lippia multiflora leaves and the mixture of leaves of the two plants. Indeed, the mycotoxin levels of the control batches varied between 0.05 ± 0.00 and 75.97 ± 1.83 ng / kg body weight / day for AFB1 and between 0.36 ± 0.00 and 57, 72 ± 1.63 ng / kg body weight / day for OTA in both localities. These values of the control batches reflect a real and high risk of exposure from 2 months of storage. For experimental batches, EDI values ranged from 0.05 ± 0.00 to 15.34 ± 0.80 ng / kg body weight / day for AFB1 and from 0.36 ± 0.00 to 7.42 ± 0.65 ng / kg body weight / day for OTA. The risks of exposure become real only after 7 months of storage. After 7 months, the leaves of Hyptis suaveolens used individually were the most effective, followed by the leaves of Lippia multiflora and finally the leaves from the two plants.

These results indicate that the treatment of maize with the leaves of Lippia multiflora and Hyptis suaveolens inhibits insect and fungal activity and preserves the quality of the grains as well as the very low maintenance of the risk of exposure to AFB1 and OTA up to 7 months. This inexpensive and easy-to-use treatment should be popularized among farmers to strongly decrease the exposure risk.