Evolution of Mycotoxins during Maize Grains Storage in Triple Bags Containing Plants Biopesticides (Lippia multiflora and Hyptis suaveolens)

Abstract

In Côte d’Ivoire, maize plays an essential role as subsistence, commercial and socio-cultural culture. To consume good quality corn, it is necessary to preserve the sanitary quality through a good storage method. The aim of study was to evaluate sanitary quality of stored maize in triple bags containing plants biopesticides. Maize grains were collected in March 2016 in the north of Côte d’Ivoire. The fresh leaves of Lippia multiflora and Hyptis suaveolens were collected and dried in sunlight for 7 days in the center of Côte d'Ivoire. Triple bags were bought in Abidjan market. All this material was sent to the Laboratory of Biochemistry and Food Sciences, Félix Houphouët-Boigny University, Côte d’Ivoire, to perform the experiment. A central composite design was used for sample constitution. Ten treatments were obtained for the experimentation. The first treatment was conservation of 50 kg of maize grain in a polypropylene bag. The second treatment was conservation of 50 kg of maize grain in a triple bag. The other eight treatments were carried out with PICS bags each containing 50 kg of maize grain and different proportions of chopped leaves Lippia multiflora and Hyptis suaveolens. Thus, a control group with polypropylene bag (TPPB0), a control group in triple bag without biopesticides (TPB0) and 8 experimental lots of triple bags noted TB1 containing 0.625kg L. multiflora and 0.625kg H. suaveolens, TB2 with 0.40 kg of L. multiflora and 1.60 kg of H. suaveolens, TB3 with 1.60 kg of L. multiflora and 0.40 kg of H. suaveolens, TB4 with 0.10 kg of L. multiflora and 0.40 kg of H. suaveolens, TB5 with 0.40 kg of L. multiflora and 0.10 kg of H. suaveolens, TB6 with 2.5 kg of L. multiflora and 2.5 kg of H. suaveolens, TB7 with 1.25 kg of L. multiflora and TB8 with 1.25 kg of H. suaveolens have been used. The contents of moisture, water activity, aflatoxin B1 (AFB1), ochratoxin A (OTA), fuminosin B1 (FB1) and zearalenone (ZEA) were studied. The levels of AFB1, OTA, FB1 and ZEA resulted from maize grains treated with biopesticides were significantly lower than those recorded with untreated maize of control bags. The results show AFB1 levels (from 4.17 ± 0.05 to 5.15 ± 0.06 μg/kg), OTA levels (from to 4.58 ± 0.25 to 6.10 ± 0.01 μg/kg), FB1 levels (from 4.96 ± 0.07 μg/kg to 7.42 ± 0.06 μg/kg) and ZEA levels (from 4.66 ± 0.10 μg/kg to 8.78 ± 0.14 μg/kg). Maize samples stored in triple bagged bags with different proportions of biopesticide were significantly lower than those recorded in the polypropylene woven sample bag (TPPB0) and in the triple bagged control bag (TPB0) during the storage period. Storage of maize grains in triple bags with the leaves of L. multiflora and H. suaveolens appears as a method of effective and inexpensive conservation to ensure the sanitary quality of maize. This inexpensive and easy-to-use treatment should be popularized among farmers.