Abstract:Aflatoxin B 1 (AFB 1 ) and ochratoxin A (OTA) are contaminants which co-occurred in the same food such as cereals. The few studies performed on their interactive effect had revealed additive or antagonistic cytotoxic effect according to cells endpoints and concentrations of both mycotoxins. The aim of the present study was to investigate in a possible influence of very low level of ochratoxin A in aflatoxin B 1 toxic action regarding cellular endpoints such as malonedialdehyde (MDA) production and cells viability as evaluated by lysosome and mitochondria integrities and cell lactate dehydrogenase (LDH) leakage. OTA (20nM) and AFB 1 were tested in combination in both human intestinal (Caco-2) and hepatoma (HepG2) cells lines. As results, OTA alone tested at 20nM was not cytotoxic and did not induce MDA production in both Caco-2 and HepG2 cells line. Interestingly, combined to AFB 1 (10µM), OTA enhanced markedly AFB 1 cytotoxic effect. OTA significantly increased cell lysosomes damage induced by AFB 1 from 24% to 38% (+14%) and from 28% to 43% (+15%) respectively in Caco-2 and HepG2 cells line (p<0.05). Similarly, OTA enhanced inhibition of mitochondria succinate dehydrogenase activity induced by AFB 1 until to +15% and +6% respectively in Caco-2 and HepG2 cells line (p<0.05). On cell necrosis marker, the mixture of OTA and AFB 1 induced more LDH leakage when compared to AFB 1 alone with increase of +14% and +12% respectively in Caco-2 and HepG2 cells line (p<0.05). Finally, on MDA production, AFB 1 + OTA induced more intensively MDA production when compared to AFB 1 alone with +49% and +110% of increasing in both Caco-2 and HepG2 cells line (p<0.01). Taken together, our results suggested that combined AFB 1 and OTA induced all the toxicities observed with the mycotoxins separately but more intensively suggesting synergistic or potentiating effect. Moreover, AFB 1 or its association with OTA had been found very potent in human hepatic cells HepG2 in necrosis induction but especially in lipids oxidative damage confirming oxidative stress as one of keys pathways in toxic action of AFB 1 .

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The aim of our study was to evaluate physical properties of cashew nuts from the three main production areas in Côte d'Ivoire namely Bondoukou, Dabakala and Mankono after 6 months of storage in identical conditions. Sample cashew nuts have been collected from farmers randomly selected in 20 localities far enough apart and also veritable purveyors of nuts. The physical traits of the raw cashew nuts and their different parts were evaluated by standard methods. As results, our data showed that despite the similar mass (in mean 6.23 g) of cashew nuts independently of the origin, the mass of the kernels nuts from Bondoukou (2.17 g) were significantly higher than those from Dabakala (1.90 g) and Mankono (1.81 g) respectively in contrast to the shell mass indicating the best kernels yield at Bondoukou. Nuts water content diminished slowly from nuts at Bondoukou (3.86%) but rapidly at Mankono (5.68%) after 6 months of storage. For the morphometric characteristics, our results revealed that the nuts from Bondoukou were statistically shorter but the kernels were thicker (15.1 ± 0.50 mm) versus and for Dabakala (11.4 ± 0.16 mm) and Mankono (11.2 ± 0.19 mm) respectively. There is a clear correlation between the arithmetic diameter of the kernels and their sphericity (r = 0.99). Concerning the technological properties, out-turn was average ranged from 44.09 to 46.69 with defective up to 18% at Dabakala. Taken together, our results suggested that the cashew nuts presented different physical properties according to each region of production in Côte d'Ivoire requiring appropriated agricultural practices.

Improving the quality of agricultural products depends largely on production process. In the absence of data on farmers' practices and the average quality of cashew nuts in Côte d'Ivoire, the present study aimed to provide a detailed description of the cashew nut production process. Thus, a survey was carried out in the zones of Mankono, Dabakala and Bondoukou among 386 cashew producers selected at random and interviewed using the face-to-face technique. The results revealed that intercropping was practiced in cashew cultivation (42% -62% of the producers), modern cultivation technique (72% -98% of the producers) but with rare use of selected seeds (8% -20% of the producers), labour/ha during nut harvesting (2.6 -12 workers/ha). Concerning the harvesting process, the time taken to pick the nuts varies from 1 to 14 days; the use of pesticides during harvesting (14% to 97% of the producers) and the absence of sorting of the nuts in 42% of the Mankono producers justify the probable conservation of defective and immature nuts in their production. For drying, the main dryers were the slatted table, the cemented surface and the tarpaulin, but other dryers were found such as the mosquito net, the propylene rice bag, the fertiliser bag and the black bag. Generally, the drying time of cashew nuts was very short: 2 days (43% -77% of the producers interviewed) but surprisingly 1 day (7% -27% of the producers interviewed). For Mankono, the use of chemicals was permanent during all stages of the cashew production process. Overall, the results suggest the need to assess the real impact of farmers' practices on the quality of cashew nuts from Côte d'Ivoire.

Abstract:The conservation of fresh kolanuts produced in Côte d'Ivoire and intended for the export, poses a veritable problem for the farmers. After 2 or 3 months of storage, the stock of kolanuts dramatically diminished occasioning high loss of economic resources. The aim of the present study was to find strategies for the best conservation for long period by investigation in appropriated nature of container, temperature of storage and in a possible fungicide adequate for kolanuts. Three (03) containers namely traditional made from the leaves of Thaumatococcus daniellii (Benn.) Benth., polyvinyl chloride (PVC) container and perforated cardboard have been studied. The temperatures of storage investigated were 26°C and 29°C while epoxiconazole is used as the fungicide. Fungi and Ochratoxin A (OTA) occurrence have been taken as bio-indicators of kolanuts healthy. Fungi were isolated by using Potato Dextrose Agar (PDA) and standard laboratory methods while OTA was extracted with a methanol/3% sodium hydrogen carbonate solution and purified using an immunoaffinity column prior to HPLC analysis with fluorescence detection. As results, the best temperature of storage could be 26°C and the container PVC had been found more efficient in fungi reduction in kolanuts when compared to traditional container made from leaves of Thaumatococcus daniellii (Benn.) Benth. In addition, OTA levels are stayed lows after 10 months of kolanuts storage. Moreover, the fungicide epoxiconazole was able to prevent Aspergillius flavus proliferation and retarded both Penicillium sp. contamination and OTA secretion in kolanuts until 6 months of storage. Taken together, the results suggested that a combination of the using of PVC container and fungicide epoxiconazole and 26°C as temperature of storage could improve significantly the conservation of fresh kolanuts for several months.