Cotton and polyester fabrics are treated with radio-frequency plasma (in air) at different power levels and time intervals, and moisture content and surface resistivity behavior are investigated. Plasma treatment lowers the moisture content of cotton and enhances that of polyester. The surface resistivity of plasma treated cotton is affected by both power level and treatment time, and the surface resistivity of polyester is dramatically reduced after plasma treatment. The two fabrics are subjected to further plasma initiated grafting of acrylamide and acrylonitrile. Polyester has a moisture con tent of up to 3% after plasma initiated grafting. The surface resistivity of cotton is somewhat lowered, whereas that of polyester is drastically lowered after grafting.

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Water sorption test of coffee (Arabusta) powder carried out under laboratory conditions are presented together with mathematical analyses of the moisture adsorption isotherms. Coffee powder moisture adsorption isotherms were determined within the range of 0.07-0.97 water activity at 29°C, using saturated salt solutions dynamic method. Sorption isotherms of coffee powder have a sigmoid sharp (type II). The data obtained were fitted to several models of two-parameter (BET, Hasleys, Kuhn, Chung and Pfost, Freundlich and Oswin) and three-parameter (GAB). A non-linear least square regression analysis was used to evaluate the models constants.In relation to the isotherm models the best models were Halsey (in the wide range of water activity) and Kuhn (in the range of water activity 0.07-0.5) obtaining minor values of % mean relative errors and higher correlation coefficient. Critical value of equilibrium moisture content of coffee powder corresponding to the aw equal to 0.6 was 34.6 g water per 100 g dry matter. These values are useful for storing conditions optimisation from the point of view of microorganisms growth and structural changes analyses. The monolayer moisture content values for BET were higher than those for GAB, these values are 22.14 and 2.57 g water per 100 g dry matter, respectively.

A b s t r a c t A r t i c l e I n f oThe objective of this work was to determine the occurrence of mycotoxins like aflatoxin B1and ochratoxin A in a few foodstuffs consumed by the Ivorian population. The levels of AFB1 are higher than the contents of OTA. Dry gumbo is the most contaminated food in AFB1 with an average grade of 71.18 μg/kg. Adjovan has an average AFB1 concentration of 64.65 μg/kg. The levels of AFB1 of cassava are on average 4.17μg/kg. Dried maize is the least contaminated commodity with an average concentration of 2.28 μg/kg. The mean levels of Aflatoxin B1 in the range of 4.17 to 71.18 μg -1 .kg -1 exceed the maximum residue limit (MRL) of 2 μg/kg for cereals and vegetables and 5 μg/kg for spices. The most contaminated samples of ochratoxin A (OTA) samples were dry cassava and adjovan with average concentrations of 0.94 μg/kg and 0.92 μg/kg. Low levels are 0.60 μg/kg and 0.48 μg/kg respectively for dry gumbo and dry maize. These mean OTA values of the samples analyzed are well below the maximum residue limit (MRL) of 5 μg/kg for vegetables, cereals and spices. This study presents the results concerning the safety assessment of a few foodstuffs regarding mycotoxins in Côte d'Ivoire.

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