Moisture sorption isotherms play an essential role in preservation and storage of dehydrated food. To study the behavior of sucrose, it’s moisture adsorption isotherm was investigated using the static gravimetrique method at laboratory temperature (29 ±1°C) in a water activity range (aw) of 0.07-0.97. The results showed that the equilibrium moisture content of sucrose increase substantially above aw = 0.6. The moisture adsorption isotherm was sigmoid in shap, showing a type III BET isotherm. The data obtained were fitted to several models including two-parameter (BET, Hasley, Kuhn and Oswin), three parameter (GAB). A non-linear least square regression analysis was used to evaluate the models constants. The GAB model best fitted the experimental data in the wide range of water activity. The best fitted equation provide a sound basis for futur work on the drying and storage of sucrose. The accurate moisture content and the stability profile of sucrose were determined. The results of determination show that sucrose powder was stable below 7.7% RH at 29°C. The content of water adsorbed in the monomolecular layer was calculated (GAB Xm=0.950 g H2O/100 g solids; BET Xm= 1.072 g H2O/100 g solids).

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.

Inadequate handling, processing and sales of meat products have resulted in microbial contamination responsible for most infectious human food-borne illness. The study conducted a stochastic assessment of the risk of infection linked to the consumption of braised beef meat "Choukouya" contaminated by Clostridium perfringens in Côte d'Ivoire. We conducted "Choukouya" consumers (n = 900) and vendors (n = 300) survey to characterize the actors behavior. 189 samples of "Choukouya" were collected and microbiologically analyzed according to French standard protocols NF V 08-061 and XPV 08-061. A risk model was developed and the risk of infection linked to the consumption of "Choukouya" was estimated by Monte Carlo simulation procedure. The consumer's surveys showed that the percentage of population consuming "Choukouya" was 74.4%, with an average consumption of 114.3 ± 0.5 g/person/intake. The microbiological analysis revealed the isolation of 70% of Clostridium perfringens in the vegetative form and 60.3% in sporulated form with an average loading of 3.7 ± 2.6 log 10 •cfu/g and 1.1 ± 1.0 log 10 •cfu/g respectively. The probability of ingesting a dose greater than 10 9 bacteria of Clostridium prefringens varied between 7.36% and 7.93%. The braised beef meat "Choukouya" sold in the streets of cities in Côte d'Ivoire represents a real risk of infection, and Clostridium perfringens is one of the causes. This risk could be mitigated by the establishment of good hygiene practices and adequate handling processes in this informal sector.

No abstract

The 3C Ivoire EuropeAid project (2011–2015), set up a coordination committee in Ivory Coast to evaluate the effectiveness of sanitary controls, prevent sanitary risks and coordinate nationwide actions on food safety [1]. This paper reports main findings: difficulties to apply regulations in Ivory Coast, to establish a national food safety agency, to implement a national health surveillance system, to set up a potential food safety label, training on food safety systems (HACCP, traceability, good hygiene practices), first experimental committee of national experts. Ivoirians are concerned by food safety hazards. All food samples collected in markets were contaminated by pathogens. Three of the main food consumed in the country: rice, maize, peanut were contaminated with mycotoxins, and aflatoxin levels in peanut paste were well above the EU limits. The decree creating the Ivorian agency was signed in late June 2016. (Résumé d'auteur