Rice is the staple cereal in Senegal. Despite the many policies implemented over the last decade, Senegalese consumers still prefer imported over local rice. To understand this preference, this study compares consumer acceptability of three local rice samples versus two imported rice samples. Two focus groups and a consumer test with 120 women were carried out in the city of Saint‐Louis in Senegal. The results concerning consumption habits showed that about 85% of the surveyed women consume rice at least once a day (at lunch). The hedonic test showed that consumers appreciated all five rice samples, but the most liked samples were obtained from industrial processing of either local or imported whole and fragrant rice. The least liked sample was a local semi‐industrial rice, including 50% broken grains. The results of the just‐about‐right (JAR) test and check‐all‐that‐apply (CATA) test showed that the sensory descriptors such as white color, well‐cooked, and homogeneous grain size had an influence on the consumers’ choice of rice samples. However, the most important selection criteria were the homogeneous size of the rice grains, the absence of impurities, both of which are directly linked to the milling conditions, and fragrance, which is related to the variety. The origin of the rice samples did not influence the consumers’ choice. This study showed that local rice can compete with imported rice if processing is improved in some small‐scale rice mills.

Betacyanin stability was assessed over temperatures ranging from 60 to 90 °C for cactus pear (Opuntia dillenii Haw.) juice. The juice showed a betacyanin content of 0.76 g/kg. The rate constants for the betacyanin degradation and isothermal kinetic parameters were calculated according to the following three models: Arrhenius, Eyring, and Ball. The fittings of the models were found to be close to one other with SSE values of 0.0964, 0.0964, and 0.0974, respectively. However, because the estimated parameters for the Ball equation happened to be less correlated than the parameters of the other models, this equation was then used for the simulations. The parameters for z and D0 were 42.21 °C and 6.79 × 104 s, respectively. Betacyanins were found to resist typical heat treatment conditions (F70°C values between 100 and 200 min), with a maximum loss of 10% when the temperature was above 80 °C. The time/temperature combinations that could assure both the safety of the product and the preservation of the betacyanins were identified. With Enterococcus faecalis as the reference, when the temperature was 100 °C, the pasteurization time satisfying these two conditions was 0.6 min, whereas it was 180 min when the temperature was 62 °C. The degradation of betacynins during storage was positively correlated with temperature and was accompanied by the appearance of a brown shade.

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Slices (1.5 mm thick) of green papaya were impregnated through osmotic dehydration with a blackberry juice-sucrose solution to produce an intermediate moisture product. The effect of processing temperature (T) and sucrose-added molality (m sucrose ) on mass transfer during the operation was assessed, using a response surface methodology (RSM). The RSM was used to model water loss, sugar and anthocyanin gain during the process. Increasing sucrose molality resulted in increasing water loss and sugar gain, but decreasing anthocyanin gain. Water transfer therefore limits anthocyanin impregnation, but not sucrose incorporation. Afterwards, the impact of heat treatment at high temperatures was analysed, using numerical simulation. The conditions of the combined process, designed to achieve an anthocyanin-rich final product, are low sucrose-added molalities (sucrose molality < 1 mol kg -1 ) and high processing temperatures (T > 50°C) for osmotic dehydration, coupled with high-temperature, short-time (HTST) heat treatments for product stabilisation.

Mangifera indica species presents a wide varietal diversity in terms of fruit size and morphology and also of physicochemical and organoleptic properties of the pulp. In Senegal, in addition to the well-known export varieties, such as ‘Kent’, local varieties have been little studied particularly during ripening. This study aims to propose prediction models integrating variables deduced from varietal characteristics. Five mango varieties (‘Diourou’, ‘Papaye’, ‘Sierraleone’, ‘Boukodiekhal’ and ‘Sewe’) endemic to Senegal were characterized at harvest and followed during ripening storage. Caliber parameters were determined at green-mature stage as well as storage (25 °C) weight losses. Considering the ‘ripening storage time’ (RST) variable as ripeness level index, intra-varietal prediction models were built by multi-linear regression (R2 = 0.98) using pulp pH, soluble solid content (SSC) and Hue angle. In addition to these physicochemical parameters, variety-specific size, shape and weight loss parameters, were additional variables in multi-linear models (R2 = 0.97) for multi-varietal prediction of RST. Results showed that storage time, which was the most influential factor on the pH, SSC and Hue, can be used as a response for varietal prediction of mango ripening. As a decision support tool, theses statistical models, validated on two seasons, will contribute to reduce post-harvest losses and enhance mango value chain through a better ripening process monitoring.

Hibiscus sabdariffa L. (Malvaceae) calyx is a valuable food resource in Africa. This herb is rich in phenolic compounds and a good source of natural antioxidants. Concentrated extract prepared with Hibiscus sabdariffa L. calyx is commonly used in traditional African and Asian diets and medicines. However, the organoleptic properties of these extracts are degraded during storage. Therefore, the stability of these products is one of the problems faced by roselle calyx extracts users. Stabilization of the H. sabdariffa extract to prevent or reduce quality changes and to extend shelf-life of these products is a challenge to food processors. In this study, strategies for minimizing or eliminating these alterations were evaluated. Concentrated extract of hibiscus calyx (60 °Brix) was divided into three parts: control, pasteurized and addition of potassium sorbate. The samples were stored at 4, 30 or 45°C for three months. Reducing sugars, pH, titratable acidity and total anthocyanins were determined during 0, 15, 30, 45, 60, 75 and 90 days of storage. The results showed that hibiscus calyx extracts can be stored at 4°C for three months without any changes in organoleptic properties. Pasteurization and addition of potassium sorbate did not improve significantly, the stability of the concentrated extracts during storage periods at high temperature. However, these treatments extended the shelf-life at cooling temperature (4°C) without serious changes.

The Adansonia digitata L. known as Baobab is the only species present in West Africa and grows wild. All parts of the plant are used by humans. In Senegal, baobab pulp is widely consumed; it is used as raw material in small and medium enterprises (SMEs) for making juices, concentrates, jams, powder. Drinks or juices from baobab are highly appreciated by consumers; however rapid fermentation can happen even after pasteurization that can shorten their shelf-life. A Doehlert experimental design was used to find a good scale of heat treatment ensuring a proper conservation of baobab juice. Results of the experimental design showed that a heat treatment of 80˚C for 10 min gives a baobab juice with good sanitary quality that meets the international standards.

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