The aim of this study was to evaluate the effect of steam blanching processing on the nutritive value and the antioxidant properties of fi ve leafy vegetable species (Amaranthus hybridus, Andasonia digitata, Ceiba patendra, Hibiscus sabdariffa and Vigna unguiculata) that are used for sauce preparation in Northern Côte d'Ivoire. The selected leafy vegetables were subjected to blanching in pressure cooker for 15, 25 and 45 min and the physicochemical properties were determined using AOAC methods. The result of the study revealed that longer time of blanching (higher than 15 min) caused negative impact by reducing nutritive value but positive impact by reducing anti-nutrients and increasing polyphenols. The registered losses (p<0.05) at 15 min were as follow: ash (0.08-10.01%), proteins (0.36-12.03%), vitamin C (19.56-68.67%), carotenoids (18.91-55.48%) oxalates (3.58-21.39%) and phytates (10.51-68.02%). The average increase of polyphenols contents at 15 min of blanching was 1.61 to 30.72%. In addition, a slight increase (0.35-4.16%) of fi bres content was observed in the studied blanched leafy vegetables. Furthermore, after 15 min of blanching time the residual contents (p<0.05) of minerals were: calcium (264.88-844.92 mg/100 g), magnesium (49.45-435.43 mg/100 g), potassium (675-1895.41 mg/100 g), iron (14.54-70.89 mg/100 g) and zinc (9.48-36.46 mg/100 g). All these results suggest that the recommended time of domestic blanching must be less than 15 min for the studied leafy vegetables in order to contribute effi ciently to the nutritional requirement and to the food security of Ivorian population. Unauthenticated Download Date | 5/11/18 6:45 PM

Leafy vegetables are highly perishable and often subjected to post-harvest wastes. Among the various methods of preservation, the effect of shadow drying on the nutritive value and antioxidant properties of five (5) leafy vegetables species widely consumed in Northern Côte d'Ivoire was investigated. These species were Amaranthus hybridus, Andasonia digitata, Ceiba patendra, Hibiscus sabdariffa and Vigna unguiculata. Experiment was conducted as follow: portions of washed and drained fresh leafy vegetables (500 g) were spread on clean filter paper and kept in a well-ventilated room of the laboratory at 25°C for 5, 10 and 15 days. The results of proximate composition after 15 days of shadow drying were: moisture (15.19 -20.36%), ash (9.14 -19.54%), crude fiber (11.04 -27.40%), proteins (11.14 -17.94%), lipids (2.41 -5.86%) and carbohydrates (16.59 -45.14%). The concentration of minerals increased with respective values after 15 days of shadow drying: calcium (68.14-408.09 mg/100 g), magnesium (50.62-317.23 mg/100 g), iron (27.52-92.03 mg/100 g) and zinc (10.17-16.73 mg/100 g). During shadow drying, vitamin C and carotenoids were subjected to losses estimated to 35.52 -70.50% and 22.82 -45.63%, respectively. Contrary to these losses, antioxidant activity increased and ranged from 57.45 to 75.55 % after 15 days of shadow drying. All these results suggest that the considerable nutrient contents of shade dried leafy vegetables make them good source of food supplements in order to meet the nutritional requirements of Ivorian population.

Storage and processing technologies have been utilized for centuries to prevent post harvest losses of vegetables and to transform them into safe, delicious and stable products. The aim of this study was to evaluate the effect of refrigeration storage (4°C) on the nutritional value of five leafy vegetables (Hibiscus sabdariffa, Amaranthus hybridus, Andasonia digitata, Vigna unguiculata and Ceiba patendra) that are consumed in Northern Côte d'Ivoire. The selected samples were subjected to storage at 4 °C for 5, 10 and 15 days and the physicochemical properties were determined using standard methods. Fresh selected samples were used as the control. The result of the study revealed that increased storage time affected the nutritional value of the selected leafy vegetables. The registered losses at 15 days of refrigeration storage were as follow: ash (2.41-9.70%), proteins (5.66-18.97%), vitamin C (11.43-41.29%), carotenoids (25.44-41.29%), oxalates (12.43-14.55%), phytates (35.03-44.10%). It was observed an increase (0.17-2.41%) in total phenolic content during storage. In addition, a small increase (0.88-2.66%) of fibres content was also observed in the studied leafy vegetables stored under refrigeration at 4°C. Furthermore, after 15 days of storage at 4°C the residual contents of minerals were: calcium (308.30-858.75mg/100g). Magnesium (213.64-610.14 mg/100g), potassium (565.32-1844.08 mg/100g), iron (49.29-160.53 mg/100g) and zinc (17.95-34.06 mg/100g). The result of the present study suggests that vegetables should be stored in cold storage for a short time (less to five days) in order to avoid loss of essential nutrients.

Leafy vegetables play an important role as essential components of diet for rural populations in tropical Africa. This study was undertaken to provide a more comprehensive characterization of carotenoids and phenolics in these neglected plant foods. For this, 12 leafy vegetables widely consumed in Côte d'Ivoire were selected, washed and oven-dried (50°C/3 days) before High-Performance Liquid Chromatography (HPLC) analysis of carotenoids and phenolics compounds. Carotenoids contents were significantly different (p ˂ 0.05) with lutein (43.68 ± 4.89 -513.91 ± 5.68 μg/g dw) and all trans-β-carotene (22.62 ± 1.54 -222.61 ± 5.63 μg/g dw) as major constituents. The calculated retinol activity equivalent (RAE) of β-carotene-rich leafy vegetables in this study ranged between 1.54 and 2.52 mg/100 g. The values of total phenolics ranged from 179.66 ± 11.33 mg/100 g dw in Corchorus olitorius to 436.48 ± 1.73 mg/100g dw in Abelmoschus esculentus. Three (3) flavonoids: quercetin (0.79 -8.36 μg/g dw), catechin (0.39 -5.65 μg/g dw) and kaempferol (0.76 -29.11 μg/g dw) were quantified in the selected leafy vegetables. Chlorogenic