Impact of Shadow Drying on Nutritive and Antioxidant Properties of Leafy Vegetables Consumed in Southern Côte D’Ivoire

The abundance of leafy vegetables during the rainy seasons and poor transport and storage systems lead to their post-harvest losses in dry seasons. Effective preservation and storage of these plants would not only reduce their post-harvest losses but make them available throughout the year. Therefore a study was conducted on shadow drying effect on the nutritive and antioxidant properties of five selected leafy vegetables consumed in Southern Côte d’Ivoire. 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 the proximate composition after 15 days of drying were: moisture (14.16 – 20.51%), ash (8.30 -19.16%), crude fibres (11.43 – 21.27%), proteins (9.13 – 19.05%), lipids (3.29 – 7.97%) and carbohydrates (32.45 – 51.74%). The minerals concentration increased with respective values after 15 days of shadow drying: calcium (78.23-337.26 mg/100g), magnesium (70.41-208.46 mg/100g), phosphorus (50.73-184.81 mg/100 g), potassium (363.56-776.73 mg/100g), iron (12.14-63.57 mg/100g) and zinc (12.57-33.95 mg/100g). During shadow drying, vitamin C and carotenoids were subjected to losses estimated to 65.52 – 91.07% and 39.66 – 95.23%, respectively. Contrary to these losses, antioxidant activity increased and ranged from 66.10 to 74.33% 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 when supplemented with sources of vitamin C and carotenoids in order to meet the nutritional requirements of Ivorian population

Quality protein maize (QPM) seeds grown in Côte d’Ivoire: A source of high value edible oil

The search for new sources of oil with improved properties has focused our attention on the characteristics of oils extracted from white and yellow quality protein maize (QPM) seeds, two hybrids of classic maize (Zea mays L.). Physicochemical parameters of extracted oils were respectively as follow: refractive index (1.47 ± 0.00), free fatty acids (FFA) (1.4 ± 0.00 %), peroxide value (2.00 ± 0.00 and 1.33 ± 0.60 meq O2/kg), iodine value (136.20 ± 1.22 and 137.60 ± 1.22 g I2/100 g), and saponification value (203.83 ± 1.62 and 205.70 ± 1.62 mg KOH/g). Biochemical and nutritive analysis have revealed the following assets: unsaponifiable matter (1.43 ± 0.21 and 1.70 ± 0.10%), phosphorus (0.10 ± 0.02 mg/g), carotenoids (0.86 ± 0.01 and 1.06 ± 0.01 mg/g), vitamin A (0.45 ± 0.01 and 0.63 ± 0.01 mg/g) and vitamin E (0.32 ± 0.01 and 0.39 ± 0.01 mg/g). White and yellow QPM oilseeds showed higher content of linoleic acid (~ 60.2 % of total fatty acids). All these interesting characteristics should arouse attention for the usage of white and yellow QPM oilseeds as alternative to traditional corn oil in food and pharmaceutical industries.Keywords: Zea mays, quality protein maize, seed oils characterization, vitamin E, linoleic acid.African Journal of Biotechnology Vol. 12(23), pp. 3710-371

Evaluation of Nutritive and Antioxidant Properties of Blanched Leafy Vegetables Consumed in Northern Côte d’Ivoire

The aim of this study was to evaluate the effect of steam blanching processing on the nutritive value and the antioxidant properties of five 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 (p0.05) 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 fibres content was observed in the studied blanched leafy vegetables. Furthermore, after 15 min of blanching time the residual contents (p0.05) 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 efficiently to the nutritional requirement and to the food security of Ivorian populatio

Two Novel Non-Conventional Seed Oil Extracts with Antioxidant and Antimicrobial Activities

Purpose: To investigate the seed oils of Corchorus olitorius and Hibiscus sabdariffa for their antioxidant and antimicrobial potential. Methods: The physicochemical characteristics of oil of the plant seeds were determined using standard methods while their volatile compounds were analyzed by gas chromatography coupled with mass spectrometery (GC-MS). The antioxidant activity of these oils was determined using 2,2-Diphenyl-1- picrylhydrazyl (DPPH) free radical scavenging method, and their antimicrobial effect was determined by agar dilution method. Results: Phospholipids, carotenoids and phenols contents of the studied seed oils were approximately 2.0 %, 100 mg/100g and 6.7 mg/100g, respectively. GC-MS analysis of the volatile compounds showed the presence of various aromatic and aliphatic organic compounds while the antioxidant activity of the oils was in the range of 0 to 5 g/l, which was higher than that of ascorbic acid. The seed oils also showed antimicrobial activity against Staphylococcus aureus , Aspergillus fumigatus and Trichophyton mentagrophytes with minimal inhibitory concentrations (MIC) of 250.0 and 62.5 mg/ml for C. olitorius and H. sabdariffa seed oils, respectively. Conclusion: C. olitorius and H. sabdariffa seed oils showed pronounced antioxidant and antimicrobial activities. These characteristics should be exploited for possible applications in the food supplement, pharmaceutical and cosmetic industries