Colored onion bulb is an important source of antioxidants. Some ecological factors can significantly influence the content and quality of these substances. The aim of the present study is to determine the antioxidant and total polyphenol content of fresh bulbs of five (05) varieties of onion (Galmi Violet, Damani Violet, Prema, Safari and a Local variety-LV) grown in Burkina Faso, and to evaluate also the influence of agro-ecological parameters on the antioxidant content of the most cultivated variety (Galmi violet) of them. Samples of onion bulb for analysis were collected in the six agro-ecological areas of Burkina Faso under the same cultivation conditions. Antioxidant activities were evaluated using the method of Ferric Reducing Antioxidant Power. The evaluation of the total polyphenol contents was carried out using the Folin-Ciocalteu method. The results showed that antioxidant activities for the 5 varieties tested vary between 0.125 ± 0.001 and 0.149 ± 0.004 mg TE / g, and total polyphenol contents from 0.172 ± 0.011 to 0.272 ± 0.003 mg EAG/g. Results on the assessment of the effect of ecology on the antioxidant content of Galmi violet variety revealed significant variations in antioxidant content from 0.144 ± 0.002 to 0.155 ± 0.001 mg TE / g, and total polyphenols from 0.208 ± 0.014 to 0.292 ± 0.012 mg EAG / g depending on the ecological cultivation area.

Background Microbial contamination of edible low moisture food poses a significant public health risk for human. In this study, the microbial quality of sweet dehulled sesame seed croquettes, salted dehulled sesame seed and the raw sesame seed, sold under ambient conditions were examined. The samples were collected in the cities of Burkina Faso. The first type is sweet dehulled sesame seed croquettes (n1 = 25); the second type is salted dehulled sesame seed (n2 = 25) and the third type is raw sesame seed (n3 = 25). Assessment of the microbial quality was based on the total aerobic mesophilic bacteria, the thermotolerant coliforms, the yeasts and moulds, the E. coli, and the Salmonella spp. using ISO methods. Results The results showed the presence of microorganisms varying from <1.0 to 1.72 × 105 CFU g− 1 for thermotolerant coliforms, from <1.0 to 6,12 × 106 CFU g− 1 for the total mesophilic aerobic flora and from <1.0 to 8.10 × 105 CFU g− 1 for yeasts and moulds. The higher contaminations rates were mostly observed in raw sesame seed samples. No E coli or Salmonella pathogens were detected. Based on international standards of dehydrated food, 50.67% of the ready to eat sesame are satisficing while 17.33% are acceptable and 32% are not satisficing. Conclusion Attention should be emphasized on the processing practices, especially in crowded places where RTE sesames seeds are mostly sold. The high numbers of all microbial groups in these sesame seed samples suggested that the production of RTE sesame seed should be improved by better hygiene. This study highlights also that RTE sesame seed might harbor a wide range of microorganisms when processes are weak of hygiene.

Nowadays, organic foods are recognized for having a better nutritional quality than those from conventional agriculture, which explains the growing demand for organic vegetables. For the present research, three tomato cultivars, Mongal F1, Roma VF and F1 Cobra 26 were grown using conventional and organic methods, to assess the impact of cultivation practices and drying method on the micronutrient content of these cultivars. Samples were compared for micronutrient content of lycopene, β-carotene, flavonoids, vitamin C and total content of phenolic compounds using the FRAP and DPPH methods. The results show a high antioxidant activity (5901.338 mmol TE/100g and 6020.545 mmol TE/100g) and a high content of total polyphenols (1595.046 mg EAG/100g DM) for organic growing. The average contents of flavonoids (121.572 mg/100g DM and 129.053 mg/100g DM), β-carotene (39.618 mg/100g DM and 39.751 mg/100g DM), lycopene (169.739 mg/100g DM and 168.894 mg/100g DM) and vitamin C (301.995 mg/100g and 268.252 mg/100g DM) in tomatoes from organic and conventional cultivation show no statistically significant difference. After drying, results report an increase of 188.88% of Flavonoids content (from 62.413 ± 47.285 for mashed tomato to 180.304 ± 72.152 for dried Tomato); a decrease of 34.60%, 27.18% and 47.95% respectively for β-carotene content (from 47.388 ± 1.615 mg /100g DM for mashed tomato to 30.988 ± 0.767 mg /100g DM for dried tomato), lycopene content (from 188.085 ± 7.100 mg/100g DM for mashed tomato to 136.955 ± 2.810mg/100g DM for tomato dried) and vitamin C content (from 385.686 ± 37.825 mg/100g for mashed tomato to 200.743 ± 14.181mg/100g DM for dried tomato). There is variability in the micronutrient content depending on the variety of tomato, the cultivation practice and the processing technique used. Organic cultivation practice improves the micronutrient content. Using gas dryers for drying has the most detrimental effects on the micronutrient content.

Red onion bulb is a vegetable containing micronutrients with antioxidant properties. However, certain factors can have an impact on the content of these compounds. The present research evaluate the effects of parameters such as cultural practices, storage conditions and culinary practices, on the antioxidants content of red onion bulb of some varieties grown in Burkina Faso. The identification of the factors was carried out through field surveys, and their effects on the antioxidants content were assessed and appreciated through especially specific related bibliographic and laboratory test data. The results showed that84.78% of farmers use chemical fertilizers and all of them use chemical pesticides on onion crop. They don't use premises or equipment suitable for storage. About dishes,7.61% of cooks, peel, cut and wash onion bulb before steam cooking, boiling water cooking or oil frying them at high temperature during 30 minutes to 3 hours. Some cooks use to braise onion bulb scales as ingredients for different dishes such as barbecue. Only 02,72% of cooks grind the onion bulbs with a pestle, before using the crushed as such on barbecue, or slow cooking it in different sauces. Research results show that these culinary practices contribute declining significantly the final intake of antioxidant for the consumer's body.