Impact of organic or conventional cultivation and drying method on phenolic compounds, carotenoids and vitamin C contents in tomato

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.