CHEMICAL AND PHYSICO-CHEMICAL CHARACTERIZATION, AND ANTIOXIDANT ACTIVITY OF ITALIAN TOMATOES (LYCOPERSICON ESCULENTUM MILL.) UNDER ORGANIC CROP MANAGEMENT

Abstract

The purpose of this study was to evaluate the chemical and physico-chemical characteristics as well as to measure the antioxidant activity of two Italian tomato hybrids (‘San Vito’ and ‘HEM 031’), growing under organic production in Brazil. The hybrid cultivars are from Brazil and can be used fresh or processed. The amounts of organic compost applied were: 6, 12, 24, 40 t/ha, equivalent to 100, 200, 400, 800 kg/ha of N. The following was evaluated: the total soluble solids, total titratable acidity, pH, ascorbic acid, β-carotene and lycopene, mineral content (Na, Mg, P, K, Ca, Mn, Fe, Cu, Zn, Al) and antioxidant activity by TRAP, FRAP and TEAC assays. Results were analyzed by ANOVA and LSD tests, at 5% significant levels. Differences between both hybrids were observed only for total soluble solids, ascorbic acid and pH, with higher values for ‘San Vito’. The amount of organic fertilizer applied affected the hybrids’ total titratable activity. The lycopene and β-carotene contents were influenced by the interaction hybrid×fertilization levels. The lowest level of fertilization (100 kg/ha N equivalent) produced higher levels of lycopene and β-carotene only in ‘HEM 031’ hybrid, with no differences in ‘San Vito’. For mineral content, only K, Fe, Ca and P showed statistical differences. The Ca concentration increased with the level of fertilization. Increases in P concentration were observed in ‘HEM 031’ hybrid fertilized with 200 and 800 kg/ha of N, while in ‘San Vito’ hybrid, only the lowest level of fertilization decreased P concentration, comparing to the other fertilization levels. The specific hybrid, the level of fertilization and the assay applied, affected the antioxidant activity results. The hybrid ‘HEM 031’ showed higher values of K and Fe compared to ‘San Vito’.