Physicochemical Characteristics, Antioxidant Capacity and Phenolic Compounds of Tomatoes Fertigated With Different Nitrogen Rates

Abstract

-The objective of this work was to evaluate the physicochemical and microbiological characteristics, antioxidant capacity and phenolic compounds of organic cherry tomatoes grown under fertigation with organic dairy cattle wastewater (DCW) with different nitrogen rates. Tomato plants, grown in an agroecological farm in Seropédica, State of Rio de Janeiro, Brazil, were subjected to four different nitrogen rates (T1=0, T2=50, T3=100 and T4=150% of N). The moisture, lipids, ashes, protein and total fiber contents, soluble solids (ºBrix), reducing and total sugars (%), pH and total titratable acidity (mg NaOH per 100 g) were evaluated. The total phenolic content (TPC) and the antioxidant capacity was determined by the DPPH and FRAP methods. The different nitrogen rates (%N) affected the pH, protein and soluble solids contents. The increase in %N increased the antioxidant capacities, according to the DPPH assay, and TPC. On the other hand, the tomatoes under fertigation with the highest %N presented lower antioxidant capacities according to the FRAP assay. The fertigation did not affect the microbiological characteristics of the tomatoes, which presented fecal coliforms count <3 NMP g -1 and absence of Salmonella in 25 g. Keywords:Fertirrigation. Physicochemical composition. Solanum lycopersicum L.. CARACTERÍSTICAS FÍSICO-QUÍMICAS, CAPACIDADE ANTIOXIDANTE E COMPOSTOS FENÓLICOS TOTAIS DE TOMATES FERTIRRIGADOS COM DIFERENTES DOSES DE NITROGÊNIORESUMO -O objetivo deste trabalho foi avaliar a capacidade antioxidante e a qualidade fisicoquímica e microbiológica de tomates cereja orgânicos cultivados com diferentes teores de nitrogênio (%N) utilizando águas residuárias da bovinocultura. As amostras de tomate foram obtidas na Fazendinha Agroecológica (SIPASeropédica, RJ) e submetidas a quatro diferentes tratamentos de acordo com os níveis de nitrogênio (T1=0, T2=50, T3=100 e T4=150 %N). Foram determinadas a umidade, teores de cinzas, lipídeos, proteínas e fibras totais. Além do pH, sólidos solúveis (ºBrix), açúcares totais e redutores (%); e acidez titulável (mg de NaOH por 100 g

<b>Organic cherry tomato yield and quality as affect by intercropping green manure

“…However, there was a difference (p < 0.1) between the years for all variables, except for the soluble solids content (Figure 3). The average values of the chemical characteristics of this study on cherry tomato SST 6.5 Brix, pH 4.35, were similar to the values found by Jorge, Nascimento, Junior, Silva, and Barbosa (2017) (Figure 3). …”

Antioxidant content of Tomatoes (Lycopersicon esculentum cv MT1) treated by different type of Pesticide, Fertilizer and growth medium in Compost

“…This result may due to no fertilizer apply which can cause stress to plant. Thus, the plant will produce high antioxidant biomolecule 23 . Antioxidant levels can be increased and activated by plant defense systems against pests and diseases or other stress factors 24 .…”

Análise físico-química e microbiológica de tomates cereja (Solanum lycopersicum var. cesariforme) comercializados em empórios de Manaus-AM

“…Nas condições avaliadas, a média do conteúdo de umidade das amostras foi de 94,74%, resultado similar aos reportados por Vieira et al (2014) que avaliaram a composição centesimal de tomates cereja obtidos em Goiás. Loro (2015) e Jorge et al (2017) relataram umidade de 92,03% e 91,48% em variedades de tomates cereja variedade Sweet grape e em amostras orgânicas obtidas em São Paulo e no Rio de Janeiro, respectivamente. Os tomates avaliados possuem conteúdo superior a 40%, podendo ser classificados como alimentos de alta umidade de acordo com as citações de Melo Filho e Vasconcelos (2016).…”