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Abstract

This study aimed to evaluate the effect of nitrogen fertilization on the physical and physico-chemical characteristics and antioxidant potential of sapodilla at different stages of development. The experiment was installed at the Norfruit farm, located in the rural community of Pau Branco, Mossoró/RN, Brazil. A randomized block with two factorial schemes experimental design, was adopted. The first 5 x 6 with lost parcels, consisting of five doses of nitrogen (N) (0, 300, 600, 900 and 1200 g of N.plant ) and six stages of fruit development; and the second 2 x 3 consisting of two levels of nitrogen (N) (0; 600 g of N plant -1) and three stages of development, both with five replications. The fruits were labeled with a 10 to 15 mm long mark in the plant. In fact, were harvested and analyzed after 90, 120, 150, 180 and 200 days of its marking and 208 days (fully mature, after 8 days of storage at 25 ± 2 °C and RH 58 ± 5%), respectively. The results showed a nitrogen fertilization at the dose of 600 g of N.plant -1 , produced fruit with higher sugar content and fresh weight, reaching greater mass and sugar content, at 200 and 180 days of fruit development, respectively. An increase in nitrogen fertilization, promoted a reduction in the levels of yellow flavonoids and anthocyanins. Bioactive compounds (total polyphenols, vitamin C, flavonoids and anthocyanins) and sapodilla antioxidant activity decreased with the further development of fruit. The antioxidant activity of the sapodilla is more related to the high content of total polyphenols. The knowledge obtained in this study is extremely important for the sapodilla production chain due to information of the nutritional and antioxidant composition of the fruits. This also proves beneficial for the fruit marketing, because nowadays the public seeks foods rich in antioxidants, and the sapodilla is marketed both in natura and processed, in addition to its use in the cosmetics manufacture.Key words: Bioactive compounds, chemical composition of fruits, mineral nutrition, ripening. ResumoEsse trabalho objetivou avaliar o efeito da adubação nitrogenada nos caracteres físico, físico-químico e potencial antioxidante do sapoti em diferentes estádios de desenvolvimento. O experimento foi instalado na fazenda Norfruit, localizada na comunidade rural de Pau Branco, município de Mossoró/RN. O delineamento adotado foi em blocos casualizados com dois esquemas fatoriais, o primeiro 5 x 6 com parcelas perdidas, composto por cinco doses de nitrogênio (N) (0; 300; 600; 900 e 1200 g de N planta -1 ) e seis estádios de desenvolvimento do fruto; e o segundo 2 x 3, composto por duas doses de nitrogênio (N) (0; 600 g de N planta -1 ) e três estádios de desenvolvimento, ambos com cinco repetições. Os frutos foram marcados com 10 a 15 mm de comprimento na planta; sendo colhidos e avaliados após 90, 120, 150, 180 e 200 dias de sua marcação e 208 dias (completamente maduros, após 8 dias de armazenamento a 25 ± 2 °C e UR 58 ± 5%). Os resultados obtidos permitiram concluir que a adubação n...