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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-1) 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.

RESUMO A composição química e o estádio de maturação podem interferir no ponto de colheita do sapoti, a depender da destinação do fruto. Consequentemente, objetivou-se, com este trabalho, avaliar a influência da adubação potássica na qualidade e no potencial antioxidante do sapoti, em diferentes estádios de desenvolvimento. O experimento foi instalado na fazenda Norfruit, em Pau Branco, Mossoró, RN. O delineamento adotado foi em blocos casualizados, em esquema fatorial 5 x 6, composto por cinco doses de potássio (0, 200, 400, 600 e 800 g de K por planta) e seis estádios de desenvolvimento, com cinco repetições. Os frutos foram marcados ao atingirem 10 a 15 mm de comprimento; sendo colhidos e avaliados 90, 120, 150, 180 e 200 dias após sua marcação e completamente maduros (após oito dias de armazenamento a 25 ± 2 ºC e 58 ± 5% UR). O sapoti pode ser colhido 200 dias após a floração plena, quando atinge seu tamanho máximo e apresenta qualidade adequada para o consumo. O sapoti maduro tem maior teor de açúcares e menor concentração de compostos bioativos e atividade antioxidante. A dose de 400 g por planta de K proporciona frutos de maior massa, com maiores concentrações de polifenóis extraíveis totais e atividade antioxidante. A atividade antioxidante do sapoti está mais correlacionada com a concentração de polifenóis extraíveis totais.