Camu-camu harvested with reddish-green peel preserves its physicochemical characteristics and antioxidant compounds during cold storage

Abstract Camu-camu (Myrciaria dubia), a fruit native to the Brazilian Amazon, is considered a source of antioxidant compounds. Due to its high perishability, postharvest studies aimed at increasing its shelf life are required. The aim of this study was to evaluate the influence of harvesting time on the conservation of the physicochemical characteristics and antioxidant compounds of camu-camu during cold storage. The fruits, harvested at different ripening stages (red and reddish-green peel), were stored in polyethylene terephthalate trays at 15 °C and 90% relative humidity. The following analyses were carried out on days 1, 2, 5, 7, 9 and 13 after harvest: luminosity, hue angle and chromaticity, pH, soluble solids content, titratable acidity, SS/TA, ascorbic acid content, total phenolic content, total anthocyanin content and free-radical-scavenging activity by the 1,1-diphenyl-2-picryl-hydrazil method. The data were submitted to a multivariate analysis. The fruits harvested at different ripening stages showed different postharvest characteristics, highlighting the parameters of colour, flavour and antioxidants. The reddish-green fruits, despite their low concentration of anthocyanins during storage, showed high levels of phenolic compounds, ascorbic acid and antioxidant activity, which were maintained for nine days of cold storage. Due to the flavour characteristics and antioxidant compounds, it is recommended that camu-camu be harvested in the reddish-green maturation stage to extend its shelf life. Resumo Camu-camu (Myrciaria dubia), uma fruta nativa da Amazônia brasileira, é considerada uma fonte de compostos antioxidantes. Devido à sua elevada perecibilidade, são necessários estudos em pós-colheita para aumentar a sua vida útil. O objetivo deste estudo foi avaliar o ponto de colheita do camu-camu na conservação de suas características físico-químicas e compostos antioxidantes durante o armazenamento a frio. Os frutos foram colhidos em diferentes estádios de maturação (casca vermelha e verde-avermelhada). Os frutos foram armazenados em bandejas de politereftalato de etileno a 15 °C e 90% de umidade relativa. As análises foram realizadas nos dias 1, 2, 5, 7, 9 e 13, após a colheita: luminosidade, °hue e cromaticidade, pH, conteúdo de sólidos solúveis, acidez titulável, conteúdo de ácido ascórbico, conteúdo fenólico total, conteúdo total de antocianina e atividade antioxidante. Os dados foram submetidos à análise multivariada. Os frutos colhidos em difer