|DE FREITAS, SERGIO
Submitted to: Revista Brasileira de Fruticultura
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/24/2022
Publication Date: 4/29/2022
Citation: Vieira, M., Argenta, C., Brancher, T.L., de Freitas, S.T., Mattheis, J.P. 2022. Relationship among dry matter content and maturity indexes at harvest and quality of 'Gala' apples after storage. Revista Brasileira de Fruticultura. 44(2). Article e-841. https://doi.org/10.1590/0100-29452022841.
Interpretive Summary: Apple fruit can be stored for months after harvest due to the availability of technologies that slow fruit ripening. However, variation exists among orchard lots at the time of fruit harvest that impacts how well any individual group of fruit will hold its quality during an extended storage period. Predicting how well any orchard lot will store currently is an imperfect process that would benefit from additional easy to perform measures that can be done at the time of harvest. This study evaluated fruit dry matter content at harvest as a predictor for storage performance. The results showed for ‘Gala’, a cultivar that is at high risk of losing firmness during storage, that dry matter content at harvest is not a good predictor of firmness loss during storage. Dry matter content at harvest did show a relationship to fruit sugar content and tartness after storage. This finding has potential utility to industry as sugar content and tartness are important quality attributes for apple fruit.
Technical Abstract: The objective of this study was to determine the relationship among dry matter content (DMC) and maturity indexes at harvest and quality of ‘Gala’ apples after storage. Apple fruit of four 'Gala' strains produced on two rootstocks and three growing regions were used for the experiments 1 and 2. For experiment 1, the fruit were harvested weekly along the final stages of growth and maturation on the tree and were analyzed one day after harvest. Experiment 2, the fruit were harvested once at the commercial maturity and stored under controlled atmosphere at 0.7 oC for 195 days. Experiment 3, the fruit from two orchards were harvested once at the commercial maturity and stored in air at 1oC for 50, 110 or 194 days. Fruit from experiments 2 and 3 were assessed one day after harvest and after storage plus seven days at 22 °C. DMC did not change during the final stages of fruit growth, when there were significant changes in fruit firmness, starch index, and soluble solids content. At the commercial harvest, fruit DMC showed high correlation with soluble solids content (SSC), titratable acidity (TA), and firmness. DMC assessed at the commercial harvest also showed high correlation with SSC and TA after storage, but not with firmness or flesh browning (FB) after storage. DMC showed a slight decrease during storage. The results show that DMC is not a reliable index to determine 'Gala' apple maturity at harvest, as well as to predict fruit firmness and FB after storage. However, DMC at harvest might be a useful index to predict SS and TA after storage, which are important quality traits.