Changes in quality and maturity of ‘Duke’ and ‘Brigitta’ blueberries during fruit development: postharvest implications

Fresh Chilean blueberries take in average 20-50 days to reach overseas markets, so a better knowledge of their postharvest behavior would help maintaining their quality for longer periods. Quality of highbush blueberries (Vaccinium corymbosum L. ‘Duke’ and ‘Brigitta’) was assessed at six stages based on color: 100% green (100G), 75% green + 25% pink (25P), 50% green + 50% pink (50P), 25% green + 75% pinkblue (75B), 90-100% blue (100B), 100% blue+5 extra days on plant (100B+5). Also, 75P, 100B and 100B+5 fruit were evaluated after storage at 2°C for 45 days + 1 d at 18°C. Over berry maturation from 100G to 100B, color developed steadily while firmness and TA decreased. Respiration and ethylene production rates peaked early, at 25P and 50P, respectively, and were higher for ‘Duke’ than for ‘Brigitta’. After harvest, cultivar- and maturity-related differences were found. ‘Brigitta’ fruit retained higher firmness and had lower weight loss than ‘Duke’. In general, 100B+5 fruit were over-ripe and showed low quality. Additional physiological, morphological and biochemical studies for a wider range of cultivars will be needed. This work was supported by the National Commission for Scientific and Technological Research (CONICYT) of Chile (grants FONDECYT 11130539 and PCHA/Doctorado Nacional/2013-63130042), and by the research program “Adaptation of Agriculture to Climate Change (A2C2)”, from Universidad de Talca, Chile. The work in Spain was supported partially by “Fundación Carolina” and “Programa de Doctorado en Ciencia y Tecnologı́a Agraria y Alimentaria”, from Universitat de Lleida, Spain.