Polyphenol compounds and other quality traits in blueberry cultivars

BACKGROUND: Blueberry fruit available in the market comes from cultivars that have been selected for specific traits and not necessarily for high concentrations of health-promoting phytochemicals in the fruit. OBJECTIVE: To identify and quantify the total and individual phenolic components and other quality traits from a combination of cultivars from two Vaccinium species (V. corymbosum and V. virgatum). The cultivar combination provided a continuous and extended fruit harvest. METHODS: Fruit samples were collected from cultivars growing in a randomized complete block design. The phenolic components were assessed on fruit extracts, the fruit weight and firmness were assessed on fresh fruit and the rest of the traits were assessed on fruit juice. RESULTS: For most traits the differences between Vaccinium species and cultivars were considerable. Strong and positive correlations were found between phenolic components and between fruit traits. For each cultivar the majority of the traits analysed in this work from a single year were highly correlated to the average across the three years of evaluation. Assessing traits from a single year of data should be mostly reliable for individual cultivars. CONCLUSIONS: The combination of cultivars in this study was designed to offer the widest possible harvest window; however, it gives high variation in fruit quality.