Changes in quality characteristics of fresh blueberries: Combined effect of cultivar and storage conditions

The influences of two storage conditions (regular atmosphere-RA and modified-atmosphere packaging-MAP) and different storage time on fruit textural parameters, chemical composition, and total quality index (TQI) of two blueberry cultivars were investigated. Freshly harvested fruit of mid and late season cultivars (‘Bluecrop’ and ‘Liberty’, respectively) were placed in plastic punnets, packed into low-density polyethylene bags of 25 µm thickness with two perforations of 3 mm and stored at 2 °C and 90% relative humidity for 30 days, either in RA or in MAP. Changes in gas composition inside the package and fruit quality characteristics were analyzed at 10-day intervals during storage: 0, 10, 20, and 30 days. ‘Liberty’ was dominant over ‘Bluecrop’ in terms of hardness (428 g and 296 g, respectively), as well as individual and total sugars (100 and 76 g·kg–1, respectively), organic acids (19 and 12 g·kg–1, respectively) and most subclasses of phenolic compounds (anthocyanins, flavonols, and hydroxycinnamic acids). In addition, a novel mathematical index of TQI was introduced to compare all evaluated parameters in order to obtain a quantitative single score, as an indicator of overall fruit quality. ‘Liberty’ had the better TQI score in RA, whereas ‘Bluecrop’ behaved better in MAP. Accordingly, for longer storage of blueberry fruit MAP should not be assumed to be uniformly helpful, since the effect of storage duration in the specific type of atmosphere substantially depends on the proper cultivar selection.