Problems and methods to improve the market-life of berry fruit

Berry fruit is highly perishable and it should be marketed soon after picking. When modern storage techniques are applied, fruit harvested in a particular season can be consumed some weeks later, decay is prevented and quality is ensured. In order to maximize storage life, fruit must have a high initial quality. The main factors, that limit the postharvest life of blueberries are excessive softening, water loss which results in fruit shrivelling, and the incidence of postharvest diseases (mainly caused by Botrytis cinerea and Colletotrichum gloeosporioides). Temperature management is the most critical postharvest factor, and for this reason, after harvesting, blueberries must be rapidly cooled and kept at temperatures close to 0°C for a maximum postharvest life. Cold storage, controlled atmosphere, modified atmosphere packaging, ozonation and innovative atmospheres have been used to extend the marketing season, reduce losses and increase profitability. However, the benefits of most of these treatments have been limited and often inconsistent. According to our experimental results, controlled atmosphere storage can maintain the quality and extend the storage life of blueberries. When added to refrigeration at close to 0°C, the controlled atmosphere maintained fruit firmness, the total soluble solids content and titratable acidity. Storage in plastic films reduced weight loss and slowed down the deterioration of the visual quality. In particular, berries packaged in micro-perforated (1mm ∅) and non-perforated films maintained their high quality attributes (high TSS content and titratble acidity)throughout the cold storage period. Non-perforated films maintained also berry crispness and a good intensity of flavour. Moreover, this treatment was the only one that reduced pathogen-induced decay during cold storage. The air treatment with ozone during the storage period was effective in reducing fungal decay, but little or no quality advantages were noted with the use of ozone on fruit firmness, soluble solids content or acidity.