Modified Atmospheric CO2 Levels for Maintenance of Fruit Weight and Nutritional Quality upon Long-Term Storage in Blueberry (Vaccinium corymbosum L.) ‘Liberty’

Abstract

Blueberry fruits have gained consumer attention in recent years due to their good taste and high nutritional value. However, the short shelf-life of the fruit is one of the main downsides in intensive blueberry production. Therefore, optimized storage technology with a modified atmosphere is necessary to prolong blueberry fruit quality on the market. The aim of this study was to investigate long-term storage of fruit of the highbush blueberry (Vaccinium corymbosum L.) ‘Liberty’ under the air control (0.5% CO2, 19.5% O2, 80% N2) and controlled atmosphere conditions of: 5% CO2, 5% O2, 90% N2; 15% CO2, 5% O2, 80% N2; and 25% CO2, 5% O2, 70% N2. Fruit sampling was performed four times during storage (17, 30, 44, 62 days). Evaluation was carried out for fruit weight, total and individual sugar and organic acid contents, sugar-to-organic acid ratio, and individual phenolics contents. After 44 days of storage, weight loss was highest with 15% CO2 and lowest with 5% CO2, with minor variations. The greatest breakdown of total sugars was seen for the air control, and the least for 25% CO2. Organic acids were significantly reduced under all of these storage conditions. Consequently, a high sugar-to-organic acid ratio was maintained in fruit stored with 25% CO2. The contents of all of the identified phenolics significantly decreased with 15% and 25% CO2. After 62 days of storage with 5% CO2, there were small decreases in flavan-3-ols and hydroxycinnamic acids, while flavonoid and anthocyanin contents were unchanged, or for some individual phenolics, content increased. These data show that 15% CO2 or higher accelerates degradation of the phenolics. We can conclude that for maintenance of weight and nutritional quality of the blueberry fruit ‘Liberty’, the optimal controlled atmosphere under long-term storage is 5% CO2, 5% O2, and 90% N2.