Modified Atmospheric CO₂ Levels for Maintenance of Fruit Weight and Nutritional Quality upon Long-Term Storage in Blueberry (<i>Vaccinium corymbosum</i> 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.

Keywords

• highbush blueberry
• controlled atmosphere
• weight loss
• sugar-to-organic acid ratio
• phenolics