A Novel Approach to Enhance Blueberry Quality During Storage Using Cold Plasma at Atmospheric Air Pressure

Abstract

Blueberry is an important health food, as it contains vitamins, anthocyanins, and antioxidative enzymes. However, post-harvest life of this fruit is very short, and its quality (in terms of microbial growth, antioxidant value, and decay rate) deteriorates rapidly during storage. In this work, air cold plasma at atmospheric pressure was evaluated as a pre-treatment approach for prolonging the shelf life and improving the quality of blueberries. After plasma treatment for 10 min, the number of bacteria and fungi decreased by 93.0% and 25.8%, respectively, which might be due to the increases in DNA damage and guanine oxidation. Accordingly, the blueberry decay rates reduced by 17.7%, 14.3%, and 5.2% in the plasma treatment groups of 6, 8, and 10 min, respectively, after 20 days of storage. Interestingly, the contents of sugar, vitamin C, and total anthocyanin as well as the superoxide dismutase activity level showed the maximum increases of 1.5-fold, 1.5-fold, 2.2-fold, and 79.3%, respectively, following different plasma discharge treatments and storage times compared with those in the control groups. Furthermore, in the treated samples, the degradation times for these four parameters to decrease to control levels were longer compared to the samples without treatment. These results indicated that air cold plasma at atmospheric pressure has excellent potential as a method for enhancing the quality and shelf life of fresh produce in the food industry.