Effect of Ultrasound Treatment Combined with Carbon Dots Coating on the Microbial and Physicochemical Quality of Fresh-Cut Cucumber

Abstract

Effect of ultrasound (US) treatment combined with carbon dots (CDs) coating on the microbial and physicochemical quality of fresh-cut cucumber was investigated. Cucumbers were dealt with ultrasound (226 W/cm2), CDs coating with CDs concentration of 4.5%, and their combination and then packaged and stored for 15 days at 4 °C. Results exhibited that US treatment combined with CDs coating markedly inhibited total bacterial count to 5.18 log CFU g−1, mold and yeast to 3.45 log CFU g−1 after 15 days of storage. US treatment combined with CDs coating also kept minimum respiration rate of 4.67 mg kg−1 h−1 CO2, weight loss of 8.54%, and malondialdehyde content of 2.24 μmol kg−1 and higher total soluble solids of 2.29 °Brix, firmness of 6.78 N, and ascorbic acid content of 0.0243 g kg−1; inhibited peroxidases activity to 139.83 U kg−1 s−1 and polyphenol oxidase activity to 137.17 U kg−1 s−1; preserved flavor and taste; and reduced the change of water status after 15 days of storage. These results illustrated that US treatment combined with CDs coating can effectively improve the microbial and physicochemical quality of fresh-cut cucumber.