Mixed packaging-induced fresh-cut carrot and broccoli flavor change is associated with respiratory and energy metabolism

Fresh-cut carrot and broccoli are often packaged as mixes in the market, but their impact on flavor quality is unclear. Herein, we measured the flavor changes in mixed packaging of fresh-cut carrot and broccoli during storage at 15 ℃. Results showed that mixed packaging accelerated the loss of characteristic flavor compounds, while inhibited the accumulation of off-flavor substances of fresh-cut carrot and broccoli. The respiration rate, fructose-6-phosphate (6-P-F) and pyruvic acid contents, pyruvate kinase (PK) and phosphofructokinase (PFK) gene expression and activities of fresh-cut broccoli were elevated after mixed packaging. For fresh-cut carrot, mixed packaging also increased the respiration rate, pyruvic acid content and the expression of PK, while reduced 6-P-F content, PK and PFK activities, and PFK gene expression. Furthermore, mixed packaging improved energy level, cytochrome C oxidase activity, and up-regulated the gene expression of most ATP synthase of both fresh-cut carrot and broccoli. We therefore propose that the flavor changes in mixed packageing of fresh-cut carrot and broccoli might be related to respiration and energy metabolism.