Investigating the relationship between volatile components and differentially expressed proteins in broccoli heads during storage in high CO2 atmospheres

Abstract Broccoli heads usually age by yellowing or producing an off-flavor after harvesting and during storage under improper conditions. However, the reasons for the off-flavor are complex, and the factors affecting the development of this characteristic is unclear. This study aimed to investigate the relationship between off-flavor compounds and differentially expressed proteins in a controlled O 2 /CO 2 atmosphere using headspace GC–MS fingerprinting and an iTRAQ-based quantitative proteomic approach. Results demonstrated that a suitably controlled O 2 /CO 2 atmosphere increased the energy production efficiency, improved stress resistance, and markedly extended the shelf life of broccoli heads. However, treatment with an excessively high CO 2 proportion promoted glycolysis and fermentation, reduced energy generation efficiency, altered sulfur-component metabolism, and promoted the accumulation of an offensive odor in broccoli heads. This study provides a foundation for understanding the metabolic mechanisms responsible for off-flavor and highlights potential control measures under high CO 2 conditions.