Keeping Green and Nutritious: A Comprehensive Review on Postharvest Handlings of Broccoli ( Brassica oleracea var. italica )

Broccoli is a nutrient-dense vegetable rich in phytochemicals. However, it is highly perishable due to its high respiration rate and ethylene sensitivity, leading to rapid yellowing and nutrient loss. Maintaining both visual appearance and nutritional integrity remains a major challenge in the postharvest supply chain. This review comprehensively summarizes the physiological, biochemical, and molecular mechanisms involved in postharvest senescence of broccoli, focusing on chlorophyll catabolism, oxidative stress, and glucosinolate metabolism. It critically evaluates recent progress in preservation technologies, emphasizing their underlying regulatory mechanisms and impacts on quality attributes. Visual and nutritional decline in broccoli are mechanistically interconnected rather than parallel processes. Senescence drivers, including ethylene and phytohormone crosstalk, as well as reactive oxygen species (ROS), promote chlorophyll degradation by regulating chlorophyll catabolic enzymes (CCEs) and chlorophyll-degradation peroxidase (Chl-POX) and impairing chloroplast integrity via lipid peroxidation. They also disrupt cellular integrity, allowing glucosinolates to contact degrading enzymes and accelerate their degradation. Meanwhile, hormone crosstalk regulates glucosinolate metabolic genes, resulting in decreased glucosinolate content. Based on these insights, postharvest strategies can delay senescence and preserve quality by targeting these drivers, such as by inhibiting ethylene action, enhancing antioxidant systems, and regulating hormone crosstalk. Overall, this review highlights promising technologies to maintain the green color and nutritional value of broccoli, ensuring high-quality and residue-free produce.