I couldn’t find any specifics in the literature, but just based on broccoli & cauliflower experience, I suggest that you blanch florets (approx.

The CO2 and CO levels will not detrimentally affect the quality of the broccoli, however storage at 10C for 4-5 days will result in some loss of nutrients even if yellowing is not

The nutrient content unfortunately degrades every day, at different rates depending on the storage temperature.

The green color of freshly harvested broccoli is due to the green pigment, chlorophyll. When you heat chlorophyll it may be changed into a yellow or 'pea green' pigment.