For respiration measurements, broccoli florets held at 20 C for 2 h until reaching room temperature, weighing approximately 150 g were placed in a 3 L lask, sealed and incubated for 15 min at 20 C (to prevent CO2 levels over 1% which would affect the respiration rate). CO2 concentration in the headspace was determined using an infrared analyzer (Alnor, CompuFlow Model 8650 MN, USA). Results were expressed as rate of CO2 evolution in mg kg1 s1. Three samples from different florets were analyzed for each inflorescence type and sampling date.