showed no significant variation at harvest (Table 1). However, during storage the changes in color were markedly different between primary and secondary heads. Terminal florets showed almost no variation in the Hue angle throughout the storage period as opposed to lateral broccoli which showed a rapid decrease of Hue values as the florets yellowed. The Hue angle is highly correlated with total chlorophyll content of broccoli florets (Tian et al., 1994). The loss of green color in lateral broccoli was also depicted from the large increase observed in lightness. Broccoli from secondary heads showed increased L* values in storage as opposed to primary heads in which changes were limited (Table 1).
Noteworthy, after 3 weeks, the fresh cut-product from primary heads were greener than florets from secondary heads stored only for 14 d. The concentration of chlorophyll in primary and secondary heads at harvest was similar (Table 2). During the refrigerated storage a rapid loss of chlorophylls was found in secondary florets. At the end of the storage period primary broccoli maintained higher chlorophyll levels (1.2 fold) than secondary florets. This was due to a decreased degradation of both Chl a and b (Table 2).