Abstract: Fresh-cut broccoli florets are very susceptible to yellowing, which seriously affects their sensory quality and commercial value. In order to slow down the yellowing of fresh-cut broccoli florets and prolong the storage period, the effect of fluorescence irradiation (24 μmol/(m2·s), 12 h/d) on the senescence and yellowing of fresh-cut broccoli were studied by ion chromatography analysis. The results showed that light treatment significantly maintained the chlorophyll content and reduced the yellowing index of fresh-cut broccoli in comparison to dark control (P < 0.05). Meanwhile, light irradiation induced the accumulation of glucose, sucrose, and fructose, increasing by 106%, 73%, and 70% from day 0 to 5, respectively. The content of endogenous glucose in fresh-cut broccoli pronouncedly increased with increasing concentration of exogenous glucose up to 120 mmol/L. In addition, yellowing index markedly declined (P < 0.05), and it was significantly negatively correlated with exogenous and endogenous glucose concentration with correlation coefficients of ?0.958 and ?0.878, respectively (P < 0.01). Therefore, fluorescence irradiation can retard the senescence and yellowing of fresh-cut broccoli florets presumably inducing the accumulation of soluble sugars, especially glucose.

Key words: senescence, fluorescence, preservation, chlorophyll, soluble sugars