Maintenance of total glucosinolate levels in kale and cabbage leaves when stored under light/dark cycles. Glucosinolate species was quantified from leaf disks of kale (A) and cabbage (B) stored under cycles of 12-hour light/12-hour darkness (LD, half-filled circles), constant light (LL, open squares), or constant darkness (DD, filled squares) at 22°C or under constant darkness at 4°C (4CDD, filled diamonds). Mean ± SE; n = 4. Asterisks indicate significant differences (p < 0.05. ANOVA Test with Bonferroni Post Hoc analysis) between samples kept in light/darkness cycles (22°C) and those stored in constant light (22°C), constant dark (22°C) and under constant darkness (4°C) for a specified time point. Statistical analyses of differences over time for each plant type are shown in Additional file 1: Figure S6.