Abstract:

The effect of ethanol vapor treatment on bioactive compounds, such as total phenols, flavonoids, total
glucosinolates and sulforaphane, and antioxidant activity of fresh-cut broccoli florets was investigated. The broccoli heads
were pretreated with 2%, 5%, 10% or 20% ethanol vapor at 20 ℃ for 6 h, then cut into small florets and stored at 10 ℃
for 10 days. The results showed that pretreatment with 10% ethanol significantly prolonged the shelf life of fresh-cut
broccoli, increased the contents of total phenols and flavonoids, delayed the decrease in the contents of total glucosinolates
and sulforaphane. This treatment also effectively maintained higher DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical
scavenging activity and reducing power, improved superoxide anion and hydroxyl free radical scavenging ability, thereby
delaying postharvest senescence and maintaining higher antioxidant activity of fresh-cut broccoli florets. Meanwhile, it
was found that there was a significant positive relationship between the contents of total phenols, flavonoids, glucosinolates
and DPPH free radical scavenging activity. These results demonstrate that ethanol treatment may be a promising method to
extend the shelflife and maintain the nutritional quality of fresh-cut broccoli.

Key words: fresh-cut broccoli, ethanol vapor treatment, bioactive components, antioxidant activity