In conclusion, current industrial pre-freezing processing and
freezing handling significantly reduced the content of glucosinolates,
while enhanced the levels of phenols, carotenoids and
chlorophyll, and thereby boosted the antioxidant capacity. The
reduction of glucosinolate content was mainly caused by blanching
and cooling treatment, and the elevation of total phenolic content
and antioxidant capacity was due to blanching and freezing. Carotenoids
content was substantially increased by freezing while
chlorophyll content was dramatically enhanced by blanching.
Although pre-freezing processing and freezing handling are good
approach to maintaining antioxidant ability of broccoli florets,
steam blanching and ice-water cooling are suggested to replace
the current blanching and cooling processing in common industrial
pre-freezing chain to minimize the reduction of glucosinolate
contents.