Friday, April 04, 2008
Diet & Nutrition
Brocolli, Over Boiling Kills Anti-Cancer Properties
Steam, don't boil! 30 minutes boiling reduces anti cancer agent glucosinolate by 77%!!
The researchers, Prof Paul Thornalley from Warwick Medical School at the University of Warwick and Dr Lijiang Song from the University of Warwicks Department of Chemistry bought Brassica vegetables, (broccoli, Brussel sprouts, cauliflower and green cabbage) from a local store and transported them to the laboratory within 30 minutes of purchasing. The effect of cooking on the glucosinolate content of vegetables was then studied by investigating the effects of cooking by boiling, steaming, microwave cooking and stir-fry.
Boiling appeared to have a serious impact on the retention of those important glucosinolate within the vegetables. The loss of total glucosinolate content after boiling for 30 minutes was: broccoli 77%, Brussel sprouts 58%, cauliflower 75% and green cabbage 65%.
The effects of other cooking methods were investigated: steaming for 020 min, microwave cooking for 03 min and stir-fry cooking for 05 min. All three methods gave no significant loss of total glucosinolate analyte contents over these cooking periods.