Rabarber tegen kanker*
Rabarber staat al bekend om zijn gezonde bioactieve stoffen die goed zijn in de bestrijding van
kanker. Het betreft dan de antioxidanten en anthocyanen. Het koken of smoren van rabarber doet deze bioactieve stoffen aanzienlijk vermeerderen. 20 minuten koken doet hun aantal fors vermeerderen. Langer koken is niet zinvol omdat daardoor deze gezonde stoffen weer afbreken.
Baked Rhubarb Could Help Fight Cancer
Eating rhubarb baked in a crumble is not only tasty it may also be the best way to take advantage of its health benefits, and could lead to the development of new cancer treatments.
Researchers have found that baking British garden rhubarb for 20 minutes dramatically increases its levels of anti-cancerous chemicals. The findings from academics at Sheffield Hallam University, together with the Scottish Crop Research Institute, were published in the journal Food
Chemistry.
These chemicals, called polyphenols, have been shown to selectively kill or prevent the growth of cancer cells, and could be used to develop new, less toxic, treatments for the disease, even in cases where cancers have proven resistant to other treatments.
Academics are now hoping to use the results to study the effect of rhubarb's polyphenols on leukaemia. They aim to discover the best combination of polyphenols and chemotherapy agents to kill leukaemia cells, even those previously resistant to treatment.
It is the first time the benefits of British garden rhubarb, specifically a variety grown in South Yorkshire, have been studied. Previous research has focussed on Oriental medicinal rhubarb, which has been recognised for its health benefits and used in traditional Chinese medicine for thousands of years.
Dr Nikki Jordan-Mahy, from Sheffield Hallam University's Biomedical Research Centre, said: "Our research has shown that British rhubarb is a potential source of pharmacological agents that may be used to develop new anti-cancerous drugs".
"Current treatments are not effective in all cancers and resistance is a common problem. Cancer affects one in three individuals in the UK so it's very important to discover novel, less toxic, treatments, which can overcome
resistance."
Effect of different cooking regimes on rhubarb polyphenols
Gordon J. McDougalla, , , Pat Dobsona and Nikki Jordan-Mahyb
aPlant Products and Food Quality Programme, Scottish Crop Research Institute (SCRI), Invergowrie, Dundee, Scotland DD2 5DA, UK
bBiomedical Research Centre, Sheffield Hallam University (SHU), Howard Street, Sheffield S1 1WB, UK
Abstract
Polyphenolic components, such as anthraquinones and stilbenes, from species of the genus Rheum have been shown to have a range of bioactivities relevant to human health. This paper outlines the polyphenolic composition of edible petioles of garden rhubarb (Rheum rhapontigen) and describes the effects of common cooking methods on total polyphenolic content, anthocyanin content and total antioxidant capacity.
Most cooking regimes (fast stewing, slow stewing and baking) except blanching increased total polyphenol content and overall antioxidant capacity, compared to the raw material. The patterns of anthocyanin content and total polyphenol content between the different cooking regimes suggested a balance between two processes; cooking facilitated the release of polyphenol compounds from the rhubarb but also caused breakdown of the released compounds.
Baking and slow stewing offered the best maintenance of colour through preservation of anthocyanin and the highest antioxidant capacity. Baking for 20 min provided well-cooked rhubarb with the highest antioxidant capacity and the highest anthocyanin content, which is important for the aesthetic quality of the dish.
Liquid chromatography-mass spectrometric (LC-MS) analysis putatively identified over 40 polyphenol components in raw rhubarb, including anthraquinone, stilbene, anthocyanin and flavonol derivatives. Baking caused selective effects on the stability of the different polyphenol components. Initially, the yield of all components increased but there was a drastic decline in the relative stability of anthraquinone aglycones with increasing cooking time and initial evidence for the turnover of other anthraquinone derivatives was obtained.
Source: Sheffield Hallam University (April 2010)
