Daikon

Daikon, a promising anti-cancer vegetable

RIRDC Project No DAQ-342A, June 2007,  Dr Tim O’Hare Queensland Department of Primary Industries and Fisheries,

Queensland Horticulture Institute, Gatton Research Station

Objectives

Identify daikon and radish varieties with highest anti-cancer activity, following on from DAQ-307A which identified daikon and radish sprouts as having extremely high anti-cancer potential. Provide labelling advice in relation to the strongest possible claims that can be made.

Current Progress (June 2007)

Daikon and radish were analysed at the seed and sprouted-seed stage to identify cultivars high in the anti-cancer glucosinolate, glucoraphenin. Of the cultivars tested, ‘Cherry Belle’ and ‘Black Spanish’ maintained highest levels of glucoraphenin. Levels were highest in seed, and decreased with increasing sprout age. Decline in concentration was largely due to dilution associated with cell expansion, and partly due to other mechanisms. Differences in the latter appear to have impact on anti-cancer potential.

Analysis of mature daikon and radish tissue (roots and shoots) indicated that the principal glucosinolate in roots of all cultivars was glucodehydroerucin, which is estimated to have one tenth the potency of glucoraphenin, the principal glucosinolate found in seeds and young sprouts. By contrast, the principal glucosinolates present in mature shoots were glucoraphanin and glucoraphenin, both potent anti-cancer agents. Shoots were estimated to have approximately 20 times the anti-cancer potential of roots.

A scientific paper was presented at the International Horticultural Congress in Seoul (Korea) in August 2006 entitled: “Glucosinolate Composition and Anti-Cancer Potential of Daikon and Radish sprouts”. A poster presentation was made at the 6th Annual Health and Medical Research Conference of Queensland

(November, 2006).