Affiliations: INRA, URH, Center de Clermont Ferrand-Theix, 63122 St
Genès Champanelle, France. Tel.: +33 4 73 62 40 52; Fax: +33 4 73 62 42
73; E-mail: [email protected]
Note: [] Corresponding author
Abstract: Isoflavones that exist in forages such as clover can move in milk,
and may have beneficial effects on human health. We measured the isoflavones in
subterranean (cv Yarloop, Geraldton, Dinninup and Dwalganup) and red (cv
Merviot and Hamua) clovers, grown in a mountain environment, and in the milk of
two goats fed a fresh mixture of the four subterranean clovers gathered at
flowering stage. Isoflavone glycosides were hydrolysed with an improved
β glycosidase method. Free aglycones (FA) and the
hydrolysed glycosides + free aglycones fraction (HF) were
analysed by HPLC. In milk, the methanol extracted compounds were deconjugated
and similarly analysed. Total HF was highest in Yarloop (19~g
kg^{-1} dry matter) and was three times lower in Merviot.
Formononetin was the major compound (46–64% of total HF). FA varied from 30
to 73% of HF. Milk contained formononetin (50 μg
L^{-1}), similar amounts of equol and p ethylphenol (about
250 μg L^{-1}), and equol like
compounds (1120 μg L^{-1}). Equol,
which has estrogenic activity, and p ethylphenol were produced by
biotransformation of formononetin, and biochanin A or genistein, respectively.
The modulation of isoflavone amounts in milk and the estimation of their
interests for human health warrant further investigation.
