Marine brown algae fromthe coast ofCalifornia are
very large seaweeds. Therefore, we compared the FA
composition in fronds and stipes ofMacrocystis integrifolia
±oneof themostwidelyusedPhaeophyta(Chapman
and Chapman 1980). We found that fronds and
stipes of this alga differed in their FAratios. The stipes
contained a greater proportion of saturated FAs
(26.9+2.0%) and total n-6 PUFAs (26.9+1.8% of
total FAs) than the fronds (20.1+1.1% and 19.1+
1.2%, respectively). The greatest variations in the FA
ratio between stipes and fronds of M. integrifolia were
found for PUFAs of the n-3 series (18:3, 18:4 and 20:5)
andoleic acid.Theproportionofn-3PUFAswas higher
in fronds,where they accounted for 48.8+3.1%of the
total FAs, whereas the concentration of these FAs was
lower in stipes (20.8+1.6%). On the contrary, the
stipes of this alga were richer in oleic acid (18.4+
1.1%)ascomparedwithfronds(6.7+0.9%).Asimilar
differenceintheFAratiosbetweendifferentpartsofthe
algal thallus has been reported for Laminaria japonica
Areschoug fromthe Sea of Japan (Khotimchenko and
Kulikova 2000) and Ecklonia muratii Feldmann from
the Senegalese coast (Miralles et al. 1989). Thus, these
results show that the highest amounts of n-3 PUFAs in
these brown algal specie sareconcentrate din the fronds.