Among the polyunsaturated fatty acids of human milk, arachidonic (AA)
and docosahexaenoic acid (DHA) are of particular physiological importa
nce. For this reason, the triglycerides (TG) containing polyunsaturate
d fatty acids were isolated by argentation HPLC and were partially fra
ctionated further by HPLC on a RP-18 column. The position analysis of
the TG obtained using partial hydrolysis with Grignard reagent indicat
es that AA and DHA are rather evenly distributed over the marginal and
central TG positions. As a consequence, the positional distribution o
f these fatty acids can be neglected for supplementing polyunsaturated
fatty acids in infant formulas. Several fish oils with high DHA but l
ow eicosapentaenoic acid contents and some single cell oils containing
DHA and AA in high concentrations were analysed as well and proved to
be very suitable for supplementation purposes.