Marine lipids
Fatty acid composition of Skeletonema costatum
Polyunsaturated fatty acids (PUFAs) represented 76.4% of the total fatty
acids in Skeletonema costatum. The main PUFAs were 20:5 (n-3) (35.6%)
and C16 PUFAs (30.1%). The major C16 PUFAs were identified as
16:2 (n-4), 16:3(n-4) and 16:4 (n-1) (4.8%, 12.4% and 12.9%, respectively). The acid 22:6 (n-3) was a minor fatty acid in unicellular algae
(4% of the total fatty acids). The monounsaturated and saturated fatty
acids were also present in small proportions (9.7% and 13.6%, respectively). The fatty acid, 16:1 (n-7) was the main monounsaturated
fatty acid (8.6%) while 14:0 was the main saturated fatty acid (9.4%).
This composition is close to those previously reported for Skeletonema
costatum (Ackman et al., 1964; Chuecas & Riley, 1969; Volkman et al.,
1989; Dunstan et al., 1994; Bergé et al., 1995).
Changes in fatty acid composition of oysters supplemented
with Skeletonema costatum
No significant change was observed in the fatty acid composition of the
control group during the six weeks of experimentation. At all stages
studied (W1, W2, W3, W4 and W6) the latty acid composition was
close to that of oysters at the beginning of the experiment (W0). The
fatty acid composition of these oysters was characterized by a high proportion of PUFAs (51.8% ) (table 2). The major PUFAs were 20:5 (n-3)
and 22:6 (n-3), which accounted for 18.2% and 17.8% of the total
PUFAs content, respectively. In contrast to the results obtained for Skeletonema costatum, C16 PUFAs were detected in relatively small concentrations (less than one per cent). The proportion of (n-6) PUFAs was found
to be low (4.4%). A small proportion of C22 non-methylene-interrupted dienoic fatty acids was detected (5.0%). The saturated and
monounsaturated fatty acids represented 28.3% and 19.1% of total
fatty acids, respectively. The 16:0 and 18:0 fatty acids were the main
saturated fatty acids detected while the main monounsaturated fatty acids
were found to be 18:1 and 20:1.
116
Fatty acid composition of Skeletonema costatum
Polyunsaturated fatty acids (PUFAs) represented 76.4% of the total fatty
acids in Skeletonema costatum. The main PUFAs were 20:5 (n-3) (35.6%)
and C16 PUFAs (30.1%). The major C16 PUFAs were identified as
16:2 (n-4), 16:3(n-4) and 16:4 (n-1) (4.8%, 12.4% and 12.9%, respectively). The acid 22:6 (n-3) was a minor fatty acid in unicellular algae
(4% of the total fatty acids). The monounsaturated and saturated fatty
acids were also present in small proportions (9.7% and 13.6%, respectively). The fatty acid, 16:1 (n-7) was the main monounsaturated
fatty acid (8.6%) while 14:0 was the main saturated fatty acid (9.4%).
This composition is close to those previously reported for Skeletonema
costatum (Ackman et al., 1964; Chuecas & Riley, 1969; Volkman et al.,
1989; Dunstan et al., 1994; Bergé et al., 1995).
Changes in fatty acid composition of oysters supplemented
with Skeletonema costatum
No significant change was observed in the fatty acid composition of the
control group during the six weeks of experimentation. At all stages
studied (W1, W2, W3, W4 and W6) the latty acid composition was
close to that of oysters at the beginning of the experiment (W0). The
fatty acid composition of these oysters was characterized by a high proportion of PUFAs (51.8% ) (table 2). The major PUFAs were 20:5 (n-3)
and 22:6 (n-3), which accounted for 18.2% and 17.8% of the total
PUFAs content, respectively. In contrast to the results obtained for Skeletonema costatum, C16 PUFAs were detected in relatively small concentrations (less than one per cent). The proportion of (n-6) PUFAs was found
to be low (4.4%). A small proportion of C22 non-methylene-interrupted dienoic fatty acids was detected (5.0%). The saturated and
monounsaturated fatty acids represented 28.3% and 19.1% of total
fatty acids, respectively. The 16:0 and 18:0 fatty acids were the main
saturated fatty acids detected while the main monounsaturated fatty acids
were found to be 18:1 and 20:1.
116