9種の貝の脂肪酸組成について

抄録

For analysis of fatty acid composition nine common and marketable species of shellfish were selected in January, 1963, at Tsukiji Wholesale Market, Tokyo. Total sterol content was determined as cholesterol by the Sperry-Schoenheimer modification of the Liebermann-Burchard reaction. An average of 93mg of sterol was found per 100g of viscera-free tissue (Table 1).
Fatty acids were analyzed on a gas-chromatograph equipped with a diethylene glycol suc-cinate polyester column (Fig. 1). Table 2 shows the relative retention volumes of standard fatty acids. On chromatograms of samples, three peaks appeared having relative retention volumes of 81.5, 405, and 610. From chromatograms of the urea complex filtrate and unsa-ponifiable matters, these peaks were presumed to be C₁₈ aldehyde, C_22:2 and C_22:4 fatty acids, respectively (Table 3, Figs. 2 and 3).
Although each species of shellfish showed its own pattern of fatty acid composition as shown in Table 4, general aspects of all patterns could be summarized as follows:
1) C₁₅ odd acid was recorded at 2.3-4.9 per cent as much as C₁₄ saturated acid.
2) The level of C₁₆ saturated acid, which was found as the largest component in seven out of the nine samples, was 30 per cent in hen clam and nearly 20 per cent in other samples. C_l8:1 and C_22:6 fatty acids, which are often found in large quantities in fish muscle lipids, contributed less than 20 per cent of the total.
3) Among the species tested, top-shell, abalone, and kid-abalone belong to gastropoda and take seaweeds as their food, while six others belong to pelecypoda and are known as plankton feeders. Between these groups, the seaweed feeders had larger amounts of C_20:4 and C_22:5 fatty acids than the plankton feeders, but in case of C_22:6, vise versa.