SEASONAL-VARIATION IN THE LIPID-CONTENT OF CULTURED LAMINARIA-JAPONICA - FATTY-ACIDS, STEROLS, BETA-CAROTENE AND TOCOPHEROL

Seasonal variation in major lipid constituents of nutritional importance in cultured Laminaria japonica Aresch., such as fatty acids, sterols, beta-carotene and tocopherol, were investigated from December to October, the growing season.The total and saturated fatty acid contents were minimal in midsummer. Mono-unsaturated fatty acids gradually increased from late summer to autumn. The polyunsaturated fatty acid content (PUFA, (n-6) family) was maximal during warm months, while (n-3) PUFAs were most abundant during the cold months when algal thalli were very young, and decreased gradually toward October when sori had developed. Fucosterol content was maximum from February to June, but decreased steeply by nearly a half toward October, when 24-methylene cholesterol was highest although much less than fucosterol. The beta-carotene and tocopherol contents were maximal from July to September and slight during the winter.