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 importan ce in cultured Laminaria japonica Aresch., such as fatty acids, sterol s, beta-carotene and tocopherol, were investigated from December to Oc tober, the growing season.The total and saturated fatty acid contents were minimal in midsummer. Mono-unsaturated fatty acids gradually incr eased from late summer to autumn. The polyunsaturated fatty acid conte nt (PUFA, (n-6) family) was maximal during warm months, while (n-3) PU FAs were most abundant during the cold months when algal thalli were v ery young, and decreased gradually toward October when sori had develo ped. Fucosterol content was maximum from February to June, but decreas ed steeply by nearly a half toward October, when 24-methylene choleste rol was highest although much less than fucosterol. The beta-carotene and tocopherol contents were maximal from July to September and slight during the winter.