Abstract
Regarding aluminum contents in sea vegetables, dried hijiki (an edible brown algae), dried wakame (seaweed) and dried konbu (kelp) contained 1.08mg/g, 17.7 to 149μg/g, and 4.23 to 24.5μg/g, of aluminum, respectively. With hijiki, especially, having a high aluminum content. Hijiki reconstituted by water immersion contained 450 to 678μg/g, of aluminum. Thus, aluminum in dried hijiki was decreased by 40 to 66% by water immersion. The immersion water of blanched and salted wakame and fruit-bearing leaf wakame contained 4.67 to 6.92μg and 1.00μg of aluminum, respectively. The migration ratio of aluminum was 8-12% for blanched and salted wakame and was 1% for fruit-bearing leaf wakame. The immersion water of Hidaka konbu contained 16.1 to 21.4μg of aluminum, while that of Rishiri konbu contained 4.79 to 7.36μg of aluminum. Thus, 22 to 57% of aluminum migrated into the konbu immersion water. Aluminum scarcely migrated into the supernatant of the immersion water. Compared with the cold water immersion method, a high aluminum migration ratio was achieved in the heat extraction method. It was estimated that the aluminum intake from reconstituted hijiki (dry weight: 5g) was about 2.2 to 3.4mg, which amounted to 50 to 75% of the daily aluminum intake of a typical Japanese diet.
