Hijiki (tot)

Tot (hijiki, listed in the Encyclopedia of Korean Culture as Hizikia fusiforme) is a perennial brown seaweed of the mojaban (sargassum) family. Young plants have flat, toothed leaves; mature ones are a tangle of cylindrical branchlets, some swollen into air bladders. It grows on gently sloping rock just below mean sea level on open coasts, sprouting in autumn, growing fast from March and reaching 60 cm or more, often over a meter off Jeju, before reproducing and dying back in early summer. Old texts call it toeuichae, and nokmichae ("deer-tail greens") for its shape; on Jeju it is tol. It is brown on the rock, black when dried, and turns green when blanched.

Jeju and the southwest coast are its home. According to the Encyclopedia of Korean Folk Culture, growers in South Jeolla began cultivating plants from Jeju stock in the 1980s, and farmed tot now dominates; Jindo's Jodo islands (Gwanmaedo, Gwansado) and Wando's Cheongsan islands are prime farming grounds. Because full hatchery cultivation has not been achieved as it has for gim and miyeok, farmers collect wild holdfasts and seed them on ropes. Most of the crop is sold dried, and for decades almost all of it was steamed, dried and exported to Japan.

On the Korean table, tot is mainly a muchim: blanched and dressed with gochujang in Gangwon, doenjang on Jeju and in Jeolla, or anchovy sauce in South Gyeongsang, sometimes with radish, cucumber, bean sprouts or tofu. Islanders also stretched scarce grain in the hungry spring months with totbap, rice cooked with hijiki, which some restaurants now serve as a health dish. Dried tot is soaked in cold water and blanched before use.

• Calcium and iron: Raw tot in the Korean table has 157 mg of calcium and 3.9 mg of iron per 100 g, and the dried product is far more concentrated.
• Inorganic arsenic: Hijiki accumulates much more inorganic arsenic, a suspected human carcinogen, than other seaweeds. The Canadian Food Inspection Agency advises consumers to avoid hijiki, saying a small amount could exceed the tolerable daily intake.
• Soak, boil, discard the water: Korea's Ministry of Food and Drug Safety found soaking and boiling removed over 80 percent of inorganic arsenic (average 3.3 to 0.7 mg/kg). It advises blanching fresh tot 5 minutes, soaking dried tot 30 minutes then boiling 30 minutes, and never cooking with the soaking water.
• Iodine: As with other seaweeds, MedlinePlus cautions that very high iodine intake can reduce thyroid function.