palatability of the dashi broth created from kombu, and was a distinct sensation from sweet, sour, bitter, and salty tastes. Ikeda named the newly-discovered taste umami (うま味), from the Japanese word umai (うまい, "delicious"). Since the 1960s, dried kombu has been exported from Japan to many countries. It was available initially at Asian, and especially Japanese, food shops and restaurants, and can be found in supermarkets, health-food stores, and other nonspecializing suppliers. Cooking Japan Kombu is sold dried (dashi konbu) or pickled in vinegar (su konbu) or as a dried shred (oboro konbu, tororo konbu or shiraga konbu). It may also be eaten fresh in sashimi. Kombu is used extensively in Japanese cuisines as one of the three main ingredients needed to make dashi, a soup stock. Konbu dashi is made by putting either whole dried or powdered kombu in cold water and heating it to near-boiling. The softened kombu is commonly eaten after cooking or is sliced and used to make tsukudani, a dish that is simmered in soy sauce and mirin. Kombu may be pickled with sweet-and-sour flavoring, cut into small strips about 5 or 6 cm long and 2 cm wide. These are often eaten as a snack with green tea. It is often included when cooking beans, putatively to add nutrients and improve their digestibility. Konbu-cha or kobu-cha () is a tea made by infusing kombu in hot water. What Americans call kombucha is called "kōcha kinoko" in Japan. Kombu is also used to prepare a seasoning for rice to be made into sushi. Nutrition and health effects Kombu is a good source of glutamic acid, an amino acid responsible for umami (the Japanese word used for a basic taste identified in 1908). Several foodstuffs in addition to kombu provide glutamic acid or glutamates. Kombu contains extremely high levels of iodine. While this element is essential for normal growth and development, the levels in kombu can cause overdoses; it has been blamed for thyroid problems after drinking large amounts of soy milk in which kombu was an additive. It is also a source of dietary fiber. Algae including kombu also contain entire families of obscure enzymes that break down complex sugars that are normally indigestible to the human gut (thus gas-causing), including the well-studied alpha-galactosidase and beta-galactosidase. Biofuel Genetically manipulated E. coli bacteria can digest kombu into ethanol, making it a possible maritime biofuel source. See