Tororo (food)

For the Ugandan region, see Tororo. For the root for papermaking, see Abelmoschus manihot. For the Sgt. Frog character, see Tororo (Sgt. Frog). For the district, see Tororo District.

Tororo

Soba with tororo
Type	Side dish, food staple
Place of origin	Japan
Associated cuisine	Japanese cuisine
Serving temperature	Cold
Main ingredients	Yamaimo or nagaimo, water
Media: Tororo

Tororo (Japanese: 薯蕷, とろろ) is a Japanese side dish made from grating raw yams such as yamaimo or nagaimo. Usually flavorless, ingredients that can be mixed with it can be wasabi, dashi, and chopped spring onions, to give it more flavor.

Both the yamaimo and nagaimo varieties belong to the same genus of species, but when making the dish the two, and other yams used for the food, are collectively called yamanoimo (ヤマノイモ), meaning wild yams.

Etymology

The term tororo (とろろ), comes from the Japanese sound symbolism of torotoro (トロトロ or とろとろ), which expresses that something is sticky, slimy, or syrupy.

In Japanese grammar, onomatopoeias usually function as adverbs, though they can also function as verbs with the auxiliary verb suru (する, "do"); with torotorosuru (とろとろする or トロトロする), meaning the state of a solid object turning into a viscous liquid.

Production

Nagaimo (literally "long tuber"), also known as Chinese yam, a yam used for making tororo

The yams that are used in the process of making tororo, such as yamaimo and nagaimo, must be tubers that are edible when eaten raw. Many other varieties such as cassava, taro, and potatoes, must be prepared by peeling and boiling them thoroughly before consumption as these contain amounts of calcium oxalate in the form of crystals, which are shaped like needles, which can be found on the plant's peel, tissue, leaf, stem, root, and anthers, can cause intense pain and swelling if they come in contact with the skin and mouth.

Grated tororo using a modern grater

Before grating, the yam's roots and the peel are removed to avoid itchiness from the calcium oxalate crystals present on those parts of the plant. Even though they possess calcium oxalate crystals, they are not present on the pith unlike other tubers.

Traditional grating uses a suribachi, grinding the yam along the surface of it slowly until the amount of yam present on it is enough so that a surikogi can mix it by lifting it to incorporate air for a more viscous texture. Many modern processes of making tororo uses a grater for a faster process.

Tororo is usually plain but other ingredients such as soy sauce, dashi, and miso, are added for other recipes such as mugitoro and suitoro to enhance the flavor and change the texture.

Texture

The stickiness of tororo gets prevalent during grinding, which is said to be the mucilage found in the yam dissolving the cells by grinding and hydrating them. Another theory suggests that grinding the yam makes it stickier, which also happens when the grinded up yam is cooked. The chemical composition of the mucilage has not yet been found. Theories from the Chemical Society of Japan suggest that the substance is made of mannans and proteins, same characteristics when Ginkgo biloba is ground.

Nutrition

Mugitoro gohan, a dish used in the study

The main ingredient of tororo (yams), contains a high amount of vitamins and minerals such as thiamine (vitamin B1), vitamin C, calcium, and potassium. As well as micronutrients such as potassium, zinc, and iron.

In a study by the Asia Pacific Journal of Clinical Nutrition, the consumption of tororo has a multitude of health benefits to the human body, such as the lowering of blood glucose and insulin which may contribute to the prevention of diabetes, obesity and cardiovascular diseases. Although due to the raw nature of the food, it is more difficult to digest and absorb nutrients due to the presence of mucin, dietary fiber, and uncooked raw starch in tororo.

Uses in food

Yamakake, hamachi over tororo

Tororo is served cold and is consumed on its own though, the foodstuff can also be used as a side dish for other dishes or as an ingredient to other dishes. It is usually flavorless but other condiments such as wasabi, dashi, miso, and chopped spring onions are added for flavor or for other dishes.

Tororo is often used as a topping on many dishes due to their, many foods such as nattō, udon, and fish can be topped with tororo for a more filling meal as it is inexpensive to add. When tororo is accompanied with fish (usually tuna), the dish is called yamakake.

Soba with tororo

One of these foods is called mugitoro gohan (also known as tororo-meshi and tororo-kake-meshi when made), a dish made by pouring tororo over barley rice. The dish has been proven to help people maintain blood sugar and improves stamina.

Many soups such as soba noodle soups are paired up with tororo. Tororo is mixed up with ingredients such as soy sauce, miso, and dashi before being put as an ingredient into a soup called tororo-jiru to add more flavor. Mugitoro gohan is often paired up with soup, with the combination being called kotozute-jiru.

Depictions in art and literature

Tororo-jiru depicted in an ukiyo-e of Mariko-juku, one of the stations in the 53 Stations of the Tōkaidō

Tororo is referenced in literary works such as the Seisuishō, a book made by Anrakuan Sakuden in 1623, coining the term kotozute-jiru (literally meaning word soup), from the double meaning of the word iiyaru which can mean to say (using words) or to eat.

In the Edo period, Mariko-juku, one of the stations in the 53 Stations of the Tōkaidō, tororo-jiru is known as a famous local food in the area. Matsuo Bashō, the most famous poet during the Edo period wrote a poem about the local specialty entitled Ume-wakana Maruko no Yado no Tororo-Jiru in his anthology Sarumino. It is written as a specialty of the area in the Tōkaidōchū Hizakurige.

Featured on the ukiyo-e prints by Hiroshige, The Fifty-three Stations of the Tōkaidō, one print features Mariko-juku, the 20th station of the Tōkaidō, of a teahouse serving tororo-jiru.