Shirataki

Shirataki (しらたき) is a thin, translucent Japanese noodle made from konjac: a gel made from the konjac corm and set with a coagulant. Its base is glucomannan (in EU legislation 'konjac mannan'), a polysaccharide of glucose and mannose, not starch, so shirataki does not belong to the starch noodles such as fensi.

The raw material is the konjac taro, a plant that takes several years to reach harvest, is sensitive to weather and pests and grows best in a mild climate with good drainage. Japan's agriculture ministry (MAFF) writes that it probably reached Gunma Prefecture in the Muromachi period and that volcanic soil and a moderately dry climate helped it settle. Today Gunma supplies over 90 % of Japan's konjac taro (MAFF data of June 2020). By the same source most supermarket konjac is made from powder, while in Gunma it is also made from fresh taro, which gives a firmer, crunchier texture.

Shirataki and itokonnyaku are essentially the same thing. According to the Japan Konjac Association, in the Edo period in the west, Kansai, thin strips were cut from slabs of konjac and called itokonnyaku, while in the east, Kanto, the mass with coagulant was pushed into hot water in thin streams and called shirataki. Today both regions make the noodle the shirataki way, and only the name differs.

Europe has its own rules for glucomannan. Regulation (EU) 432/2012 permits two claims: that glucomannan contributes to the maintenance of normal blood cholesterol (for a food providing 4 g a day), and that in the context of an energy-restricted diet it contributes to weight loss (for a food containing 1 g of glucomannan per portion, with advice to take 3 g a day in three doses of 1 g with 1–2 glasses of water before meals). For such foods the regulation requires a choking warning for people with swallowing difficulties and advice to take plenty of water.

Why it matters to you. Shirataki is neither a starch noodle nor a 'diet food' by itself: the EU claims about glucomannan are allowed only for foods that meet the stated conditions.