Konjac (Glucomannan)
What it does
Thickener; used in some noodles.
How it's made
From konjac root.
Konjac (glucomannan) is a natural thickener and gelling agent made from the tuber (corm) of the konjac plant (Amorphophallus konjac), grown in East Asia. It is an exceptionally powerful thickener and is used in noodles, jelly desserts and, because it is a fibre, in some fibre-enriched and slimming foods. It is the basis of shirataki noodles.
It is obtained by peeling, slicing and drying the konjac corm, then milling it and separating out the fibre-rich glucomannan flour from the starch and other components. Further purification concentrates the glucomannan, a carbohydrate that absorbs a very large amount of water.
The purified konjac flour is standardised for use. It swells enormously in water and, with the right treatment (often with a mild alkali), forms a firm, heat-stable gel; because it can absorb so much water it is used in tiny amounts, and its status as a dietary fibre is why it appears in low-calorie foods, though konjac jelly sweets are made in shapes and sizes designed to avoid choking risks.
Possible reactions
Choking risk in gel/jelly form (banned as mini-cup jellies); very filling.