Preparing cassava and bamboo shoots to eat
(Last updated October 2011)
Cassava and bamboo shoots are safe to eat provided you prepare them properly.
Cassava
Cassava is a tropical root crop similar to taro and yam and is grown for food in Pacific Island countries, South America, Asia and Africa. It has enlarged starch-filled roots, which contain about 30% starch and very little protein. It is also known as yucca, tapioca (in a processed form), gaplek or manioc.
Raw cassava contains cyanogenic glycosides, which break down to release toxic hydrogen cyanide. Most raw or unprocessed cassava imported into Australia and New Zealand from the Pacific Islands is sweet cassava, which normally has a low cyanide content.
Bitter cassava is not commercially traded because it usually contains higher levels of cyanogenic glycosides, requiring more extensive processing to remove these and prevent hydrogen cyanide formation.
To make cassava safe to eat, f irst peel and slice the cassava and then cook it thoroughly either by baking, boiling or roasting. This process removes the toxins. Frozen cassava and frozen peeled cassava should also be prepared in this way.
Processed cassava such as cassava chips, cassava flour and tapioca pearls used for tapioca pudding, is also safe with a long history of human consumption.
However, in 2008 concerns about the safety of very young children eating ready-to-eat cassava chips prompted FSANZ to assess the chips and set a maximum limit of 10 mg/kg of hydrogen cyanide.
Bamboo shoots
Bamboo shoots are another traditional Asian food and are safe to eat as long as they are prepared properly.
They are sourced from the underground stems of the bamboo plant. However, of the many species of bamboo, only a small number are used as food.
Like cassava, unprocessed fresh bamboo shoots contain cyanogenic glycosides.
To make them safe, slice fresh bamboo shoots in half lengthwise, peel the outer leaves away and trim any fibrous tissue at the base. Then slice them thinly into strips and boil in lightly salted water for eight to ten minutes.
The most common preparation involves boiling the shoots in stocks, soups or salted water.
As Asian dishes increase in popularity in Australia and New Zealand, using fresh bamboo shoots rather than canned has become increasingly common.
However, canned or dried bamboo shoots are widely available and present little or no public health and safety risk since processing removes hydrogen cyanide.
Ready-to-eat cassava chips approval report (PDF 662 KB)