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MHS Library | How can chemical principles be applied to create a more sustainable future?

Investigation topic 3: The chemistry of Aboriginal and Torres Strait Islander peoples’ practices

Throughout history, people all over the world have hypothesised, experimented, made empirical observations, gathered evidence, recognised patterns, verified through repetition, and made inferences and predictions to help them to make sense of the world around them and their place within it. Recent research and discussion have confirmed many Aboriginal and Torres Strait Islander groups use the environment and its resources to solve the challenges they face in the different Australian climates in ways that are more sustainable than similar materials produced in Western society. Their solutions can be explained by a variety of organic and non-organic chemical processes.

Questions that may be explored in this investigation include:

· What are the chemical processes that occur when Aboriginal and Torres Strait Islander peoples detoxify poisonous food items: for example, the preparation of nardoo as a food source by heating, and the detoxification of cycad seeds through the removal of cycasins?

The development of complex detoxification processes by the rainforest Aboriginal peoples of North Queensland was undoubtedly driven by the food needs of the society at the time. The recognition of patterns in data, gathered from experiments that attempted to remove toxins, allowed this cultural group to modify and perfect the detoxification processes. Since Europeans survived a near-fatal experience after consuming under-processed cycad kernels on the first voyage to Australia by Cook and his party in 1770, many of the detoxification processes of poisonous plant foods employed by Aboriginal peoples throughout Australia have been documented. These detoxification processes provide evidence of Australia's First Nations peoples’ extensive scientific knowledge of chemical and physical processes, and an acute ability to draw conclusions that are consistent with evidence. 

You can explore a great variety of methods to remove toxins from poisonous foods as used by many of Australia’s First Nations’ peoples. A particularly suitable example for your investigation may be the method to detoxify cycad seeds employed by the rainforest Aboriginal people of North Queensland.  

By investigating the detoxification of cycads, you have the opportunity to gain a deeper understanding of the factors that govern the rate of chemical reactions, as well as to learn about and appreciate the highly developed science inquiry skills, ingenuity, and scientific knowledge of the rainforest Aboriginal peoples of North Queensland. 

The Australian curriculum. (n.d.). The Australian Curriculum (Version 8.4). https://australiancurriculum.edu.au/TeacherBackgroundInfo?id=56454

Wikipedia is a good place to start when learning about cycads.

 

ATSI Peoples and Removing Toxins From Food 

Australia’s first peoples ate a large variety of plants, most of which required some form of processing in order to be consumed easily and safely. Around 20-25 known species of plants that ATSI peoples consumed needed some form of complex processing. 

The complex processing required would often take a considerable amount of time and was needed in order to leach certain products and chemicals from the plant. Leaching is the process of extracting certain chemicals or products from the plant, in this case, the undesired toxins or unpalatable substances.

Cycads were a particularly useful plant for Australia’s first peoples. In certain regions they were found in abundance and they could regenerate quickly after a fire. There are many species of cycads in Australia and most are found in or around coastal areas, particularly within tropical rainforests.

ATSI Peoples and Removing Toxins from Food. (n.d.). ScienceFlip – A Resource for Students and Educators. https://www.scienceflip.com.au/

 

There are various traditional practices that were employed by Indigenous Australians and Islanders used to detoxify foods that would otherwise be poisonous.

This video looks at a few of these including the cycad which is a great example.

Food Preparation: Poison

The fruit of the cycad Macrozamia was exploited as an important food source in spite of its being highly toxic and carcinogenic. The Aboriginal People had developed methods of removing the toxins that allowed the cycad seeds to become a rich food source. Different groups had different methods of removing the toxins, but they all achieved the sand end, an edible, sustaining, fruit.

In 1 method the kernels are cut open and the toxins are leached out in water. When the process had been completed the kernels were ground into a powder like flower and backed to make cycad bread.

Other people used a method involving fermentation, leaving the kernels in large containers, or in some cases pits, where they remained for several months. They process is complete when the kernels have frothed or become mouldy.

Read the whole article.

Food preparation - Poison. (n.d.). A biography of the Australian continent. https://austhrutime.com/food_preparation_poison.htm