Transforming the inedible to the edible: An analysis of the nutritional returns from Aboriginal nut processing in Queensland's Wet Tropics

In ethnohistorical records, tree nuts are frequently referred to as important food sources for Aboriginal people in the tropical rainforest region of northeast Queensland. Experimental processing and chemical analyses were undertaken of nuts from yellow walnut (Beilschmiedia bancroftii), black walnut (Endiandra palmerstonii), black pine nut (Sundacarpus amara) and black bean (Castanospermum australe). Their energy values and potential dietary benefits were analysed through replication experiments that followed traditional Aboriginal processing techniques. Results indicate these species were all high energy-high return food sources. We propose that, despite the relatively intense preparation required, they would have provided an important and reliable source of starchy food within a varied rainforest diet. Findings support the proposal that processed toxic and noxious rainforest nuts may have played a significant role in the late Holocene permanent settlement of the rainforest region and in the development of a unique Aboriginal rainforest culture.