Evaluating the Dietary Safety of Australian Native Foods

As the native foods industry in Australia continues to grow, Indigenous Peoples of Australia are looking to become industry leaders. This has seen an emergence of traditional food items being developed for commercial markets. Even though many of these foods have a long history of use within various Indigenous communities, the evidence to suggest the safe use of these foods has rarely been recorded in written form. There has also been little research into the dietary safety of these foods. As such, supporting evidence to suggest these foods are safe for consumption within the general public is limited. Despite the extensive experience of Indigenous groups, the current regulatory framework used to assess the dietary safety of traditional foods does not have the capacity to recognise the unwritten (‘undocumented’) oral history held by the Indigenous population. This is presenting an unnecessary barrier that is prohibiting the recognition of the practical knowledge held by those groups who have been using native foods within Australia for at least 65,000 years. These knowledges extend not only to the practical skills around the harvest and preparation, but also the occurrence of adverse effects that may exist. These knowledge systems become particularly important to a risk assessment when you consider that many traditional plants also feature in traditional pharmacopoeias, and/or may be toxic at various growth stages or may require a detoxification step before consumption. In response to these shortcomings in current regulatory processes and the lack of supporting dietary safety evidence, the project outlined in this thesis was established as a joint collaboration between RMIT University and Food Standards Australia New Zealand (FSANZ). The overarching aim of the project was to establish a new methodological approach to the safety assessment of traditionally used native foods that would satisfy both industry and food safety regulators. This culminated in the proposed redevelopment of the current safety assessment framework and the establishment of safety assessment processes that are both accessible to small businesses entering the native foods market and appropriate for food safety regulators tasked with maintaining consumer safety. Chapter 1 of this thesis provides an extensive literature review of the current native foods industry within Australia, including the involvement of Indigenous Peoples within the industry and the current policy that dictates the regulation of native foods both within Australia and abroad. Risks and toxic effects that can be associated with the consumption of plant-derived foods are also highlighted, as are several methodological approaches used to assess the dietary safety of newly developed food items. This information provided adequate justification to pursue each of the research aims presented in the following chapters of this thesis. Chapter 2 addresses the first research aim by providing potential solutions to the shortcomings in the current regulatory procedures, including new proposed processes that can be incorporated into the current food regulatory frameworks to better assess the dietary safety of traditional foods. Importantly, these proposed processes would allow the dietary risk assessment of traditional foods to be completed in a manner that better accommodates the knowledge systems and interests of Indigenous Peoples, while also meeting the safety data requirements set out by regulatory bodies both within Australia and around the world. The second and third research aims are addressed in Chapter 3, where a dietary safety assessment is performed on a traditionally used native grain. This particular grain species was chosen because it is being developed by Aboriginal groups but lacked adequate supporting evidence to satisfy food safety regulations. The dietary safety of the grain has been systemically analysed and compared side-by-side with commonly consumed wheat in a range of in vitro bioassays and chemical analyses. In this study, native grain extracts were shown to be no more toxic than wheat in human monocyte and hepatocyte screening systems. Chemical analysis showed that contaminant levels were below tolerable limits, and no chemical classes of concern were identified. These findings indicate that this native grain species is no less safe than commonly consumed wheat. To further strengthen this assessment, and as proposed in Chapter 2, it is intended that the long history of use held by the Traditional Custodians who have used this grain for millennia is also considered in the overall dietary risk assessment. Chapter 4 addresses the fourth research aim, to further build upon the evidence base of the selected native grain by understanding its nutritional and functional properties. Compared with wheat, the native grain species contained 2-fold greater protein and total fats, and higher levels of essential minerals and trace elements, including 8-fold iron levels and >2.5-fold calcium, magnesium, zinc, copper and manganese levels. Functionally, the native grain contained 2.4-fold greater polyphenol content and displayed greater antioxidant potential in vitro in exposed human monocyte cultures. Importantly, the native grain was also found to be gluten-free. Altogether, this shows that the native grain is nutritionally and functionally superior to commonly consumed wheat for the measured parameters and could potentially serve as a grain alternative or be used to fortify current wheat-based and gluten-free products. These findings provide reassurance that the selected native grain is a viable product for further commercial development. It is hoped that the ideas presented in Chapter 2 of this thesis will provide some guidance on how FSANZ may be able to incorporate culturally appropriate processes into the regulation of traditional foods within Australia. The experimental results presented in Chapters 3 and 4 should facilitate safe market access for the native grain, whilst also providing a greater understanding of the nutritional and marketable attributes. Lastly, the methodology presented throughout should provide some guidance and clarity on how to successfully assess the dietary safety of traditionally used native foods, so that moving forward, a larger range of traditional foods can be safely developed for the market.