A native Australian shrub, traditionally used as livestock feed and held in esteem by Indigenous Australians, is undergoing scientific evaluation as a potential high-protein food source for human consumption. Researchers at RMIT University in Melbourne have found that Old Man Saltbush (Atriplex nummularia) exhibits a protein quality comparable to, and in some cases exceeding, that of soy, pea, and rice proteins.
The research, published in the journal Food and Bioprocess Technology, details a comprehensive analysis of saltbush powder, examining its macronutrient composition, amino acid profile, and mineral content. PhD candidate Samiddhi Gunathilake, the study’s principal author, highlighted the plant’s potential to diversify protein sources and contribute to more sustainable food systems. The study is titled “Exploring the Physicochemical Properties of Saltbush (Atriplex nummularia) Powder as a Novel Sustainable Food Ingredient: Impact on Wheat Flour Noodle Quality.”
Beyond protein, Old Man Saltbush is rich in essential minerals including calcium, iron, phosphorus, zinc, and sodium, all vital for physiological functions. The analysis also revealed a comparatively higher fat content than conventional plant flours, which researchers believe could improve the texture and mouthfeel of food products. The plant’s natural green hue also offers aesthetic possibilities for culinary applications.
To demonstrate practical application, the RMIT team incorporated ground saltbush powder into wheat flour noodles. The resulting pasta exhibited a doubled protein concentration and an eightfold increase in dietary fiber compared to standard wheat pasta. According to the research, a single serving of the saltbush-enriched pasta provides nearly half the recommended daily protein intake for an adult.
Dr. Mahsa Majzoobi, the study’s lead investigator, emphasized the nutritional advantages of saltbush over wheat flour alone. She noted its potential as a natural salt substitute, which could contribute to reducing sodium intake in processed foods. Importantly, saltbush addresses a common deficiency in wheat-based diets – a lack of the essential amino acids lysine and tryptophan, providing a more complete protein profile when combined with wheat flour.
The researchers acknowledge that further investigation is needed to assess the long-term impacts of saltbush consumption on gut health and overall nutrition, as well as to gauge consumer acceptance. Scaling up production while maintaining supply chain consistency also presents a significant challenge. The team plans to collaborate with agricultural stakeholders to optimize farming practices for saltbush, capitalizing on its drought-tolerance to create a resilient and localized supply chain.
The research aligns with a broader effort to integrate climate-resilient native plants into food systems, promoting both dietary diversification and environmental sustainability. RMIT University’s work aims to transform Old Man Saltbush from a niche fodder crop into a valuable food ingredient, potentially offering a solution to global food security and nutrition challenges.
