Macronutrient composition of Button Grass, Curly Mitchell Grass, Native Millet and Weeping Grass grains for their potential in modern food applications

Abstract

Grains of Australian native grasses have been important components of traditional Aboriginal diets for millennia and have the potential for increased utilisation in contemporary food systems. This study assessed the macronutrient profiles of whole grains from Dactyloctenium radulans (Button Grass), Astrebla lappacea (Curly Mitchell Grass), Panicum decompositum (Native Millet), and Microlaena stipoides (Weeping Grass) compared to wheat, barley, and sorghum using proximate analysis, Osborne protein fractionation, gel electrophoresis, and carbohydrate assays. Key results were that Native Millet had high lipid content (8.0 g/100 g dry weight basis (db)), Curly Mitchell Grass had high protein (29.1 g/100 g db) and low carbohydrate content (64.0 g/100 g db), and there were substantial differences in prolamin and glutelin fractions across the species. All four native grains were gluten-free, and their starch amylose content ranged from 25.7% (Button Grass) to 41.2% (Curly Mitchell Grass), which affects starch properties. Button Grass had the highest dietary fibre content (21.9 g/100 g db), while Weeping Grass had the highest beta-glucan levels (8.6 g/100 g db), supporting functional food applications. Our findings highlight the potential for an expanded range of food applications for these grains and their contribution to human nutrition, together with implications for supporting Indigenous-led enterprises.