Abstract:Objective: To improve the nutritional value of millet and increase the digestibility of starch, the effects of heat-moisture treatment and fermentation on the in vitro bioaccessibility of mineral elements, amino acids, antioxidants and starch digestibility in foxtail millet were investigated. Method: In this paper, the foxtail millet was treated by heat-moisture treatment and fermentation alone or in combination. The release of amino acids, minerals and total phenols in simulated gastrointestinal digestion process was determined by amino acid analyzer, ICP-OES and Folin-Ciocalteu method, respectively. Sarch digestibility was determined by in vitro enzymatic digestion protocol. The antioxidant activities of the treated samples were compared by ORAC method. Result: Heat-moisture treatment increased significantly the bioaccessibility of zinc and reduced the bioaccessibility of iron. The contents of slow digestion starch (SDS) and resistant starch (RS) were increased from 20.1% and 13.3% to 26.8% and 17.1%, respectively. Fermentation significantly reduced the in vitro digestibility of the protein, increased the bioaccessibility of the iron and zinc elements and the content of SDS. Heat-moisture treatment and subsequent fermentation increased the bioaccessibility of lysine and total amino acids by 74.4% and 41.5%, respectively. The RS content in dual treated foxtail millet was further increased compared with the heat-moisture treated samples. However, the bioaccessibility of iron was decreased. The content of free phenol was 19-22 times higher in simulated gastrointestinal tract than before digestion. The dual treated samples showed the highest antioxidant activity. Conclusion: In the processing of gluten-free foxtail millet food, the combination of heat-moisture treatment and fermentation is expected to be a promising technical means in improving the bioaccessibility of nutrients.