Antioxidant activities, structure, physicochemical properties and in vitro digestibility of different millets (foxtail and proso)

In this study, the antioxidant activities, structure, physicochemical properties and digestibility of different foxtail and proso millets were investigated. Dark-coloured millets had lower lightness (L*) and higher total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activities than light-coloured millets. The polygonal and spherical starch granules of millet were wrapped and attached by proteins, lipids, etc. The X-ray diffraction patterns of millet flours exhibited A-type, with crystallinity of 34.64%-40.98% for foxtail millets and 31.72%-40.16% for proso millets. Compared with waxy millets, non-waxy millets were more resistant to swelling, gelatinisation and digestion, but showed a higher rate of retrogradation. Millet varieties with higher amylose content or higher TPC and TFC showed lower digestibility. These results will help to reveal the differences among millets with different types, varieties, colours and amylose content and provide theoretical guidance for their development and application.