Influence of malted buckwheat, foxtail and proso millet flour incorporation on the physicochemical, protein digestibility and antioxidant properties of gluten-free rice cookies

The gluten-free cookies with improved nutritional value and health promoting qualities were prepared by substituting rice flour with malted buckwheat (BW), foxtail millet (FM) and proso millet (PM) flours at 15 % and 30 % levels. The characteristics of malted BW, FM and PM flours obtained after germination for 1–4 days (GD = 1–4) were first evaluated. The increment in germination days caused a significant improvement in protein content, total dietary fibre (TDF), oil absorption capacity, amylase and protease activity of malted BW, FM and PM flours. Incorporation of 30 % malted (GD=3 and 4) BW, FM and PM flours increased the G', G'' and tan δ values of the cookies dough. The protein, ash, fat, TDF content and in vitro protein digestibility (IVPD) of cookies increased while glycaemic and starch hydrolysis index decreased by incorporating malted flours of all three grains. The incorporation of 30 % malted BW flour (GD = 3) increased IVPD, antioxidant capacity, protein, phenolics and flavonoids while incorporation of 30 % malted FM flour (GD = 4) proved useful in improving dietary fibres in gluten-free rice cookies. The 30 % malted BW and FM flour (GD = 3) can be incorporated in rice cookies for the improvement of nutritional and functional properties.