Pregelatinised amaranth flour as an ingredient for low-fat gluten-free cakes.

This work explored the use of pregelatinised amaranth flour (PAF) as an oil substitute in the preparation of amaranth cakes. Amaranth flour was extruded to achieve approximately 50% gelatinisation, ground and sieved. The PAF was used to replace the oil in the cake preparation at levels 33,66% and 100%. FTIR analysis of the cake formulations showed that PAF modified the molecular organisation of starch and proteins. The starch showed more hydrated structures, although less ordered. The proteins exhibited a significant reduction in the β structures and a marked increase of the side chains, probably caused by the interaction with amaranth starch. The in vitro digestibility of starch showed a slight increase with the addition of PAF. The slowly digesting starch fraction showed a visible decrease, reflecting the presence of starch chains more accessible to amylolysis. Instrumental texture revealed an increase (P<0.05) in cake hardness with the addition of...