Starch is a major part of our diet. Food processing determines the physicochemical properties of starch in processed foods. An understanding of such properties is important in the development of strategies tomodulatedesirable textural attributes as well as the digestibility of starch in foods such as baked and extruded products. This review summarises the molecular interactions that occur during gelatinization and retrogradation of starch molecules studied using starch-water systems focusing on those with starch concentrations of 60-150% db relevant to baked and extruded foods. Little information exists on effects of starch concentration on digestibility and polymer conformations and structures of processed starch in concentrated systems.