Impact of moisture content on microstructural, thermal, and techno-functional characteristics of extruded whole-grain-based breakfast cereal enriched with Indian horse chestnut flour

•Breakfast cereals from whole grain flours were blended with Indian horse chestnut flour.•The breakfast cereals showed dense inner structures with closed air cells.•Increasing conditioning moisture increased bulk density, water absorption index and antioxidant activity.•Crystallinity of starch, expansion and water solubility index changed.•Crystalline structure rearranged from A- to V-type. The use of non-conventional seed flour is of interest in obtaining healthy breakfast cereals. The research aimed to study the physico-functional, bioactive, microstructure, and thermal characteristics of breakfast cereals using scanning electron microscopy, X-ray diffractometry, and differential scanning calorimeter. The increase in feed moisture content (16 %) enhanced the bulk density (5.24 g/mL), water absorption index (7.76 g/g), total phenolic content (9.03 mg GAE/g), and antioxidant activity (30.36 %) having desirable expansion rate (2.84 mm), water solubility index (48 %), and color attributes. The microstructure showed dense inner structures with closed air cells in extruded flours.Extrusion treatment rearranged the crystalline structure from A-type to V-type by disrupting the granular structure of starch, reducing its crystallinity, and promoting the formation of an amylose–lipid complex network. Increasing conditioning moisture enhanced the degree of gelatinization (%), peak gelatinization temperature (Tp), and starch crystallinity (%) and reduced the gelatinization enthalpy (ΔHG) and gelatinization temperature ranges. The results reported in this study will help industries to develop innovative and novel food products containing functional ingredients.