Flours from popped grains: Physicochemical, thermal, rheological, and techno-functional properties

Abstract

The popping of grains has been mainly used to produce ready-to-eat snacks. However, the popping effect on techno-functional properties and possible industrial applications is still unknown. This work evaluated the physicochemical, thermal, rheological, and techno-functional properties of flours from popped grains (FPG). White sorghum and corn grains were adjusted to initial moisture of 11 and 15% and popped using hot-air (210 °C, 90s). The physicochemical, thermal, rheological, and techno-functional properties were assessed in raw and popped flours. Raw flours showed different physicochemical and techno-functional attributes. However, the popping process homogenized their characteristics, behaving similarly in both FPG. Thermal properties evidenced a complete starch gelatinization in FPG and increased their initial viscosity from 8.4 (raw) to 794 cP. SPG showed a constant viscosity under heating-cooling conditions. The techno-functional properties of FPG showed higher water absorption and solubility (134–160%) values than raw ones. The syneresis was reduced in gels from FPG, reaching less than 3.6% after 48 h of storage. Finally, the FPG gels showed a more elastic matrix with lower deformation and higher cohesion. The techno-functional properties of FPG suggest that they can be used as food additives to improve consistency and stability. • The popping process led to total starch gelatinization. • Popped flours (PF) were thermally stable, showing a constant viscosity. • PF increased its water and oil absorption capacity, reducing syneresis after 48 h of cold storage. • PF gel showed a more elastic, cohesive, and rigid matrix than the raw one. • PF can be used to improve the consistency, firmness, and springiness of a food matrix.