The impact of spray-dried potato flour on the techno-functional, rheological and digestibility traits of white sorghum flour-based flatbreads

The purpose of this study was to develop innovative batter-based flatbreads from a composite flour containing two sources, namely sorghum flour (SF) and spray-dried potato flour (PF). Sorghum flour (S₁₀₀) was considered as the control, and was partially substituted with spray-dried potato flour at levels of 10% (S₉₀), 20% (S₈₀), 30% (S₇₀), 40% (S₆₀) and 50% (S₅₀), respectively. Proximate composition analysis revealed that substitution with PF caused an increase in carbohydrate and ash contents, whereas a proportional decline was observed in fiber and fat contents. Increasing levels of PF led to a significant reduction in maximum viscosity (MV) and hot paste viscosity (V95). The phase angle (δ) decreased with increased substitution, implying that the batters became more elastic. Regarding texture analysis, the maximum force (Fmax) required to tear apart the flatbread was observed to be the highest for S₈₀, i.e., 1.067 MPa, which decreased significantly for the S_70, S₆₀ and S₅₀ flatbread samples. Higher substitution levels of PF yielded softer flatbreads, owing to the pregelatinized nature of spray-dried PF. The in vitro digestibility of the flatbreads was found to be dependent on viscosity. The lowest glycemic index (pGI) was obtained for S80, i.e., 42.86, due to its maximum viscosity, i.e., 4.33 Pa.s. The flatbreads prepared from composite flours had lower L values (slight darker) in comparison to the control flour flatbread. The sensory profile of the composite flour-based flatbreads was insignificantly different from that of the control (S₁₀₀), and scored >4 on a hedonic scale of 5.