Texture–acoustic, structural, and functional analysis of whole soy flour–corn extruded snacks under alkaline treatment

The main objective of this research is feasibility of producing protein snacks and evaluate its texture from Whole Soy Flour at extrusion processing by modifying the protein structure of soybean through pH adjustment. Optimization extrusion parameters (Temperature -feed rate Moisture - screw rotation speed) optained by previous research were utilized and acoustic analysis, a new sound-texture correlation method, was used to evaluate the quality of the snacks. To this purpose, WSF was added to corn flour in levels (0%, 25%, 35% w/w) and formulated and extruded at pH (7-12). WAI and OAI reduced significantly with rising WSF at pH 7, but pH raised WAI with progressing protein breakdown overall. WSI neared saturation at 25% WSF and showed a nonlinear pH pattern with alkalinity greatly reducing solubility. WSF addition substantially improved snack hardness. pH exerted a nonlinear and complicated effect on hardness. Acoustic analysis showed that WSF reduced the acoustic amplitude and produced a denser and softer texture, as confirmed by mechanical hardness measurements. Higher pH altered the acoustic spectra, where pH 10 softer textures and pH 11 produced longer acoustic peaks. Microstructural analysis proved that 25% WSF made the cell walls thicker, while 35% WSF caused higher heterogeneity. Color parameters, particle size, and zeta potential were all affected considerably by WSF and pH and also had a relationship with variations in pigmentation, protein aggregation, and surface charge density. The results can provide a scientific foundation for the modification of WSF-based food products in alkaline pHs.