Optimizing protein bars with whey protein isolate, pea protein isolate, and blue whiting (Micromesistius poutassou) fish protein hydrolysate: A simplex-centroid mixture design study

The aim of this study was to use blue whiting fish protein hydrolysate (BWFPH) as a novel dietary amino acid supplement in whey protein isolate (WPI) and pea protein isolate (PPI)-based protein bars. The findings indicate that incorporating BWFPH significantly influenced the nutritional profile of the protein bars, leading to a ~93% reduction in hardness compared to bars without the hydrolysate. Additionally, BWFPH effectively delayed the hardening process during storage. However, sensory evaluation revealed that the inclusion of BWFPH adversely affected the sensory characteristics, indicating a need for optimization. Using a simplex centroid mixture design, we identified an optimized protein blend compromising 76.02% WPI, 6.72% PPI, and 17.26% BWPFH, which achieved a balance of improved texture and sensory appeal. These results suggest that high-protein bars can be enhanced by integrating novel protein sources through careful formulation and optimization.