The protein fraction of slaughterhouse blood remains underutilized primarily due to challenges associated with its instability during processing and storage. This study aimed to develop stable bovine blood plasma gels using selected lactic acid bacteria and flaxseed oil cake flour. Various lactic acid bacteria strains were incorporated at concentrations of 5–20% (w/w), and gel properties such as pH, gelation time, yield stress, and freeze–thaw syneresis were evaluated. Optimal gelation was achieved at 20% inoculum, producing fibrin networks with yield stresses (372 Pa) comparable to recalcified controls (410 Pa), but accompanied by high serum loss and undesired acidic aromas at higher bacterial densities. Incorporating 5% hydrated flaxseed oil cake flour successfully reduced syneresis below 10%, improved water-holding capacity (135%), and prevented development of off-flavors, demonstrating beneficial interactions between flaxseed polysaccharides and blood plasma proteins. Thus, combining a 20% mixed lactic starter with 5% flaxseed cake flour yielded a stable plasma gel suitable for meat product applications, balancing rapid gel formation, high moisture retention, desirable rheological properties, and neutral sensory characteristics.

This study investigated the technological feasibility of using a pre-structured bovine blood plasma–flaxseed composition as a functional partial substitute for beef in emulsion-type sausages. Five formulations containing 0–30% replacement were evaluated to determine effects on structural, nutritional, and microbiological properties. Incorporation of the structured composition modified the functional balance of the protein system: water-holding capacity remained stable (p > 0.05), while fat-holding and emulsifying capacities improved at higher inclusion levels (p < 0.05), indicating enhanced interfacial stabilization of the fat phase. Progressive softening of texture was observed, with significant reductions in hardness and chewiness at 30% replacement (p < 0.05). Cooking loss increased at elevated substitution levels but remained within acceptable technological limits. During refrigerated storage, microbial counts remained below safety thresholds. A 15–25% replacement level provided the most balanced performance, maintaining sensory acceptability while improving lipid stabilization. The results demonstrate that structured plasma-based systems can function as effective protein–emulsion modifiers in meat formulations, supporting sustainable valorization of slaughter by-products.