The effects of soy protein isolate-based composite gels as pork back fat substitutes in low-fat emulsified sausage

This study developed a soy protein isolate (SPI)-based composite gel system, incorporating oxidized chitin nanowhiskers, konjac glucomannan, and corn oil, functionally mimics porcine back fat in emulsified sausages formulations. Through systematic evaluation of SPI-based composite gel substitution levels (0, 50, 75, and 100 %) on quality parameters, we demonstrated that this biomimetic system significantly enhanced moisture content, protein levels, pH, L* and a*, while reducing total fat, calories, cooking loss, and lipid oxidation. At the optimal 75 % substitution ratio, microstructural analyses revealed a compact and uniform gel network structure. Low-field nuclear magnetic resonance and magnetic resonance imaging evaluations confirmed an improved water-holding capacity and uniform water distribution. This optimal formulation demonstrated enhanced water-holding capacity (89.47 ± 2.34 %), reduced cooking losses (9.39 ± 0.69 %), and achieved superior sensory acceptance (82.2 ± 4.97). Therefore, the SPI-based composite gel functions as a viable nutritional fat substitute in the production of low-fat, high-quality emulsified sausages without compromising textural or sensory attributes. The study offers a promising way to reconcile health-conscious formulations with desirable organoleptic characteristics in the development of commercially viable healthier meat products.