Emulsion gels based on soy protein-pectin complexes as fat replacers: Enhancing pork sausage quality through...

Fat substitutes require materials capable of mimicking the functionality of animal fat while reducing caloric content. This study utilized soy protein isolate (SPI) and high-methoxyl pectin (HMP) to prepare composite emulsion gels as fat substitutes, replacing 25 % to 100 % of pork back fat in sausages. Results showed that all emulsion gels formed a stable three-dimensional network structure (G' > G″), at the molecular level, HMP forms strong and stable complexes with the protein surface. This binding mode helps to improve the stability of the emulsion gel system, which contributes to enhanced processing characteristics and sensory properties of fat-reduced sausages. The 25 % fat replacement exhibited textural attributes most similar to the control, with hardness decreasing from 15.96 N to 11.02 N and chewiness from 11.76 N to 7.99 N. Microstructural analysis revealed a more compact structure in these samples, supporting superior textural quality with overall sensory acceptability comparable to sausages made with pork back fat. In the in vitro digestion experiment, the fat-replaced samples were more easily digested, with the free protein content increasing to 5.73 mg/mL. These findings suggest that SPI-HMP composite emulsion gels effectively address the technical challenges of fat replacement, providing a promising strategy for producing healthier meat products.