Phase-separation wet spinning for fabricating composite fibers with protein-polysaccharide multicrosslinked structures: From plant proteins to livestock meat

Meat analogs serve as a promising alternative to traditional meat consumption, addressing human health needs, promoting environmental sustainability, and tackling food security challenges. However, achieving parity in texture and flavor with traditional meat remains a critical area for enhancement. In this study, soy protein isolate (SPI) was employed as the primary protein source, while carrageenan (CG) and sodium alginate (SA) acted as carriers. A phase-separation wet spinning approach was used to construct SPI/SA/CG fibers with a robust hydrogen-bonded and ion-coordinated multicrosslinked network structure. The fibers were comprehensively analyzed for their textural attributes and digestive behavior. The SPI content increased the apparent viscosity of SPI/SA/CG solutions, enhanced their non-Newtonian behavior, raised the structural viscosity index, and reduced spinnability. The SPI/SA/CG fibers exhibited multiple hydrogen bonds and metal coordination interactions, with the type and strength of hydrogen bonding dependent on SPI content. SPI was predominantly present in β-sheet and β-turn conformations within the fibers. Within the operational temperature range of 40–78°C, SPI/SA/CG fibers displayed excellent thermal stability, experiencing minimal mass loss of just 4 %-6 %. The moisture content of SPI/SA/CG fibers closely matched that of livestock meat, with a maximum value of 79.51 %. Texture analysis confirmed that SPI/SA/CG fibers had a texture comparable to real beef, with the elasticity and cohesiveness of SPI_2.25/SA/CG fibers achieving a similarity of up to 94 % to beef. Further digestion analysis validated the efficient release and digestion of SPI/SA/CG fibers under simulated gastrointestinal conditions. This study offers a robust and innovative approach to advancing the development of meat analog fibers.