Process history of calcium caseinate affects fibre formation

The Potential of Soluble Proteins in High-Moisture Soy Protein-Gluten Extrudates Preparation

In this study, the effects of different soluble proteins, including collagen peptides (CP), soy protein hydrolysate (HSPI), whey protein isolate (WPI), sodium caseinate (SC), and egg white protein (EWP), on the structural and mechanical properties of blends containing soy protein isolate (SPI) and wheat gluten (WG) were investigated using high-moisture extrusion. The addition of CP and HSPI resulted in a more pronounced fibrous structure with increased voids, attributing to their plasticizing effect that enhanced polymer chain mobility and reduced viscosity. WPI, SC, and EWP acted as crosslinking agents, causing early crosslink formation and decreased polymer chain mobility. These structural variations directly influenced the tensile properties of the extrudates, with CP displaying the highest anisotropic index. Moreover, the presence of soluble proteins impacts the permeability of the extrudates. These insights shed light on how soluble proteins can be used to modify the properties of SPI-WG blends, making them suitable for meat analogue production.

Effects of Process Parameters on the Fibrous Structure and Textural Properties of Calcium Caseinate Extrudates

Textured calcium caseinate extrudates are considered promising candidates in producing fish substitutes. This study aimed to evaluate how the moisture content, extrusion temperature, screw speed, and cooling die unit temperature of the high-moisture extrusion process affect the structural and textural properties of calcium caseinate extrudates. With an increase in moisture content from 60% to 70%, there was a decrease in the cutting strength, hardness, and chewiness of the extrudate. Meanwhile, the fibrous degree increased considerably from 1.02 to 1.64. The hardness, springiness, and chewiness showed a downward trend with the rise in extrusion temperature from 50 °C to 90 °C, which contributed to the reduction in air bubbles in the extrudate. Screw speed showed a minor effect on fibrous structure and textural properties. A low temperature (30 °C) in all cooling die units led to damaged structure without mechanical anisotropy, which resulted from fast solidification. These results show that the fibrous structure and textural properties of calcium caseinate extrudates can be effectively manipulated by adjusting the moisture content, extrusion temperature, and cooling die unit temperature.