Evaluation of the Effects of Psyllium Husk on the Physicochemical Properties and In Vitro Protein Digestibility of Chicken Myofibrillar Proteins at Various NaCl Concentrations.

Reducing salt while maintaining meat product quality is important, and psyllium husk may help preserve quality and protein digestibility. This study was conducted to evaluate how the addition of psyllium husk powder (PHP) affects the rheological properties of chicken myofibrillar protein (MP) at various NaCl concentrations. Additionally, an in vitro digestion model was applied to evaluate the effects of PHP on protein digestibility. As NaCl increased, the viscosity of MP increased, and the addition of PHP further increased viscosity. The hydrophobicity increased with higher NaCl levels. However, the addition of PHP reduced the protein surface hydrophobicity within a given NaCl level. SH groups decreased while S-S groups increased as NaCl levels increased, and at a given NaCl level, the addition of PHP promoted the conversion of SH groups into S-S groups. Regardless of the NaCl level, adding PHP resulted in a stronger biopolymer band in the SDS-PAGE gel. The cooking yield and gel strength, which decreased with the NaCl level, were improved by the addition of PHP. In vitro digestion showed that PHP addition reduced protein digestibility in 0.15 M NaCl MP gels, had no effect at 0.30 M NaCl, and increased the digestibility at 0.45 M NaCl. Thus, the addition of PHP can improve the rheological properties of MP gels at lower NaCl levels, but may have different effects on protein digestibility depending on the NaCl level. PRACTICAL APPLICATIONS: These findings provide valuable insights for the meat processing industry, supporting the development of low-sodium meat products with improved digestibility, product quality, and overall product quality.