Effect of red bean protein isolate and salt levels on pork myofibrillar protein gels mediated by microbial transglutaminase

- The effect of the level of RBPI and salt on the gel functionality MP mediated by MTG was examined.
- MP gels mediated by MTG with increased levels of RBPI and salt concentrations showed high cooking yield and gel strength.
- Increased salt level increased the 2nd endothermic peak, disappeared MHC and RBPI bands, and compacted and less void structures.
- RBPI can be used as a meat and water binder in MP mediated by MTG optimizing gel functionality at salt level of 0.3 M salt or more.

The objective of this study was to investigate the effect of red bean protein isolate (RBPI) at 0, 1, and 2% and salt concentrations at 0.15, 0.30, and 0.45 M on myofibrillar protein (MP) gels mediated by microbial transglutaminase (MTG, 1%). Cooking yield and gel strength of MTG-mediated MP gels increased as RBPI and salt concentrations were increased. The second peak of differential scanning calorimetry increased with addition of RBPI. SDS-PAGE showed disappearance of myosin heavy chain and several RBPI bands became invisible with increased salt level. Microstructures showed that the gels were more compact and less void with increased salt concentrations or addition of RBPI. Based on these results, the protein gel functionality mediated by MTG with RBPI appeared to be optimized with salt concentrations at 0.30 M or more.