Proanthocyanidin B2 and transglutaminase synergistically improves gel properties of oxidized myofibrillar proteins.

We investigated the roles of Proanthocyanidin B2 (PCB2) and transglutaminase (TGase) in improving myofibrillar protein (MP) gel properties. TGase and PCB2 increased the surface hydrophobicity (41 %) and water holding capacity (WHC) (16 %) of the MP. Secondary and tertiary structures of MP were respectively analyzed by Fourier transform infrared spectroscopy (FTIR) and fluorescence spectrophotometry. The content of α -helix in MP was found to be increased while its fluorescence intensity decreased upon the addition of PCB2 and TGase. The addition of PCB2 and TGase resulted in formation of a dense MP network structure as revealed by scanning electron microscopy (SEM). Low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) analysis showed that immobilized water levels in the MP gel were markedly increased while the amount of free water was significantly decreased after PCB2 and TGase addition. These findings indicate that a combination of PCB2 and TGase are potential additives for meat products.