Abstract: This study investigated the influences of curdlan (0.3%) and water addition (20%, 23%, 26% or 29%) on the quality characteristics of frankfurters. Cooking loss, emulsion stability, color, texture profiles, rhelogical properties, microscopic structure and sensory evaluation were measured. The mobility of water molecules in sausages was measured by low field nuclear magnetic resonance (LF-NMR). The results showed that for the control group without curdlan added, cooking loss and L* value significantly increased (P < 0.05), and emulsion stability, hardness, and overall acceptability decreased significantly (P < 0.05) with increasing water addition. However, for each addition level of water, frankfurters containing curdlan showed significantly lower cooking loss and significantly improved emulsion stability, hardness, springiness and overall acceptability than those without curdlan (P < 0.05). LF-NMR analysis showed that curdlan could decrease remarkably the relaxation time of water protons and increased the water binding capacity of frankfurters with higher amounts of water added. In addition, rheological analysis revealed that for each addition level of water, the addition of curdlan significantly increased the storage modulus (G’) and loss modulus (G”) were and decreased the phase angle tangent (tanδ) of meat batter at the end of heating, indicating that curdlan could improve the viscoelasticity of meat gels. At the same time, scanning electron microscope showed that higher levels of water addition loosened the structure of protein gels, while the addition of curdlan could improve the network structure of protein gels remarkably. The above results showed that although excessive addition of water would lead to deterioration in the quality of frankfurters, the addition of curdlan could reverse this deterioration. These findings can provide a theoretical basis for the application of curdlan in emulsified meat products.

Key words: frankfurter, curdlan, water addition, rheological properties, microstructure