Nonlinear rheological properties of Chinese cold skin noodle (liangpi) and wheat starch gels by large amplitude oscillatory shear (LAOS)

The recipe secret of making Chinese cuisine cold skin noodles (liangpi) with wheat flour was revealed by linear and nonlinear rheological characterization of wheat starch gel systems, which were made from different concentrations of liangpi slurry (LPS) and wheat starch slurry (WSS). The peak viscosity of LPS was suppressed at low concentrations and significantly higher than that of WSS at high concentrations. The G′ and G″ of LPS gels were higher than that of WSS gels under the same concentration, while the tanδ values were low in LPS gels and exhibited relatively greater mobility. This difference in LPS may be related to the non-starch components in it. The two starch gel systems were further characterized by the large amplitude oscillatory shear (LAOS) test. Lissajous curves showed that LPS gels follow a highly different elastic and viscous evolution than WSS gels during large deformation cycles. This was also evidenced by more pronounced strain stiffening and shear thickening trends of LPS gels and the larger I3/I1 values. The introduction of non-starch components was responsible for the significant changes in the properties of starch gels, and the LAOS method helped us to better understand these differences.