Rheological properties of polysaccharides from Pholiota nameko with different temperature extraction: Concentration, pH, temperature, and saltion

Cold and hot water extracted polysaccharides (CW‐PNPs and HW‐PNPs) were isolated from Pholiota nameko. The rheological properties of PNPs were investigated by steady shear and oscillatory rheological measurements. The PNPs exhibited typical non‐Newtonian and shear‐thinning behavior, which are affected by PNP concentration, temperature, pH value, salt ion, and concentration. Specifically, the apparent viscosity of the two PNPs solutions at concentration of 1% (w/w) was shown as HW‐PNPs > CW‐PNPs. The apparent viscosity of PNPs decreases under acidic and alkaline conditions and when the temperature rises; K+ and Na+ cause the apparent viscosity of CW‐PNPs to decrease, while Ca2+ and Al3+ are opposite. The addition of four different salt ions all caused the apparent viscosity of the HW‐PNPs to decrease. The results of dynamic rheological experiments show that G′ and G″ showed slightly frequency dependency with G′ exceeding G″ throughout the accessible range of frequency for CW‐PNPs and HW‐PNPs.