To some extent, high temperatures can effectively facilitate the
degradation of the fiber. Based on the results of our preliminary
experiments, a temperature of 170 C was selected for the extrusion
process. As depicted in Fig. 2a, the concentration of SDF increased
initially and reached a maximum yield of 20.38% at an
extrusion screw speed of 150 r/min. The increase in the extrusion
screw speed enabled samples to be subjected to sufficient heat
transfer and pressure. However, the concentration of SDF dropped
sharply when the extrusion screw speed was increased to 175 r/
min or 200 r/min. This decrease may be due to the Maillard reaction
and carbonization of SDF, which reduces the extraction ability
at higher screw speeds