Abstract:

The oligomerization of Lentinula edodes handle fiber was conducted through single-screw extrusion. Viscosity
method was used to measure the degree of polymerization (DP) and molecular weight (MW) of extruded products. By using
response surface methodology, the oligomerization efficiency of extrude Lentinula edodes handle fiber was investigated
as a function of extrusion temperature, raw material particle size and liquid to solid ratio. The results showed the best
oligomerization efficiency was achieved when the fiber powder with particle size 0.147 mm (100 mesh) was extruded at
162 ℃ with a liquid to solid ratio of 1.43:1. It turned out that the DP dropped from 1 278 to 202, and the MW from 207 054
to 32 742. Scanning electron microscopy (SEM) observation showed the loose and porous structure of the extruded material,
and the original molecular structure was not significantly damaged as indicated by infrared spectroscopy, but a small part of
hemicellulose was degraded. Water-holding capacity, oil-holding capacity and expansive force of oligomerized Lentinula
edodes handle fiber were improved obviously compared with the untreated samples.

Key words: Lentinula edodes handle, fiber, extrusion, oligomerization