Shrinkage of cane (Arundo donax L.) II Effect of drying condition on the intensity of cell collapse

TL;DR

This study investigates how drying conditions affect cell collapse in Arundo donax L. canes, finding that faster, lower-temperature drying reduces collapse by limiting cell wall softening and viscoelastic yields during drying.

Contribution

It provides new insights into optimizing drying methods to minimize cell collapse in cane, highlighting the effects of drying rate, temperature, and surface conditions.

Findings

Faster, lower-temperature drying reduces cell collapse.

Slower drying increases collapse due to higher early-stage temperatures.

Surface conditions like waxy outer surface and nodes influence collapse intensity.

Abstract

To improve the drying method in the manufacture of woodwind reeds, green canes (Arundo donax L.) were dried under various humidity-temperature conditions and the intensity of cell collapse was evaluated from the swelling due to steaming involving the recovery of collapse. At 30 C, the intensity of collapse was increased by slower drying. It was considered that: 1) slower drying resulted in higher sample temperature in the early stage of drying to increase the collapse; 2) rapid drying stiffened the surface of sample and such "shell" prohibited the following collapse; 3) slower drying i.e. longer loading of liquid tension caused more remarkable and/or frequent viscoelastic yields of cells. Consequently the intensity of collapse increased when the cane was dried from its waxy outer surface or in the presence of node: both of them retarded the drying. On the other hand, higher drying temperature caused greater intensity of collapse in spite of faster drying. It was suggested that the thermal softening of cane cells leads to easier yield of the cell wall, at the same time the rapid drying does not allow the recovery of collapse after the disappearance of free water. These results indicated that faster drying at lower temperature is preferable for drying cane with less collapse.