Determining the pore structure and radial variability of moso bamboo (Phyllostachys edulis)

The native pore structure and characteristic are the basis for studying the permeability, pretreatment and further processing of bamboo. Herein, the porosity, surface area, pore volume and pore size distribution of moso bamboo and their radial variabilities were investigated by a combination of mercury intrusion porosimetry (MIP), nitrogen adsorption and scanning electron microscopic image analysis. Bamboo has a wide porosity range (48 similar to 70%) that exhibits a quadratic polynomial relation to the radial position, and parenchyma tissue shows higher surface porosity (around 71%) compared to vascular bundles (50.5 similar to 20.3%). The cell wall pores uncovered by MIP and N-2 adsorption display the meso- to macropores abundant characteristics and the mesopores account for 54.5 similar to 62.4%. Different radial samples demonstrate the similar pore size distributions but variable volumes and surface areas (85.3 similar to 88.2 m(2)/g). The outer part of bamboo has these values smaller than that of middle and inner samples, revealing a more compact structure. The present work gives an in-depth view on bamboo pore structure and radial heterogeneity, which could provide the basis for pretreatment and subsequent development of value-added bamboo products.