Microwave-vacuum drying of round bamboo: A study of the physical properties

Rapid and clean drying of round bamboo is a highly desired process in utilizing bamboo resources. Theproperties of dried round bamboo (Phyllostachys iridescens C.Y.Yao & S.Y.Chen), such as moisture content,color, shrinkage and cracking. under different microwave-vacuum drying conditions were investigated inthis study. The results showed that the drying rate of round bamboo increased with drying temperature,microwave power and vacuum level. The chromatic parameters gradually deepened as the drying tem-perature increased. The surface color changed from green to yellow after drying.The shrinkage of sam-ples increased proportionally with temperature, microwave power and vacuum level, and the shrinkagein the top section was greater than in the bottom one. The cracking ratio of round bamboo was low whenusing microwave-vacuum drying technology, demonstrating that this technology can largely avoid theoccurrence of cracking and obtain rapid drying of round bamboo.