关键词: 黄藤材, 微生物变色, 显微观察, 化学成分分析, 变色菌接种

Abstract:

The new felled fresh cane of Daemonorops margaritae is attractive yellowish white or creamy, but often change color during the course of transportation, storage, processing and utilization. Through the chemical composition analysis, the scanning electron microscope observation and the stain-fungi inoculation test of normal cane, the causes and types of the rattan cane are discussed, which is important for further research in preventing and removing the cane discoloration. Results showed that: 1) The cane's yellow discoloration was mainly chemical discoloration or photodiscoloration. The cane's blue, dark-brown and red stains were mainly caused by fungi, since there were always much fungus mycelia in the vessel and basic parenchyma tissue cells of the stained canes. 2) Compared with the normal cane, the extractive contents in all items of the fungal stained cane were decreased, and the pH value, the content of moisture, pentosan, holocellulose and ash were all increased. The chemical compositions of the core had greater change than the cortex, which indicated that the stain-fungi had greater influence on the core than on the cortex. 3) Fifteen fungi species were mainly isolated from the stained canes. After being inoculated with these fungi respectively, weight loss of all the normal canes was a little, but changed color greatly. The discoloration of the inoculated cane was consistent with the color of the stained cane from which the inoculating fungi were separated. Considering the stain-fungal cultivating characteristics, the blue, dark-brown and red discolorations of D. margaritae cane were mainly resulted from the colors of the stain-fungal mycelia or the pigments secreted by the stain-fungi such as melanin.

Key words: Daemonorops margaritae, cane discoloration, SEM observation, chemical composition analysis, fungi inoculation