Effectiveness of electron beam irradiation for microbial decontamination of turmeric powder (Curcuma longa Linne) and analysis of curcuminoid degradation

摘要

The effectiveness of electron beam (EB) disinfection and sterilization technology when applied tornturmeric powder (Curcuma longa Linne) was investigated. The bacteria in turmeric powder werernsensitive to EB irradiation. From an initial turmeric aerobic bacterial count of 10~7 colony-formingrnunits per gram (cfu/g), a microbial contamination level of below 1.0×10~3 cfu/g was obtained atrnan absorbed dose of more than 7 kGy EB irradiation. EB irradiation at 10 kGy gave a contaminationrnlevel of less than 10 cfu/g after 1 year of storage at room temperature. At the irradiation levelrnnecessary for decontamination of turmeric powder, the amount of dilute ethanol-soluble extractrnfrom the sample was 9% greater than the level from a non-irradiated turmeric powder. HPLC analysisrnof an irradiated sample indicated that EB radiolysis of curcuminoids was less than the levelrndetectable by instrumental analysis.