Dose requirements for microbial decontamination of botanical materials by irradiation

• Published in: Radiation physics and chemistry (Oxford, England : 1993) England : 1993), 2002-03, Vol.63 (3), p.697-701
• Main Authors: Ražem, Dušan, Katušin-Ražem, Branka
• Format: Article
• Language: English
• Subjects: Botanicals; Herbs; Irradiation decontamination; Microbial contamination; Radiosensitivity
• ISSN: 0969-806X; 1879-0895
• DOI: 10.1016/S0969-806X(01)00604-1

Microbial contamination levels and corresponding resistivities to irradiation (expressed as dose required for the first 90% reduction, D first 90% red) were analyzed in a number of various botanical materials. The following generalizations could be made: total aerobic plate count is the most informative measure of contamination; the probability of contamination depends on available surface of the material and processing history: flowers and leaves usually contain more contamination than fruits and seeds, while crude herbs contain more than extracts; liquid extracts are more contaminated than dry ones. At the same time, resistivity to irradiation increases approximately in the reverse order of contamination level on going from flowers and leaves, to fruits and seeds, to liquid and dry extracts. The two quantities, probability of contamination and D first 90% red being inversely related, the treatment dose needed to reduce initial contamination to tolerable level amounts to between 4 and 30 kGy under a typical scenario, and between 8 and 40 kGy under the worst-case scenario for the whole range of raw materials and botanical products.