Decontamination of Dry Food Ingredients and Seeds with “Soft-Electrons” (Low-Energy Electrons)

Electrons with energies of 300 keV or lower (soft-electrons) reduced microbial loads of grains, pulses, spices, dehydrated vegetables and seeds to levels lower than 10 CFU/g. The viscosity of gelatinized grain powder suspension (parameter for starch degradation) showed no significant difference between untreated grains and soft-electron treated ones, which indicated that soft-electrons did not significantly degrade the starch molecules of grains. Electrons with a higher energy with a higher penetration capacity resulted in a higher thiobarbituric acid value (TBA, parameter for lipid oxidation) of brown rice. Milling rice at a yield of 90% or 88% after electron treatment made the TBA of rice treated with electrons at 65 keV almost the same as that of untreated rice. The results indicated that the milling process removed the portion of brown rice exposed to soft-electrons. Seeds which were exposed to soft-electrons showed the same sprouting capacity as untreated seeds. Soft-electrons could eradicate microorganisms on the surface of dry food ingredients and seeds with little adverse effects on quality and sprouting capacity.