Abstract: Nuts, grains, seeds and other dry or dried foodstuffs are disinfected by a process that entails infusion with gaseous ozone and treatment with liquid non-ozone disinfectant, each treatment being preceded by a decompression of the foodstuffs to a pressure below atmospheric and each treatment utilizing an inert gas to achieve the exposure to the treatment agents at a pressure above atmospheric. The process achieves control of infestations at substantially all stages of the life cycle of pests, bacteria, and mold byproducts with which the product may be infested, and can do so in less than an hour.