The sporostatic effect of cannabidiolic acid

A study was undertaken to clarify whether cannabidiolic acid could be made to enhance the microbiological effect of food preservation by heat treatment or irradiation. Cannabidiolic acid was found to have a high inhibiting effect on the spores of Bacillus cereus. Its sporostatic effect is roughly equivalent to that of the antibiotics nisin and tylosin. The aqueous solution of the phytoncide of 50 μg ml-1 concentration (containing 2.5% alcohol) resisted, without a reduction of its activity, a heat treatment of 30 min at 110 deg C. Its activity was reduced by only 15% upon treatment with 400 krad. Hereafter the influence of cannabidiolic acid, added to the brine of canned peas at a concentration of 10 μgml-1, was studied on samples exposed to treatment with 500 krad or given a heat treatment equivalent to F0=4.8. In these combination treatments cannabidiolic acid added at the above concentration proved to be ineffective. On investigating the cause of this phenomenon, cannabidiolic acid was found to react with protein of peas prior to irradiation or heat treatment, or in an early phase of treatment loosing thereby its microbiological effect. On the other hand, since cannabidiolic acid cannot react with proteins denatured by heat, it was found active in a sterilized nutrient medium containing denatured protein. (F.J.)