The effect of gamma radiation was studied on yeast survival in sugar-cane molasses. Molasses (65o Brix) was diluted to 11o Brix and inoculated with Saccharomyces cerevisiae (strain M-300-A) yeast. The samples were irradiated with doses of 1.0; 2.0; 3.0; 4.0, 5.0 and 6.0 kGy (Cobalt-60), at a 1.703 kGy/h rate. The samples were stored at 4, 18 and 32oC during 7 and 14 day periods. No unit-forming colony was detected at the doses of 5.0 and 6.0 kGy, immediately after irradiation. Gamma radiation was effective to control yeast proliferation on sugar-cane molasses right after irradiation. The samples stored at 4oC for periods of 7 and 14 day did not show yeast proliferation, however none of the radiation doses was effective in controlling yeast proliferation of samples stored at 18 and 32oC for periods of 7 and 14 days. The D10 (dose for ten-times population reduction) determined for the yeast Saccharomyces cerevisiae in sugar-cane molasses, was 0.775 kGy.
Saccharomyces cerevisiae; irradiation; sugar-cane molasses; Saccharomyces cerevisiae; survival