Synergistic effect of vitamin B1 on sanitizer and disinfectant treatments for reduction of coliforms in rice

The synergistic bactericidal effect of vitamin B1 (thiamin dilauryl sulfate) and the efficacy of commercial sanitizers and disinfectants for minimization of the contamination of total mesophilic bacteria and coliforms in rice were investigated. Water-treated rice exhibited a 0.7 log10 CFU/g reduction in both total mesophilic bacteria and coliforms. Reduction in sanitizer-treated rice was greater than for water-treated rice and reduction in sanitizer-treated rice with vitamin B1 was even greater than for sanitizer-treated rice. Coliforms in cooked rice after treatments with 5000 ppm hydrogen peroxide with 1000 ppm vitamin B1, 100 ppm chlorine with 800 ppm vitamin B1, 150 ppm chlorine with 500 ppm vitamin B1, 200 ppm chlorine with 100 ppm vitamin B1, and finally 100,000 ppm ethanol with 800 vitamin B1 were completely eliminated. The sensory properties of the above-mentioned sanitizer-treated cooked rice did not differ significantly from the same properties for water-treated cooked rice.