Synergism of combined vitamin b₁ and naocl treatment for the reduction of microbiological contamination in head lettuce

The synergistic bactericidal effect of vitamin B₁ and sodium hypochlorite (NaOCl) on total aerobic bacteria (APC) and Escherichia coli contaminating head lettuce (Lactuca sativa) was evaluated. The concentrations of NaOCl and vitamin B₁ were varied from 50-200mg/L and 100-2,000mg/L, respectively. The reduction in APC and E. coli in head lettuce after treatment with NaOCl was 1.37-2.63 and 0.65-2.18 log₁₀ cfu/g, respectively. APC were reduced by 2.63 log cfu/g when NaOCl was used at a concentration of 200mg/L and by 4.90 log cfu/g when used in combination with 2,000mg/L vitamin B₁. Treatment with 200mg/L NaOCl resulted in a 2.18 log₁₀ cfu/g reduction in E. coli, while a reduction of 3.47 log₁₀ cfu/g was obtained when the sample was treated with 200mg/L NaOCl and 2,000mg/L vitamin B₁. These results suggest that a significant synergistic benefit results from combined NaOCl and vitamin B₁ treatments.