Survival of Salmonella montevideo on Wheat Stored at Constant Relative Humidity

摘要

Eleven samples of Ottawa variety hard red winter wheat were inoculated with a standardized suspension of Salmonella montevideo. The contaminated wheat samples were placed in constant relative humidity (RH) chambers held at 25 C. Relative humidities were 7, 11, 22, 33, 43, 53, 62, 75, 84, 92, and 98%. Constant RH at 25 C was maintained with different saturated salt solutions in the sealed chambers. Periodic counts of viable S. montevideo cells per gram of wheat were made over a 28-week sampling period. Viable counts of S. montevideo on wheat held at 7, 11, and 22% RH decreased from an initial 106 cells/g of wheat to a final count of 104 cells/g in each sample. Samples stored at 33, 43, 53, and 62% RH decreased from 106 viable cells/g to 3.6 × 103, 103, 102, and 20 viable cells/g, respectively. No viable S. montevideo cells were detected in the samples held at 75, 84, 92, and 98% RH after 22, 16, 26, and 16 weeks, respectively.