Evaluation of the Petrifilm SM® Spiral plating®, Pro·media MT-21® and Colilert® Methods for Bacterial Counting and Total Coliforms in Pickled Vegetables (Asazuke)

Abstract

The application of Petrifilm SM_®, Spiral plating®, Pro·media MT-21® and Colilert® methods for bacterial counting and total coliforms in pickled vegetables (Asazuke) were examined. Petrifilm SM®method, pour plate method and Spiral plating®R method were compared to determine standard plate counts of 127 pickled vegetable samples. Correlation coefficients of Petrifilm SM®R plate versus pour plate and Spiral®R plating method was 0.991 and 0.962, respectively. The replicate variances of these me thods were not significantly different at 5% level. Total coliforms of 137 pickled vegetable samples were determined by using brilliant green lactose bile broth (BGLB) tubes, Pro·media MT-21®R cups and Autoanalysis Colilert®R tubes. The results of these methods after incubation for 48±3h were closely coincided at the rate of 86.1-92.0%. Within 24±2h incubation, 89% of total coliforms could be detected by Pro·media MT-21®R method. The presence of E. coli was confirmed by fluorescence undera longwave (366nm) UV irradiation by Autoanalysis Colilert®R test.