Application of pGFPuv mutant to study Cronobacter sakazakii survival in corn flour during storage

Abstract

Cronobacter sakazakii is more resistant in dry conditions for more than 2 years. However, study on the behavior of C. sakazakii in dry product using wild type may encounter problem of inability to distinguish target C. sakazakii with naturally occuring C. sakazakii. This research is useful in studying of C.sakazakii pFGPuv in corn flour having different initial moisture content stored in different relative humidity to ensure food safety and sustainability. The corn flour had a water content of 9% and 12 (w.b.) which had been inoculated with C. sakazakii pFGPuv for 16 weeks at 3 different RHs (50%, 70%, and 90%). The survival ability of C. sakazakii of GFPuv was better in corn flour with an Aw of 0.42-0.44 stored at RH 50% compared to RH 70 and 90%. C. sakazakii pGFPuv survived better at RH 50% which had Aw of 0.42-0.44 which was stored at RH 50% compared to RH 70 and 90%. The number of C. sakazakii pGFPuv in corn flour decreased by 0.470-0.489 log cycle/week. Therefore, the number of C. sakazakii in corn flour that will be stored needs to be considered to produce food that is safe to support good health and well-being.