A four serovar cocktail ofSalmonellawas inoculated into ground black pepper (Piper nigrum) at different
water activity (aw) levels at a starting level of 4e5 log cfu/g and incubated at 25 and at 35
C. At 35
C and
awof 0.98860.0006, the generation time in ground black pepper was 313 min with a lag time of
41 h. Growth at 25
C had a longer lag, but generation time was not statistically different from growth
at 35
C. Theawthreshold for growth was determined to be 0.9793 0.0027 at 35
C. To determine
survival during storage conditions, ground black pepper was inoculated at approximately 8 log cfu/g and
stored at 25 and 35
C at high (97% RH) and ambient (40% RH) humidity. At high relative humidity,aw
increased to approximately 0.8e0.9 after approximately 20 days at both temperatures and noSalmonella
was detected after 100 and 45 days at 25 and 35
C, respectively. Under ambient humidity, populations
showed an initial decrease of 3e4 log cfu/g, then remained stable for over 8 months at 25 and 35
C.
Results of this study indicateSalmonellacan readily grow at permissive awin ground black pepper
and may persist for an extended period of time under typical storage conditions.