Inactivation kinetics for Salmonella typhimurium in red pepper powders treated by radio frequency heating

Sizhuo Hu, Yanyun Zhao, Zvi Hayouka, Danfeng Wang, Shunshan Jiao*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

46 Scopus citations


Radio frequency (RF) dielectric heating has been investigated to inactivate pathogens in some low-moisture foods. This study was aimed to evaluate RF inactivation effects on Salmonella typhimurium in red pepper powders, by focusing on the influence of sample initial water activity (aw) and applying Weibull model to describe the inactivation curves. The experimental results showed that RF heating rate increased when aw was in the range of 0.57–0.71, but decreased after aw reached to 0.71. During the come-up time of RF heating, 2–3 log reduction of the pathogen was achieved depending on aw levels. Increasing initial aw could first increased log reductions and then decreased the log reductions, optimum aw level was 0.71 for RF inactivation of Salmonella in red pepper powders. For red pepper powders with aw of 0.71, RF heating to 70 °C (come-up time was 110 s) with holding time over 60 s could achieve >5 log reduction of S. typhimurium. Weibull model well fitted the survival curves of the pathogen with goodness of fit (R2 > 0.93, RMSE<0.29). Scale factor (b) of the model increased with treatment temperature increasing, while the shape factor (n) was independent on temperature. This study provided basic guideline for using RF heating to inactivate Salmonella in red pepper powders.

Original languageAmerican English
Pages (from-to)437-442
Number of pages6
JournalFood Control
StatePublished - Mar 2018

Bibliographical note

Publisher Copyright:
© 2017 Elsevier Ltd


  • Radio frequency (RF)
  • Salmonella typhimurium
  • Water activity (a)
  • Weibull model


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