title: Pilot-scale radio frequency pasteurisation of chili powder: heating uniformity and heating model.
abstract: BACKGROUND
  Microbial contamination is a vital obstacle needed to overcome for food safety of condiments. Radio frequency (RF) pasteurisation is a new technology to solve this obstacle. Temperature distribution and heating uniformity of sample, which are influenced by different factors, are the most important things affecting the nutritional ingredients and microbial safety of sample in the process of RF pasteurisation. This study demonstrated the location of cold spot in chili powder by analysing temperature distribution in horizontal and vertical direction. The related models were established and the accuracy was verified.
  
  
  RESULTS
  Cold spot located on the centre of sample surface in the process of RF pasteurisation. The averaged temperature of sample increased linearly. The uniformity index decreased as the averaged temperature increased. Both the correlation coefficient of two equations were greater than 0.91. The error value of heating rate and heating uniformity index was 0.54% and 0.75% between the measured value and predicted value.
  
  
  CONCLUSIONS
  Electric field was not uniformly distributed between RF parallel-plate electrodes in the RF pasteurisation of chili powder. The heating models were reliable to predict experiment results with high precision and accuracy. © 2015 Society of Chemical Industry.
authors.affiliation: College of Food Science & Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Yukun
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Food Science & Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Yongdi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Food Science & Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Lei
authors.affiliation: College of Food Science & Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Hongfei
authors.initials: H
authors.lastname: Fu
authors.affiliation: College of Food Science & Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Xiangwei
authors.initials: X
authors.lastname: Chen
authors.affiliation: College of Food Science & Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Yunyang
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000465:Algorithms; D002212:Capsicum / Q000737:chemistry* / Q000191:economics / Q000528:radiation effects; D002681:China; D004566:Electrodes; D005638:Fruit / Q000737:chemistry* / Q000382:microbiology / Q000528:radiation effects; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D007700:Kinetics; D008956:Models, Chemical; D009753:Nutritive Value; D061352:Pasteurization / Q000295:instrumentation / Q000379:methods*; D010865:Pilot Projects; D011846:Radio Waves / Q000009:adverse effects; D015203:Reproducibility of Results; D017365:Spices / Q000032:analysis* / Q000191:economics / Q000382:microbiology / Q000528:radiation effects; D013499:Surface Properties; D014867:Water / Q000032:analysis
chemical_list: D014867:Water
keywords: chili powder; heating model; heating uniformity; radio frequency pasteurisation