Microbiological contamination in peanut confectionery processing plants

J Appl Microbiol. 2016 Oct;121(4):1071-8. doi: 10.1111/jam.13235. Epub 2016 Aug 28.

Abstract

Aims: In order to investigate Enterobacteriaceae, coliforms, Escherichia coli and Salmonella contamination, a survey was conducted at three peanut confectionery processing companies (A, B and C) in Brazil.

Methods and results: Samples of different peanut confectionery products (n = 59), peanut raw material (n = 30), manufacturing environment (n = 116) and workers' hand surfaces (n = 12) were analysed. Salmonella and E. coli were not detected in any final product or raw material analysed. Enterobacteriaceae was isolated from 15% of final products. Coliforms were detected in only one sample. Referring to the raw material, six samples showed contamination by Enterobacteriaceae and three samples by coliforms. For the process environment, 19% and 11% of samples presented Enterobacteriaceae and coliforms. Escherichia coli was detected in 5% of samples, and one of these samples tested positive for Salmonella; this strain was serotyping as S. Heidelberg. All food handlers surveyed in Company C showed Enterobacteriaceae and coliforms on their hands. Escherichia coli was isolated from one food worker's hand.

Conclusion: The results showed that the manufacturing environment, including food handlers were considered the main sources for possible contamination of peanut confectionery products.

Significance and impact of the study: This has been the first study to investigate the occurrence of Salmonella and other Enterobacteriaceae throughout peanut confectionery processing lines. The results might be used to assist risk assessment studies and to establish more effective control measures.

Keywords: Escherichia coli; Salmonella; food safety; food surveillance; peanuts; risk assessment.

MeSH terms

  • Arachis / microbiology*
  • Brazil
  • Colony Count, Microbial
  • Enterobacteriaceae / classification
  • Enterobacteriaceae / growth & development
  • Enterobacteriaceae / isolation & purification*
  • Food Contamination / analysis*
  • Food Handling
  • Food Microbiology
  • Humans