Assessment of Performance of Two Rapid Methods for On-Site Control of Microbial and Biofilm Contamination

Fernando Lorenzo,Ramón Bertó,Enrique Orihuel,Maria Sanz-Puig

doi:10.3390/app10030744

Abstract

(1) Background: The validation of hygiene procedures in food industries is paramount to ensure that food contact surfaces are properly decontaminated before production. Rapid, sensitive and reliable tools are needed for routine hygiene validation in order to increase food safety levels. Two novel tools for biofilm detection (TBF 300) and detection of low levels of microbial contamination (FreshCheck) have been assessed. (2) Methods: Biofilms of relevant food pathogens: Listeria monocytogenes and Salmonella spp. were grown for 3 and 10 days to assess the performance of the biofilm detection product. Surfaces were inoculated with different levels of L. monocytogenes to determine the limit of detection of FreshCheck. (3) Results: TBF 300 visibly stained 3 days-old biofilms of both pathogens, containing 5.0–5.4 log CFU/cm2. FreshCheck showed a positive reaction with contamination levels as low as 10 CFU/cm2 for L. monocytogenes. (4) Conclusions: Assessment of the hygienic status of food contact surfaces before production can be greatly improved with the use of the two novel tools evaluated in this study. The detection of microorganisms’ presence at very low levels of contamination as well as identification of biofilm growth spots is available in a rapid and easy way, with a big potential contribution to food safety.

Highlights

In food production, the presence of unwanted microorganisms is a major risk for the quality and safety of the food products
These results show that can reliably reveal biofilm presence stainless steel surfaces
Two novel tools commercially available for validation of hygiene control in food industries have been evaluated. Both detection of microbial contamination at very low levels and industries have been evaluated. Both detection of microbial contamination at very low levels and identification of biofilm presence in a rapid and easy way are very significant for microbiological identification of biofilm presence in a rapid and easy way are very significant for microbiological control in food industries

Summary

Introduction

The presence of unwanted microorganisms is a major risk for the quality and safety of the food products. Improper hygiene can lead to remaining food residues on work surfaces and equipment [4] This has two detrimental effects: (i) partial inactivation of disinfectants used for decontamination of surfaces, resulting in limited decontamination and potential exposure of microorganisms to sublethal concentrations of biocide [5,6]; and (ii) presence of anchor points for the attachment of bacteria, favoring the growth of a biofilm. In both cases, the result is the occurrence of persistent contamination [7], comprised of microorganisms that resist conventional hygiene procedures, either because they have developed increased tolerance to

Methods

Results

Conclusion