Application of flow cytometry to rapid microbial analysis in food and drinks industries

Abstract

In food and drinks industries, the time required for conventional tests can lead to substantial delays in product release to the market. Flow cytometry (FCM) has been used in conjunction with viability markers for rapid counting of yeast, mould and bacterial cells in food products. A single-parameter flow cytometer has proved applicable to the rapid detection of low numbers of microbial contaminants in finished products. The excellent correlation between FCM results and product quality shelf-life expiry date has allowed the establishment of realistic quality control criteria for rapid positive release of product. Used for the monitoring of microbial biomass during manufacturing processes, flow cytometry allowed a direct assessment of bacterial growth. The reproducibility of the results and the proven correlation with standard plate count method obtained in industrial conditions make FCM a good predictive method for product and process quality control.

Application of Flow Cytometry to Segregated Kinetic Modeling Based on the Physiological States of Microorganisms

“…Obviously, higher growth rates do not suppose that cells divide more rapidly but in this case can be explained based on the different characteristics of each method. Laplace-Builhé et al (27) pointed out that significant differences could be obtained in the count of viable bacteria in the production of lactic starter cultures according to the enumeration method. As described above, the maximum cell concentrations were different depending on the technique used to determine total biomass, reaching higher values from FC analysis (16.8 g ⅐ liter Ϫ1 for yeast and 1.9 g ⅐ liter Ϫ1 for bacteria).…”

Improved detection of bacteria by flow cytometry using a combination of antibody and viability markers

“…Medical applications include bacterial responses to antibiotics (Gant et al 1993 ;Mason et al 1995), analysis of blood (Mansour et al 1985) and other clinical samples (Humphreys et al 1994 ;van der Waaij et al 1994). Interest in food analysis has centred around pathogenic bacteria and spoilage organisms (Donnelly and Baigent 1986 ;Patchett et al 1991 ;Laplace-Builhé et al 1993).…”

Development of a Flow Cytometric Method To Analyze Subpopulations of Bacteria in Probiotic Products and Dairy Starters

“…Also, FCM has been used for analysis of bacteria in environmental samples, such as soil, air, and especially water (31,32,37), and in clinical samples, such as blood, urine, and feces (1,31,36). The potential of FCM for the food industry has been recognized as well (19,32,35). Some applications have been developed for FCM analyses of food products, such as meat, fruit juices, eggs, and milk.…”