Application of a new method to control microbial quality of foods based on the detection of oxygen consumption

New analytical techniques, the GreenLight™ system for rapid enumeration of total viable counts (TVC) were used to estimate the numbers of bacteria inoculated in different levels in broth nutrient media. The new detection methodology was compared with agar plating EN ISO 4833:2003 method showing excellent correlation. The following coefficients of determination R² = 0.985 and 0.999 were calculated for aerobic Pseudomonas aeruginosa and facultative anaerobic E. coli, respectively. After calibration, the system based on the principle of quenching of luminescence intensity and lifetime of an oxygen-sensitive dye by sample O₂ consumed during microbial growth enables to determine the number of microorganisms within less than 24 hours. The higher microbial load the shorter time for determination of viable count is needed. In case of simple food matrix for example, the results can be reached even within one shift of production.