A sensor-based system for rapid on-site testing of microbial contamination in meat samples and carcasses

Area of Science:

• Food Microbiology
• Analytical Chemistry
• Biosensors

Background:

• Conventional methods for determining total aerobic viable counts (TVC) in raw meat and on carcasses are time-consuming and laborious.
• There is a need for rapid, simple, affordable, and on-site testing methods for microbial quality and safety in the meat industry.

Purpose of the Study:

• To develop and validate an oxygen sensor-based method for rapid quantification of TVC in raw meat and cattle carcass swabs.
• To assess the sensitivity, analytical performance, and on-site applicability of the new method.

Main Methods:

• Utilized a phosphorescent oxygen (O₂) sensor in standard vials for sample analysis.
• Employed a block heater and handheld reader for hourly signal readings to determine signal threshold time (TT).
• Sample preparation aligned with the established ISO4833-1:2013 plate counting method.

Main Results:

• Developed analytical equations correlating TT values to TVC load: TVC [Log(CFU/cm²)] = 7.83-0.73*TT(h) for swabs and TVC [Log(CFU/g)] = 8.74-0.70*TT(h) for meat.
• Achieved good correlation with ISO methods (r=0.85 for swabs, r=0.83 for meat).
• Demonstrated a time to result of 1-10 hours, significantly faster than conventional methods (48-72 hours), with no dilutions required.

Conclusions:

• The oxygen sensor-based method is simple, fast, high-throughput, and automatable.
• This method offers a viable alternative to conventional TVC testing, improving microbial quality and safety assessment.
• The method is suitable for adoption by the meat industry and research laboratories for enhanced process control.