Why is it tested?
Because it is the one routine parameter that shows numerically that process hygiene has slipped, before a pathogen shows up.
The difference between a food safety criterion and a process hygiene criterion
The Turkish Food Codex Regulation on Microbiological Criteria defines its criteria in two separate annexes: food safety criteria and process hygiene criteria. That distinction determines how a result is read.
A food safety criterion says whether the product may be placed on the market — Salmonella or Listeria monocytogenes, for instance. A process hygiene criterion says whether the process is operating acceptably; exceeding it does not mean the product is dangerous, it means the process needs correcting.
Aerobic colony count belongs to the second group. A high count therefore does not mean “this food will poison someone”; it means “something changed on this line”.
Where do you look when the count rises?
An aerobic colony count is a symptom, not a conclusion. When it rises, the questions come in order: has the raw material changed, has the cold chain broken, has the cleaning and disinfection procedure loosened, or has the product waited between production and consumption?
The answer usually comes from surface sampling. If the count rises on a product and also on the surfaces of the same line, the problem is in the environment, not in the raw material.
Are “total aerobic” and “aerobic” the same thing?
Our catalogue has two separate rows with different reference methods: ISO 4833-1 is the pour plate technique, ISO 4833-2 the surface spread technique. Both enumerate microorganisms growing aerobically at 30 °C; which is used depends on the structure of the product and the laboratory’s choice of method.
Escherichia coli by MPN works on a different logic: instead of counting colonies, a “most probable number” is calculated statistically from the positive tubes in a dilution series. It is preferred where the organism is very sparse or the product structure makes colony counting difficult.
A single high result says little; the trend of results from the same point says a lot. Aerobic colony counting is valuable when it is done regularly and from the same points.
Sources
- [1] Turkish Food Codex Regulation on Microbiological Criteria (Official Gazette, 13 February 2025, No. 32812) — Resmî Gazete (retrieved 31 August 2026)
The medical and legal information in this article is taken from the sources listed above and is not diagnostic or treatment advice. Figures are reproduced as published in those sources.
