GMP-Microbiological control tests after sanitation process

The basis for sanitation is the removal of soils from the manufacturing environment. There are many benefits to this process. From a food safety standpoint, there is the removal of pathogenic organisms, prevention of the formation of biofilms and removal of potentially harmful chemicals from food contact surfaces. From a quality standpoint, there is removal of spoilage organisms to improve the shelf life of refrigerated or ambient product and decrease the opportunities for spoilage. Sanitation is also used to prevent cross-over of residue from different animal species as well as preventing flavor impact by cross-over of spices and flavorings. Improved sanitation performance can also increase productivity by facilitating efficient plant start-up.

This article is about the different microbiological controls should be used to ensure the food safety in the process of sanitation. This microbiological control step can be an Operational Pre-Requisite Program (PRP focussed on single process and continuous control and monitoring is not possible) to maintain Good Manufacturing Practices and food safety. We discussed what is an oPRP in our last article and it can be referred to know more about oPRP.

Microbiological contaminants of concern can depend on the type of product and the process through which the product passes. The primary pathogen of concern for sanitation, particularly in ready-to-eat meat and poultry operations, is L. monocytogenes as it is a ubiquitous organism, meaning it can be found frequently throughout the environment and can grow under a wide range of conditions in food plants. Salmonella and E. coli O157:H7 are not generally considered environmental contaminants; however, they are organisms that need to be removed from the environment. Contamination of food products with spoilage microorganisms that do not result in foodborne illness, however, may be the underlying cause for reduction in shelf life of food products. While these organisms is easily eliminated through cooking, they are responsible for spoilage of product in the ambient shelf or refrigerated state. Spoilage organisms include yeast, mold, Lactobacillus, Pseudomonas and rope spores. These are all removed by effective cleaning and sanitation. 

Experts' View on different microbiological tests and frequency of swabs:

José Eduardo Villavicencio C. who is a food safety specialist from Peru says "you should make a risk analisys first, consider process, area, equipments and workers all as a pre requisite system (GMP). 

If the product is in direct contact with manipulator start with the highest swab frecuency, It all depends in your personal training and discipline. Once you have enough data to validate it is controlled, you can reduce it. 

Generally, the microorganisms belongs to the coliform and yeast groups (hygiene indicators), these are mandatory to controll manipulators and equipments cleaning. 

Again, depending on risk analisys, you can fix what patogen m.o. to detect: E.coli, listeria monocitogenes, s. aureus with a lower frequency, maybe once a month, twice a year, etc. Not necessary to control all the time if your cleaning is OK.

For equipments there are solutions to control through indirect methods"

Kok Ying Lee, a food safety consultany from London has a different view on the same issue "Swab should be done after each production run, to ensure equipment etc., is "clean" and ready for next production batch. As for microbial checks, focus on indicator organisms and depending on product, select the pathogens commonly associated with the particular product."

Ken a scientist in Edinberg Scientific Services says "Having worked in both the food industry and food regulatory industry I can see both side of argument. As has been said you have to establish risk i.e. is it a high risk e.g. highly perishable product such as fresh meat, dairy etc. or is it a long life product? Having done that this dictates the frequency and type of any monitoring. I personally prefer Total viable bacterial count as the most important indicator and you will see the trends of cleaning this way. Other parameters are also important but less sensitive. I would include Enterobacteriaceae, and Staphylococcus where handling is an issue. Depending on product type and risk it may be advisable to include Yeasts and moulds as well. Pathogen testing tends no to be particularly effective and is a bit "hit or miss". In places where it is done it often produces a false sense of security as pathogens may not always be picked up (due to poor recovery from swabs) leading to the thought that everything is OK. For this reason I tend to concentrate on Total Viable bacterial count. This is also common advice in the UK."

By conclusion its clear that the microbial tests are dependent on the process and the product. In general its best to take yeast, Enterobacteriaceae and coliform tests are more common. Other tests such salmonella, Listeria or Cocci can be determined if they are essential or not by using proper risk analysis.

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1. Article- Microbiological Tests after Sanitation Process in Dairy