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salmonella-549608_1280Today’s post is a story that I heard from a colleague about a vegetable processing plant that became infected with salmonella and e. coli.

Please understand that this is a major international company and it is for this reason that I cannot disclose any names in the content of this article. This particular plant buys vegetables of all sorts directly from large farms and after grading, cleaning and sorting the vegetables are frozen and packed for the consumer and institutional markets.

The company in question works with just two or three trucking companies which bring the raw materials to the plant and deliver shipments of finished product to the local and foreign markets. Good relationships had been established with the trucking companies which included both the haulage companies and the factory itself helping each other out as much as possible as a matter of course. This factory had the best weigh bridge in the area and one of the favors that was performed on an ongoing basis was to weigh trucks of the said three companies even though the payload of the trucks had nothing to do with the business of the factory.

Complaints had been arriving at the factory’s quality control department stating that their products had tested positive for salmonella and e.coli. The factory checked all of their production lines to check that everything was working as it should and indeed no faults were found inside the factory itself.

A decision was taken to bring in an expert in the area of HACCP’s. and indeed it took him a mere five minutes to discover the source of the problem. Many different types of trucks were coming in to be weighed. Among them were trucks hauling the following cargoes: cages for chickens and turkeys being shipped from farms to slaughter houses, deep litter from dairy farms and poultry farms, various types of manure, and soil.

Trucks carrying these loads often waited for quite some time alongside trucks hauling vegetables for the factory itself. Dust and spray that inevitably flew from one truck to another was enough to cause the cross contamination of the vegetables with whatever the other truck was hauling.. This was a very basic and critical flaw in the work procedures and food hygiene standards of this particular factory. This situation was more than enough to cause this food hygiene crisis for this particular factory.

A decision was instantly taken to stop the weighbridge service to all trucks not carrying vegetables specifically for the plant. In this particular case, good intentions led to a very bad result.

animal-655308_1280I can remember when I was about fourteen years old I went on a school trip to see a steel mill in Sheffield England. Three things impressed me on that trip. These three things were the noise, the heat and the rats. I could hardly believe my eyes. Not a bite of food in sight and yet rats were scurrying around not twenty yards away from where we were walking.


I can remember wondering why rats would bother about a steel mill. There was not a morsel of food in sight. It was not until fifteen years later that I would find the answer to that question.  Yet the fact remains that rats do infest many types of factories.

If the common denominator for rats establishing presence in factories and mills wasn’t food then what was it? In 1991 I began a course of practical Engineering in agriculture. It was during this course that I found out why rats infested many types of industrial plants. The reason is copper. Mice have trouble getting enough copper to be able to operate their immune systems and the missing link that enables them to do so is copper.

All industrial operations run on electricity and electricity runs through copper wires. Rats peel away the plastic coating on electric cables and lick the wire to get more copper and they do this obcessively. People who have worked in factories will know that from time to time they will hear an almighty bang. More often than not this bang is caused by a rat short circuting an electric cable. Needless to say that the rat is dead.

Why an I telling you this? Because one needs to understand that if rats had no reason to infest a food factory, they would still be there because of the copper wiring.

Food factories can be categorized into two main categories. Ones that process raw agricultural produce, plant or animal and ones that process food that has already been processed for industrial use.  In the first example produce is brought from the farm or co-operative sorting plant to the factory. Here the produce is tipped, washed, sorted and peeled or alternatively slaughtered, skinned, gutted and cleaned in the case of most animal produce.

In both cases the amount of dirt and contamination that is around at this intitial stage of the game is quite unbelievable and it is at this stage of the process that most rats are found. Only an ongoing, organized and regular cleaning regime can reduce the presence of rats and mice.

Once the produce has finished this init ial stage it is then passed to the next stage. Whatever the stage the amount of dirt should be very minimal compared to that of the first stage. As the product progresses towards packing the work environment should be almost sterile in comparison.

There are systems that analyze the risks and points at which one can reduce risks to food products. One such system is called HACCP. HACCP means hazard analysis and critical control points. In this system each hazard is defined and critical control points at which the level of the hazard can be reduced, eliminated or controlled are also defined and adopted.

There may well be one sequence of actions to control vermin and an entirely differnt sequence for the control of bacteria, for instance. It is the job of management to ensure that workerd are familiar with all the various sequences and to make sure that they are adopted and applied.

When this system is implemented in all of the factories various departments threats such as salmonella poisoning from rats is greatly reduced. Trouble can start when priorities and sequences are changed for one reason or another. The enemy of the HACCP system is cut backs. Cut backs in staff or cut backs in spending. Right now we are in the midst of a recession. In recession we can expect cut backs on more or less everything.

In plants where produce is immediately pumped through stainless steel pipes the opportunity for vermin to contaminate the produce is greatly lowered. Businesses such as bakeries may enocounter problems with rats at the end of the process rather than at the initial stages. For some reason mice  rats and cats do not seem to like white flour and prefer to wait until it has been transformed into bread products. Here pest control is particularly important because there is no process between contamination and the consumer that will kill the bacteria that have been transferred through cross contamination.  Nothing should be left unattended at this stage. Nothing should be but directly on the floor and nothingshould be put into plastic trays that have not been washed thoroughly in a proper industrial manner. To fail to be attentive to this points can cause indirect contamination via contact with vermin excretions.

The golden rule is to leave noting to chance. Always pre suppose that anything that can happen in theory will happen in practice.

Just how many articles need to be written about pistachios? Well, obviously one more because now I’m writing one too.

Ok, so lets look at the facts. We know that the nuts were rodent infested and that salmonella bacterium were found to be present in the nuts. Ok, sounds reasonable! food hygiene standards were down and a few dirty little mice or rats got at the nuts.

Here’s a video demonstrating the somewhat less than delicate method of harvesting pistachios

Excuse me! Don’t all types of nuts, seeds and grain attract rats anyway? Don’t pistachios grow in the open environment where field mice, cute little chipmunks and a whole host of other little critters frolic to their hearts content. OK, the mice and rats that infest wharehouses, sewers and industrial areas are not quite the same as those found in nature, right?

The answer to this is yes, and no. And another question comes to mind. Is salmonella the only dangerous bacteria spread by rodents? The answer to this is NO. Rodent urine very often contains a bacteria called leptospira which infects other species with a desease called leptospirosos. Rodents have no control over their excretions and there fore wherever they go a trail of their infected urine is left behind. This is how many snake species track rodents.

Leptospirosis is a very unpleasant desease which can require up to three weeks in a hospital bed to recover from. It is a zoonotic desease and is often contracted by fishermen who work on wharfs, dairy workers and other professions involving animals or places where rodents congregate such as sewers and feed bins. Leptospira as a species is far more heat resistant than salmonella. We should remember that not all deseases involving food are contracted through ingestion. Some, like leptospirosis can be contracted through healthy skin, especially when wet.

Rodents may also be responsible for the spreading of other forms of bacteria such as camphilobacter, staphilococcus aureus, clostridium spp. pseudomonas aeroginosa and many more. All of which can cause serious illness and similarly to leptospira are more heat resistant than salmonella.

But let’s say for a minute that in spite of all these other possibilities salmonella is our prime concern. What could have happened that caused the bacteria to remain alive? They are roasted and salted, right? In theory that is correct. Pistachios are typically roasted and salted if they are left in the shell. If they are taken out of the shell they may be sugared in which case the pistachios are dipped into boiling sugar syrup and cooked in an oven so that the sugar crystalizes.

If salmonella remained alive on the nuts it is clear that they did not receive sufficient roasting. Could it be that the second largest pistachio distributer in the ‘US of A’ did not roast his nuts adequately? What’s going on? We have been chomping these nuts for years why the problems all of a sudden? Were there no rodents then?

We are in a recession, right? Cuts in costs have to be made, right? Could it be that workers were instructed to change the control setting on the roasters to a lower temperature and/or keep the nuts within the machine for a shorter period of time.

As I said, salmonella is by no means the only health risk where pistachios are concerned. We have not even started to discuss liver cancer causing moulds that have been found on pistachios all over the world.

One thing that I can assure you is this, just about every pistachio that you will ever eat has been in indirect or direct contact with a rodent at some stage of its production. It is all but impossible to keep rodents away from this type of crop in the natural habitat. The problem that occured here is one of HACCP’s and GMP. In my opinion critical control points were disregarded in the interest of saving money. This could include pest control within the processing plant also.

The moral of this story is that if you don’t want to loose big time, don’t try to save small time!

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