Food Hygiene Essentials

I was asked to help solve a problem concerning cross contamination and product quality control in one of the smaller fruit juice factories in our area yesterday. The factory in question has a capacity to produce 72,000 liters of various fruit juices, fruit drinks and fruit nectar and ice teas. The factory basically consists of two departments, a mixing department and a bottling department. The products are either packed in glass bottles, plastic bottles or tetra pak cartons.

All of the concentrates are poured into the 18,000 liter vats via a barrel tipping machine and a suction device for roto plasts. The concentrates are pumped through a pipe console which directs the concentrates in to one of four vats in the mixing department.

The factory had started producing tomato juice several months ago and since the onset of this production the company has been experiencing problems with the shelf life and color of products. They had tried every way they could imagine to clean the pipes leading into the tanks but to no avail. Tomato paste is very thick and viscose which makes it a difficult product to work with. Tomato paste tends to travel through pipes in pulses and because of this it coats the pipes evenly from the inside. Thinner and less solid substances such as caustic soda solution tends to run along the bottom of pipes and will only reach the top extremities for brief moments. This makes cleaning tomato paste particularly problematic.

I could smell the presence of tomato concentrate coming out of all of the pipes. There was no question that there was a grave danger of the tomato residue in the pipes fermenting. After a little thought this was my solution to the problem:

1) only to use two of the tanks for producing tomato paste. The effect this would have would be to reduce any possible risk by 50% from the outset.

2) to install separate feed pipes into those two tanks for tomato paste. This would leave the pipes for other products uncontaminated by tomato paste.

3) To dilute the tomato paste with 50% chilled water in a 500 liter mixing tank which was already on site.(2 degrees centigrade) prior to being pumped into the tanks. This would cause the concentrate to be less viscose and much easier to clean during the CIP process.

4)To dissemble and to clean the pump on the barrel tipping machine after every use.

5) To dissemble all pipes weekly and to immerse them in caustic soda solution.

6) To clean all pneumatic valves with a special industrial pipe cleaning brush from all directions.

At the end of the meeting with the department head, production manager, head of quality control and the general manager, all my suggestions were accepted and will be implemented within one working week. I will conduct a follow up check one month from today.

Last Monday morning I received a phone call from the area superintendent of the department of public health. She told me that there was a steady stream of people falling sick due to eating food prepared by one of the large kitchens in our area. She continued to tell me that her department had been through the place with a fine tooth comb but still couldn’t find the source of the contamination. I arranged to meet them at the premises in question the following day to conduct an inspection.

To tell you the truth, I had a pretty good idea what I would be looking for because I had been to that particular kitchen several times in the past and had spotted a few things that seemed problematic. However, I had to make it seem as if I was earning my money so I decided that we would start somewhere quite far from the place that I suspected to be the problem.

We started by taking swabs of everything we saw and asked staff to provide swabs, blood, urine and stool samples. We checked the toilets of staff and diners alike and took swabs from all manner of cooking pots and trays,

I knew that this kitchen was using a type of bread basket within which to thaw meats and fish. The bread baskets were stacked one upon the other and left inside the two degree Celsius anti room of the freezer complex for up to four days. I also knew that the baskets were loaded onto a low level service trolley and brought up to the kitchen. I had known the chef of this kitchen for a number of years and I also knew that it was his practice to unload the baskets into plastic tubs after the lunch had gone out to the dining room. I always made a practice of doing this first thing in the morning before we started on the days chores.

What this meant was that the contents of the baskets were left to warm up from between seven o’clock in the morning until 11 o’clock in the morning. This wasn’t a very good practice. Every chef has his ways but I knew that this was not the exact point I wanted to look at closely. What bothered me were the baskets themselves. I had a word with the chef and asked him to make an exception today and vacate the baskets earlier. What i notices was what I suspected. After rinsing the basket with water to remove the blood I saw that there was a light colored plaque stuck to the plastic. I took a scraper and saw that it came away fairly easily. I took scrapings from all the baskets used that day and then took the baskets to the aluminium washing machine to see what happened.

The man working on the machine proudly took a stack of five baskets and but them onto the machine and presses the operating handle down. The baskets disappeared into the machine for a few seconds and then came out. The worker informed me that this was a very efficient way of washing the baskets. he then placed them back onto the service trolley which had not been washed only sprayed with a water gun and placed the baskets next to the lift ready to by taken back down to the freezers.

The guy in charge of the freezer units the proceeded to re fill them with produce for another day. I had noticed several things, 1) the baskets had not been scrubbed with a stiff plastic brush of Brillo pad with detergent, 2) they had only been rinsed inside the machine which used high pressure but was ineffective due to the fact that the stacking of baskets inside the machine rendered the high pressure ineffective,3) chicken, beef, pork and fish had been set out to thaw in the same tower of eight baskets.

All of this led us to believe that we had quite possibly found the missing link of the food contamination dilemma. What had been happening was that liquid released from the thawing meat and fish had been dripping onto the plaque in the bottom of the baskets which in turn had been dripping onto the neat inside the baskets below. Then we discovered something else. The worker who had been handling the baskets went to work on the dish washing machine that cleaned the crockery and cutlery merely wiping his hands on a towel and removing his plastic apron before going onto the dish washing machine. It was his job to remove the clean cutlery off the dish washing machine. We clearly saw that he could be contaminating the cutlery.

All we needed to do now was to take the cultures we had taken back to the lab and have them checked out. These were the findings. Camphilobacter, Staph Aureus, Salmonella, e. coli, vibrio an listeria were all present in large quantities within the plaque which we removed from the bread baskets. Our findings were relayed to the company management with the following recommendations. All bread baskets to receive immediate soaking in caustic soda. 2) All bread baskets to be scrubbed individually before putting them onto the aluminium machine,3) all bread baskets to be put into the aluminium machine individually and 4) all bread baskets to receive a weekly soaking in caustic soda. 4) aluminium machine worker was to thoroughly wash his hands and change overalls before helping out anywhere else.

A re check will be conducted in two weeks from the day all the baskets were washed in caustic soda.

Caustic Soda destroys all forms or organic material. Concentrated caustic soda needs to be diluted with water and heated to a temperature of no more than 80 degrees Celsius. Caustic soda breaks down at temperatures above 80 degrees Celsius and ceases to be effective.

One job that people really fear doing most in commercial kitchens is cleaning the tough grease off equipment, drains and vents. Why? Because it nearly always involves the use of strong caustic soda based substances.

These substances cause injuries if not handled properly. They can cause blindness if they get into eyes, they can cause breathing problems and they can cause severe chemical burns to the skin. In addition they are a food safety hazard and there is always the risk that they will enter food that is in the work area.

I have used these substances for many years because we really had no other solutions to the cleaning challenges we had to deal with on a daily basis. I used to dread having to use these substances and yet, being the type of person I am I would do most of this work myself because I knew that my staff would cause themselves injury.

However, there is no longer a reason to use such potentially dangerous substances because we have now entered the era of the steam vapour cleaning system. Whereby formally you would spread degreasers onto a surface or scrape a surface for hours on end with a spatula now you can do the same work in a very short space of time using a steam vapour cleaning system.

In commercial kitchens not all work surfaces or cooking trays are stainless steel. It is better if they are but some products use aluminium to make a product less expensive. The advantage with the steam vapour cleaning system is that it cleans any surface, stainless steel, ceramic, aluminium, rubber, plastic, wood or Teflon.

It will clean, grease, grime, mould and lime. What’s more you don’t have to evacuate a twenty meter radius when using it. Once the hard grease and grime is off it becomes easy to maintain clean surfaces because very little time is needed for maintenance. In fact, the only chemical you will regularly need in your kitchen is ordinary washing up detergent. I strongly advise using a steam vapour cleaning system in all types of kitchens. Remember, the cleaner you kitchen is kept, the fewer vermin problems you will have and the easier it becomes to clean your kitchen the cleaner it will be kept.

When we talk about storage of food we are generally referring to refrigerators, pantries, larders and storage cupboards. Below is a set of principles that will help you maintain a correct food storage policy.

1) Wash out and defrost your fridge at least once a week. Clean up spillages immediately.

2) Keep all cupboards, pantries and larders spotlessly clean.

3) Check regularly for signs of mice and cockroaches, ants and such like pests. Deal with them promptly.

4) Do not keep highly perishable foodstuffs in the larder, put them in the fridge. E.G. Eggs, milk, cheese, meats.

5) Keep all cleaning chemicals out of food storage spaces. Put them in a special cupboard under lock and key. Do not use cleaning chemicals when you are preparing foods, especially concentrated acids used for removing sediment from stainless steel and de greasers such as caustic soda (NaOH) based substances or anti fungal cleaners which are usually used to clean work surfaces and walls. I will include pesticides into this category also. Store all food away safely. In professional kitchens use these substances at the end of a shift only when no food at all is out. Make sure that all these substances have been thoroughly washed away before resuming work with foodstuffs. For your own safety wear thick rubber or neoprene gloves (not surgical gloves), eye goggles, and breathing filter (a surgical mask is not sufficient) when using strong chemicals. If you are using de greasers in a commercial kitchen on large pieces of equipment or on overhead steam vents or ventilators wear a one piece plastic suit that completely separates you from the environment. If you do not you will suffer irritations, burns and/or allergic reactions to these substances. You can also damage your eyes, respiratory tract, mouth and skin. If you feel a reaction to these substances was immediately with plenty of cold water then seek medical advice if the problem is more than very superficial or if there is continued irritation. (caustic soda gives the skin a slimy feel and one can know it had been washed off successfully when the sliminess has gone).

6) Food storage spaces should be designed to stand against interior walls only. This will serve to ensure that these places will always be cool and dry.

7) Do not run water or drainage pipes through places where food or food utensils are being stored.

Be sure to rotate your supplies thoroughly. Remember this saying, “last in, last out”.

9) Keep animal food, such as cat food and dog food, separate from human food! Also keep animal eating dishes separate from human eating utensils. Do not wash your dog bowl or cat bowl together with dishes that humans eat from. Animal dishes should not be put into dishwashers.

10) Try to keep raw and unclean root vegetables in a separate storage area but failing that keep all root vegetables at the very bottom of the storage area in suitable closed containers. (special storage solutions can be found on the market that allow the vegetables to breath)