Food Hygiene Essentials

Pseudomonas bacteria are a genus of bacteria which exist widely in the environment. They are gram negative, rod shaped, non spore forming, motile, flagellated aerobes. Pseudomonas aeruginosea, probably the most well know of all pseudomonas strains, is an opportunistic pathogen that has the capability of adapting to many niches. It can infect animals and humans alike and can cross the species barrier and for this reason it is considered a potentially zoonotic pathogen. This type of bacteria is immune to many types of bacteria because it has within it’s cell wall a mechanism known as an efflux pump which pumps antibiotics back out of the cell before they have had time to take effect. It is the second most common bacterial contaminant in hospitals and it is known to be paticularly malicious in burn units where it prevents the regeneration of healthy tissue. Bacteria of the pseudomonas family are grown on blood agar which turns from a blood red color to a marine blue/green hue. It also gives off a quite pleasant slightly minty smell.

One form of Pseudomonas pathogen causes a highly contageous disease in horses which is also highly infectious to humans. The disease in horses is know as glanders because it affects the glands in and around the throat and jaws of the horse. This disease was common when colonial forces shipped large quantities of horses to places like Africa, the Middle East and the Far East. Now, this disease is more rarer. The scientific name of this pathogen is Pseudomonas Mallei and it is registered as one of the possible bacterial strains that could be used in bacterial warefare together with Clostridium Botolinum and Anthrax.

Other forms of Pseudonas bacteria are known to cause spoilage in food at low temperatures. These psicrophilic Pseudomonas strains include: P. fragi which causes spoilage of dairy products , P. taetrolens which causes mustiness in eggs and P. mudicolens, and P. lundensis, which causes spoilage of milk, cheese, meat, and fish.

The term spoilage is used in food hygiene for a condition by which the food takes on an unpleasant texture, color change smell taste. This does not mean that the food has necessarily become a serious health risk in the same way as if meat were infected with e.coli or salmonella, for instance, but at the same time it is definitely not advisable to eat spoiled food. It means that the food has been infected with bacteria which cause the physical nature of the food to change. For instance, meat may become slimy to the feel or the outer lawyer of certain foods may become pulpy, it may also smell slightly sour and change color. This happens to food which has been stored in refrigerated conditions for long periods of time in places which have not been properly cleaned with anti bacterial disinfectants. I often see this condition in places such as deli counters where meat is sliced in front of the customer.

However a little slime on meat, such as with cured pastrami in particular and with other types of processed meats is not always a sign of spoilage. It may well be due to a reaction between the protein of the meat, the curing chemicals and the air. Many manufacturers now use preservatives to prevent such spoilage. In addition, the reaction of the preservative with the air and other factors within the meat can cause the color of the product to change slightly as well. The color of the may become slightly irridescent or take on a greenish hue. If the meat smells even the slightest bit sour, feels or looks slimy or has a bad color refuse to accept it.

Spoiled food such as cured meats meat can cause stomach discomfort, diarrhea, vomiting or mild allergic symptoms in some people and may even become more serious in people whose immune system is compromised. Remember this central rule of food hygiene, “When in doubt throw it out”.

Fish products are particularly susceptible to spoilage and it can be very difficult to guess from a casual inspection if the deterioration of the fish is due to spoilage bacteria such as the psicrophilic pseudonmonas species stated above or if the cause is due to more dangerous, pathogenic forms of bacteria. If fish looks even slightly slimy, discolored or smells in the least sour don’t buy it or if it has turned bad in your fridge throw it out and clean you fridge thoroughly with disinfectant. (A tactic used by many fresh fish mungers to hide the tell tale smell of fish which has started to show signs of going off is to constantly pour sea water over it. Watch out for this trick. If you are not sure if you are smelling the actual fish or sea water, don’t buy the fish). Most importantly, keep all fish products in closed containers to avoid cross contamination with of by other food products in your fridge.

The same goes for eggs milk and cheese, if you distinguish any changes in color texture or smell, don’t take any risks, better to throw out and buy fresh. To lower the risk being sold spoiled or food which is about to spoil, buy only from supermarkets and stores which are very busy and have a high turnover of merchandise, particularly in the deli sections. Don’t be embarrassed to inspect what you buy, you are paying for fresh and healthy food and the decision to take what is on offer or not is entirely your own. The customer is always right. If you notice that the food you buy goes off quickly and you know that a). your fridge is clean and b). the temperature of the fridge is as it should be then take the food back to the store with your receipt and demand a refund or a fresh replacement. If the problem continues report your findings to your local authority for food hygiene.

At the bottom of this article you will find a full video presentation in six parts on the subject of food hygiene.

Most of us spend a great deal of attention to cases of food poisoning outside the home. Stories of food poisoning incidents hit the news and cause a great deal of anxiety and public interest. Someone once told me that food scares in the media are a bit like stories of air crashes. Although tragic and dramatic they do not amount to many deaths compared to road accidents. The same is true for incidences of food poisoning. Most instances of food poisoning do occur in the home environment.

However it is only natural to have this  concern about food hygiene from without the home because the food we buy and bring into the home environment comes from without. It is for precisely this reason that we are naturally tuned into collecting as much information as possible about where the best sources of food are and which places to avoid.

Even if we do manage to locate excellent food sources there will always be some bacteria present on it. We can never get completely away from this fact. Bacteria are everywhere. What we are looking for is sources that have not been exposed to unnecessary sources of contamination. Taking this fact into to account, the reason for promptly storing our food becomes clear. We need to keep it as fresh as possible.

Restaurants are involved solely in the preparation of food and if they work along strict hygienic guidelines the risk of food contamination is minimal. On the other hand, the home kitchen serves many functions. If only I had a dollar for the number of times I saw muddy football boots in the kitchen sink. The multi functionality of the home kitchen allows for many different possibilities for the cross contamination of food.

The kitchen is the place where any number of family mishaps are solved and family members come to the kitchen to clean themselves when really they should be using the bathroom. Kids may have been playing with their pet rabbits or the dog and the man of the house may have been unblocking a drain. In both of these instances the family members in question may go to take a drink from the fridge without properly washing and changing clothes. We all know this happens. Any kind of contaminant could spill onto food,

Another reason for food poisoning in the home is the direct and indirect interaction between the kitchen area and animal.s By animals I mean cats, dogs, mice, rats, birds, cockroaches, ants, flies, spiders, moths and in some countries maybe lizards and geckos. All animal species carry a huge variety of bacteria on their skin and in the feces and urine. Animals should not be allowed to jump onto kitchen work surfaces or eat from human utensils. If you are working with food avoid touching animals. Food should be kept in air tight food containers to stop insects and rodents from getting at it and work surfaces must be kept spotlessly clean at all times and sterilized with an anti bacterial spray such as Lysol spray.

Not everybody cleans their fruit and vegetables before storing them but I do like to wash it with a fruit and vegetable detergent. The soil upon your produce may come from many different areas of the world and it is better to clean it off than to have exotic strains of bacteria infecting your whole fridge. The special detergents for fruit and vegetables should also remove any insecticide residue from your fruit.

A major source of food poisoning in the home is failure to clean the fridge regularly and to check the freshness of the produce within it. Your fridge is a humid environment in which air circulates. This means that bacteria and molds can spread throughout your fridge in aerosol and contaminate many different items in a very short space of time. Always check your stock for food spoilage.

Preparing barbecue food is another common source of food poisoning in the home. People often leave food in containers in hot conditions while they are cooking. This gives bacteria an opportunity to grow. Grilling raw chicken takes a very long time until it is cooked through to the bone and bacteria have ample time to proliferate throughout the food. It is always best to precook chicken drumsticks, wings and chunks and to grill them just for the added taste of the grill. Thick hot dogs and burgers are also problematic for grilling on the barbecue. It takes a very long time for the heat to penetrate throughout and more often than not people eat only partially cooked food.

Thawing meat and fish. It is absolutely amazing when one learns just how few people understand how to thaw food. In the age when we constantly want things to be ready in a flash it seems time wasting to wait a few hours for meat to thaw. The solution is generally the microwave or to thaw in hot water. Both of this areas create hot spots on the surface of the meat where bacteria can develop. Meat should be defrosted in cold water but my personal advice is to plan three days ahead and defrost meat in your fridge at four degrees Celsius and in a closed container.

Ground meat and eggs are particularly sensitive items in the home kitchen. Ground meat is animal muscle whose surface area has been greatly increased. This increase of surface area is excellent for bacterial development. if other contaminants such as unclean spices or herbs are added to it as well as raw eggs, bacteria will be provided with the ideal environment. Raw egg is another perfect culture medium for bacteria. Ground meat should not be left out for long periods. It should be mixed with the other ingredients as quickly as possible and either cooked or re refrigerated until cooking. Personally I try not to exceed twenty minutes outside of refrigerated conditions.

Failure to follow manufacturers instructions is also an area in which much food poisoning in the home. Many pre made products are not suitable for baking, especially meat products which have been breaded but not pre fried.  Always read manufacturers instructions if you are using a product for the first time. Adhere to warnings stated on packaging.

The last area of concern that I want to talk about is the cleaning of eating and cooking utensils and equipment. Wash everything in very hot water and washing up liquid. Clean all grease from ovens and ranges promptly. Store equipment in clean cupboards and replace dish cloths and dish towels after each task. Use all kitchen equipment only for the function that it was intended. Personal hygiene is the function of the bathroom not the kitchen. Train your family on how to use the kitchen correctly and the risks of food poisoning in the home will be greatly reduced.