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.

A few weeks ago a leading Israeli fruit juice manufacturing plant had several hundred tons of water melon concentrate condemned by the ministry of heath on the pretext that there were unacceptable contaminants within the juice.

The concentrate in question was destined for use on the home market where it is used by the ice cream and iced lollie factories to manufacture a popular range of water melon flavored products. This set back has put additional pressure on a market sector which is already struggling to survive the current market recession.

Israel has suffered several consecutive years of very low rainfall. The sea of Galilee which is the major fresh water reservoir for Israel and it’s neighbours has reached dangerously low levels and as a result of this crisis water prices have risen several fold. As a result of this new state of affairs the profit margins in which vegetable and fruit growers operate have been cut even further and it is really uncertain from year to year if it will be worth growing anything at all.

The jordan valley which enjoys a milder winter than many other parts of Israel is famous for producing early fruit and vegetable harvests both for the home and export markets.

Seemingly, some of the areas water melon growers took it upon themselves to irrigate this years water melon harvest that was intended for industry with grey water instead od fresh water. The logic behind this decision being that grey water does not contain more contaminants than those already presant in ordinary soil.

What is not clear is if the water used for irrigation was indeed just grey water or if the suppliers of the grey water added certain quantities of first stage black water filtrate to the grey water that was being supplied to the farmers. It is also possible that the farmers used grey water for the initial stages of germination and consequent stages before the development of the water melon itself, switching over to fresh water once the melon began to develop. In any case, whatever the sequence of events was, contaminants entered the melons.

Samples of the water melon concentrate were tested both for chemical and microbial contaminants and found to test positive for both categories of contaminates within the concentrate. the concentrate was deemed to be a risk to public health and presented a food hygiene problem. The water melon concentrate was condemned and will not be used to make the iced products that it was intended to make.

The case is being looked into more closely by the public prosecutors office and charges are expected to be issued to those responsible for taking these regretable discisions to used contaminated water for growing water melons.

What is listeriosis?
Listeriosis is a bacterial infection caused by the bacterium Listeria monocytogenes. Until several years ago it was thought that this bacteria only infected animals but it is now accepted that humans are also at risk from this disease. While many bacteria are generally seen to infect specific locations within the human body, Listeria may infect many different locations, such as the brain or the spinal cord membranes or the bloodstream.

Classification:
L. monocytogenes is a gram positive, non-spore forming, motile, facultatively anaerobic, rod shaped bacterium. It is catalase positive, oxidase negative, and expresses a Beta hemolysin which causes destruction of red blood cells. This bacterium exhibits characteristic tumbling motility when viewed with light microscopy. [6] Although L. monocytogenes is actively motile by means of peritrichous flagella at room temperature (20-25C), the organism does not synthesize flagella at body temperatures (37C). [7]

Who gets listeriosis?
Anyone can get this disease, but those at highest risk for serious illness from this bacterium are newborns, the elderly, people with weakened immune systems, and pregnant women. Healthy adults and children occasionally get infected with Listeria, but they rarely become seriously ill. Listeria Monocytogenes is classified as an intracellular paracite. This means that it invades and lives within cells of the body thereby managing to evade the body’s immune system. Infection by as few as 1000 individual bacteria is considered enough for the disease to take hold. When listeric meningitis occurs, the overall mortality may reach 70%; from septicemia 50%, from perinatal/neonatal infections greater than 80%. In infections during pregnancy, the mother usually survives.

When do Listeria infections occur?
Infections occur throughout the year. Although most cases occur sporadically, food-borne outbreaks of this disease do frequently occur. Poor food hygiene and poor personal hygiene conditions are responsible for many of the recently recorded outbrakes.

How is listeriosis spread?
Listeria bacteria are widely distributed in nature and can be found both in water and soil. Infected animals may also serve as sources of contamination. Unlike other organisms, Listeria can be spread through several different methods. Ingestion or food-borne transmission of the organism, such as through the ingestion of unpasteurized milk or by the eating of contaminated vegetables, is often a source of many cases. In newborn infections, the organism can be transmitted from mother to fetus in utero, or directly to the fetus at the time of birth through the contact of the fetus’ blood supply with that of the mothers. Direct contact with the organism can cause lesions on the skin.

What are the symptoms of listeriosis?
Because listeriosis can affect many different parts of the body, the symptoms vary. For meningoencephalitis, the onset can be sudden with fever, intense headache, nausea, vomiting and signs of meningeal irritation. In other body locations, various types of lesions at the site of infection are the primary symptom. In most cases, Listeria infection causes fever and influenza-like symptoms resembling a host of other illnesses.

How soon after exposure do symptoms of listeriosis appear?
Listeriosis has an extremely variable incubation period. It can range from 3 to seventy days, but symptoms usually will typically appear within a month of infection.

How is listeriosis diagnosed?
Specific laboratory tests are the only way to effectively identify this disease. Since many cases may be mild, the disease may be much more common than is realized.

Are there any unusual features of listeriosis?
Listeria infections are a significant risk for pregnant women, who may not experience obvious symptoms. Infection of the fetus can occur before delivery and can cause abortion as early as the second month of pregnancy, but more often in the fifth and six months. An infection later in pregnancy may cause exposure during birth, sometimes resulting in infection of the newborn child which may be fatal.

Does past infection with Listeria make a person immune?
Past infection does not appear to produce immunity.

What is the treatment for Listeria infection?
Several antibiotics are effective against this organism. Ampicillin, either on it’s own or in combination with other types of antibiotics, is frequently used.

What can be done to prevent the spread of Listeriosis?
Since the organism is widly distributed throughout nature, basic sanitary measures such as only using pasteurized dairy products, by only eating cooked meats and washing hands thoroughly prior to the preparation of foods offer the best protection against infection by this disease.

In addition, the following recommendations are for persons who are categorized to be at high risk of infection, such as pregnant women, the elderly and persons with compromised immune systems:

Do not eat hot dogs, luncheon meats, or deli meats, unless they are reheated until they are steaming hot.
Avoid getting the liquid from hot dog packages onto other foods sources, utensils, and food preparation surfaces, and remember to wash hands after handling hot dogs, luncheon meats, and deli meats.
Do not eat soft cheese products such as feta, Brie, and Camembert, blue-veined cheeses, or Mexican-style cheeses such as queso blanco, queso fresco, and Panela, unless they clearly state they are made from pasteurized milk written on the labelling of the product.
Do not eat chilled pâtés or meat spreads. Canned or shelf-stable pâtés and meat spreads can be eaten.
Do not eat refrigerated smoked seafood, unless it is contained in a cooked dish, such as a casserole. Refrigerated smoked seafood, such as salmon, trout, whitefish, cod, tuna or mackerel, is most often labeled as “nova-style,” “lox,” “kippered,” “smoked,” or “jerky.” The fish is found in the refrigerator section or sold over deli counters of grocery stores and delicatessens and supermarkets. Canned or shelf-stable smoked seafood may be eaten.

There has always been a lot of speculation around the reason the humble pie was invented. Nowadays our adoration of this clever invention is liable to cloud the objective perspective of those who lived in bygone years. A pie is made of two main ingredient categories, 1) a crust and 2) a pie filling. Nowadays we can enjoy a vast array of crusts or pastries. Their flavors and textures vary to suit both the filling and the sensation that the pastry chef wants the diner to enjoy.

Man has know how to make dough for many thousands of years. Ever since man began to gather cereal crops he has experimented with the possibilities it presented him with. Whole grain bread, in one form or another has been a staple of many civilizations throughout history. Initially, it would have been the job of the women of the house to make bread in a small earthenware oven. As man moved from living in extended family groups or clans resources began to come under the control of chieftains.

This had several consequences for the common man. 1) he had to find ways of pooling resources in order to use fuel more efficiently, 2) if fuel was to be used at a central place somebody would have to be chosen to oversee the baking of the bread. 3) if people would have to pay for these services they would have to work more outside of the home to cover the cost, 4) if they mad less time to mill the grain somebody would have to undertake that function too. And so two important professions were born. The baker and the miller. Now I know that in explaining this process in this way it may seem that I mean that this happened overnight. No, this was a process that may have taken quite some time.

So now we have our bread being baked centrally. What has this got to do with pies you may ask. OK, I’m building up to it. A baker has to keep his oven very hot and at a constant temperature. Because of the design of the bakers oven it has the capacity to hold residual heat for a very long time, even after no more fuel is added. We have already defined heat as a resource that people of bygone eras could not let go to waste. When the baker was not using his oven for baking he would earn a bit more money by letting the women of the village put their pots of stew or hot pot into the oven to cook slowly overnight. This was a very clever idea that was used in many European villages until quite recently and maybe still is in some remote areas.

Now bakers had boys or apprentices working for them who did not get very much to eat. To see an oven full of stew pots simmering away in the oven would have been a type of torture for them and it is told of an evening they would sneak back into the bakery and sample a “little” from all the pots in the oven. The ladies who had given the cooking of their stews to the baker were very disconcerted to find that the level of their pot had reduced somewhat more than they had anticipated. They looked for a solution for this ongoing problem and eventually came up with the idea of wrapping a piece of dough around the rim of the pot and the lid. The pot was now effectively sealed and woe betide the bakers apprentice who broke into one of those seals.

During the evolution of mankind trial and error has led to a great number of observations and the very same ladies who used the bakers oven to cook their weekly stew would have undoubtedly noticed that the condition of the stew would have been better with the pastry seal left on than if it were removed. This would have led to the observation that factors leading to the spoilage of cooked food came from without rather than from within. Therefore, maintaining the state of separation from the environment was seen to preserve the “shelf life” of your stew or hot pot. In those days this was very important news indeed.

If pastry or a dough surround was accepted as being the secret of preventing the rapid spoilage of food, could it be possible to put a filling into pastry and cook it in an oven when one needed to make smaller more individual portions of food? Experimentation along these lines obviously happened. The original ides would have been to eat the filling and discard the pastry crust as if probably wasn’t designed for taste in those early days. As time went on it was obviously realized that to discard the crust was a waste of food resources and hence bakers and women alike began to experiment into ways of making the pastry an integral, edible and tasty part of the pie “experience”. The next time you eat a pie, give a thought for how important it’s development was to the growth of civilization as we know it and the development of insight into food hygiene.

Food hygiene is a subject which is of concern to everybody in the world every day of their lives. To many people around the world the ability to find safe sources of food and water are very real questions of survival. Everybody has an interest in eating to maintain good health.

From a very early age we are taught that rancid food is bad for us and we posses physiological mechanisms which trigger very adverse reactions when we come across food which possesses qualities which do not suit those to which we recognizing as safe. Our parents teach us the guidelines which we use to appraise the edibility of our food and water.

Scientists have discovered that out prehistoric ancestors often scavenged for food but although they scavenged they still made sure that the food they ate was still quite fresh. Prehistoric man would follow carnivores as they hunted for food or would have followed other scavengers such as vultures which only eat fresh meat. By waiting for the carnivore to finish it’s meal from a safe distance primitive humans were able to quickly move in on a kill and eat the meat scraps that were still left on the bones and, seemingly, to eat the bone marrow inside the bones by developing the skill of crushing them with stones. Early man obviously competed with other scavengers for these spoils but smaller animals would have quickly learned that early man moved around with implements which could be used to attack. Namely the stones with which they split the bones to get at the bone marrow. This would have been the point in evolutions in which many animals learned to fear man.

By following carnivores to their kills early man would have been able to ensure that the meat he was eating was no more than a few hours old as as such was as fresh as was possible to hope for, given the circumstances of those primitive conditions. In order to ensure that he was second only to those top predators, man had to establish himself as second in the pecking order for food. Yet although primitive man was second only to the top predators in pecking order in one sense it would have been an absolute necessity to develop the skills necessary to control the environment around the kill zone for several reasons. The first reason the first reason would have obviously been to ensure personal safety. Another reason would have been having the ability to chase off the predator once he has eaten enough and was too tired to resist effectively. Yet another reason would have been to prevent the carcass being stolen by rival human tribes or other animal species. However one cannot dismiss that a major reason in establishing a high level of control around the kill zone and making a timely move in on the spoils would have been to ensure that they meat still left on the carcass was still fresh enough to eat. So this sense of timing would have been a key factor in the food hygiene regime of early man.

My personal estimation is that this time period would have been anything from one to six hours after the kill. We also know that prehistoric man had a much more robust immune system that we do today. Things that primitive man could eat to no ill effect would make us quite ill. The range of foods which he would have eaten was far more extensive that what we eat (with the possible exception of the Chinese). Cooking and sterilization of food would only become known to man after he attained the ability to make and control fire.

So from these facts we know that food hygiene, at a very basic level has always been a fundamental concern to mankind.

Question. Could the necessity to chase carnivores and other scavengers from a carcass have brought about the advent of designing and using weapons as we know then in more recent history? Could having an array of weapon choices have provided prehistoric man with the ability to further control a hunt scene by hunting alongside certain species of carnivores (such as canines) while both they and their quarry were distracted by the hunt? Could this possible situation have led to the eventual alliance between man and canine? Would the realization of the benefits of developing the skills needed to exploit such opportunities have played a key role in the evolutionary development of mankind and eventually lead to his gaining the ability of placing himself at the top of the animal kingdom hierarchy?