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Food SafetyHaumaru Kai

Information about food safety - hygiene, food handling, safe handling practices - Clean, Cook, Cover, Chill

Food Safety

food safety. Clean

Only handle food with clean hands. Always wash hands;

  • Before handling food
  • After handling raw meat and poultry
  • After going to the toilet, or changing nappies
  • After handling pets
  • After gardening

Clean hands are hands that are washed and dried on a clean towel. Wash knives and utensils, and scrub chopping boards between preparation of raw and cooked foods.

Cook

  • Defrost frozen foods in the fridge before cooking, not on your bench top
  • Cool hot foods, covered, for no more than 30 minutes before refrigerating
  • Reheat leftovers until steaming hot throughout and do not reheat them more than once
  • Chicken, meat patties and sausages need to be cooked thoroughly

Pre-cook these meats before barbecuing. Do not put cooked meat back on the same plate that held raw meat. Ensure there are no traces of pink meat or juices before eating.

Food borne illness is caused by bacteria which are able to multiply very fast in moist, warm conditions where they have a suitable food source. Handling food carefully can stop the bacteria from getting to levels where they cause illness. Cooking food thoroughly helps kill the bacteria and chilling food stops the bacteria from multiplying. Clean hands and utensils and covered food helps stop the bacteria spreading.

Cover

  • Cover foods before storing in the cupboard or fridge.
  • Store raw and cooked foods separately.

Store raw meats in the bottom of the fridge to ensure juices don't drip onto other foods.

Chill

  • Bacteria causing food borne illness thrive at room temperatures - keep food very cold or very hot.
  • A chilly bin is a good way of keeping chilled products cold when taking them home from the supermarket.
  • Put a frozen chilly pad with your picnic foods to keep food safe.

 Remember to check the use by dates - If in doubt, throw it out!

These days time is short. It is commonplace to allow only 30 minutes to prepare the main meal of the day. We demand convenience and we also want foods with fewer preservatives and additives. We want fresh foods but we only want to shop once a week. With new technology industry has delivered a huge range of fresh ingredients and ready to eat, ready to heat or ready to cook meal solutions. These foods are very convenient but must be looked after properly to keep them safe. The incidence of food borne illness in New Zealand is at an all time high.

Please help to improve the statistics by following some simple rules when handling food in your car, home or garden.

Keeping Safe

Some foods are harmful right from the start, such as poisonous mushrooms, rhubarb leaves and some berries. Some foods become harmful due to changes that occur in them, such as diseases or contamination with foreign substances. For instance, some grains can become diseased with a fungus that produces very poisonous toxins. Some foods (especially in countries like Africa) become contaminated from unsafe water supplies that may have parasites and diseases in them. The types of harm that can come from food can come from the following sources:

  • Bacteria may get into food via soils or water in plants, or via the skin or gut of an animal at slaughter. Depending on the type of bacteria, they may cause illness simply by being present, or they may produce toxins in the food or later in the person who ate that food. In New Zealand, most of our food borne illness is caused by bacteria. These will be discussed in more detail shortly.
  • Fungi and moulds can also grow on many food types. Some are not harmful, but others can make toxins in the food which are very poisonous. It is neither safe nor appropriate to sell or serve food that has become mouldy with fungus, unless it is supposed to be, such as with blue cheeses.
  • Viruses are becoming a more likely cause of food borne illness in New Zealand. They are most likely to get into food from water or unsafe food handling by an unwell food preparer. More on these later also.
  • Parasites such as gut worms, protozoa such as giardia and cryptosporidium and other parasites are likely to get into food from contaminated water or from soil dust, or poor food handling by an ill handler.
  • Chemicals are most likely to get into food from cleaning agents, pest control agents or as metals from improper storage in tins and such.
  • Some poisons come from the foods themselves, when people wrongly prepare a food which is poisonous, such as decoration with poisonous garden plants. Some poisons are ingested by the food when alive and passed on to humans, such as with shellfish that have eaten toxic algae then becoming poisonous themselves.

Food Borne Illness

There are many types of food borne illness. Illness can be due to spoilage, contamination, infestation, bacterial load or toxins produced by bacteria or moulds.

Wholesomeness

Let's face it , you're in the food business, you want to make money from your food. It makes sense to have that food look good as well as taste good so that it attracts your customers in the first place. A sandwich that's starting to curl at the corners or a hunk of steak that's green and slimy just aren't attractive - and they might be harmful to eat. Food that doesn't look good may or may not be harmful, but it will certainly turn off your customers anyway.

Spoilage

Food spoilage occurs mainly as a result of chemical reactions involved in the process of aging and decay, through the action of bacteria, or through a combination of both.

In addition, drying, staling, contamination and damage by pests can assist in food spoilage.

Chemical food spoilage in food aging is caused by enzyme reactions natural to the living organism, continuing on after it has been slaughtered or harvested. For example, ripening once picked, continuing on to rot level. Initially these changes in meat make it more tender and flavoursome, but then it continues on to 'sogginess' and putrefaction if not stored at the correct temperatures. Also in meat, the fat may become rancid through oxidation. This causes what is most commonly recognised as 'off' flavours in cooked meat. Fish is much more susceptible, as being a cold blooded animal, it requires much colder temperatures to delay the decay process.

Microbial food spoilage may be due to either bacteria or moulds and yeast, but the more harmful tend to be the bacteria. Food spoilage is caused by changes in the food caused by their feeding on it, and their waste products. However, in many cases the food spoilage is not as harmful as the simple presence of the bacteria. Microbial contamination usually comes from damage to the food. In meat it usually occurs at slaughter when natural bacterial infestation of the skin and intestines of the carcass contaminates the meat itself.

Spoilage isn't necessarily harmful - rubbery carrots aren't likely to cause illness - but it might be and you can't always tell.

To avoid food spoilage, eat it fresh, store it refrigerated, cook it soon after purchase, eat it soon after cooking. Choose fruit and vegetables with clean, intact skins, meat that isn't slimy, green or smelly, and other foods that aren't mouldy or dusty.

Contamination

There are three possible types of contamination to be avoided.

  • Physical contamination
  • Chemical contamination
  • Microbial contamination

 Physical contamination is basically the presence of some foreign object that shouldn't be there. It could be harmful, like a piece of broken glass; or it could be merely offensive, like a freshly washed slug on your salad. Many foreign object contaminations can be both harmful and offensive, such as hairs, broken fingernail, dead insects and many others that you can't even tell what they were! It doesn't matter - if it looks like it shouldn't be there it will offend your customers and you could be liable for an Offence against the Food Hygiene Regulations or the Food Act.

Be aware that even something harmless but offensive can make people violently ill - the body recognises WRONG! - EJECT! and deals with it on a subconscious level. You just lost a customer, and many of that person's friends as well.

Chemical contamination usually comes from inappropriate storage of cleaning solutions and pest control poisons. Make sure any non-food items are always stored in a marked container so that they cannot be mistaken for anything else. They must also be stored somewhere away from food and food items so that any leakage of the containers cannot contaminate any food or food item.

One restaurant was brought to a close forever by making a whole night's customers very ill indeed by contaminating food with dishwashing liquid because it had leaked from one shelf down to another and contaminated a commonly used ingredient.

Microbial contamination is the most common form of contamination and the most potentially harmful. Contamination could be by bacteria, viruses, yeasts and moulds or other microscopic "bugs". Some foods will be naturally laden with bacteria, such as raw meats, but most foods get their microbial contamination from the food handler, pests or from cross-contamination from other food items via things such as knives, cutting boards and slicers that have not been properly used. (More about prevention of cross contamination later).

Illness resulting from excessive bacterial growth can be of two types:

Food infection is illness caused by the presence of the bacteria itself, usually due to multiplication of the bacteria to large numbers over a length of time. Illness may not occur until some time after consumption of the contaminated food. Symptoms of the illness will be specific to that bacteria.

Food poisoning is illness caused by toxins released from the bacteria. Illness is likely to be more severe and have a more rapid onset. Prevention of bacterial contamination and control of growth are essential because some of these toxins are resistant to average cooking temperatures.

Moulds may also cause food spoilage activity, but still be desirable and harmless to eat, such as in blue cheeses. Meats, breads and sweet foods are also likely to be attacked by moulds. These are not generally harmful, but like bacteria, moulds can release toxins - especially those found on nuts and cereals, so it is best not to eat them.

In New Zealand, our biggest cause of unsafe food is bacteria. If you prevent and/or control the harm from bacteria, you will probably control the other potentially harmful sources. In some cases you will be preventing them getting into the food in the first place. Or, you may be controlling their numbers so that they are not harmful, or you may be actively killing them off. Whatever the circumstance, food must be ensured to be safe to eat at all times.

High and Low Risk Foods

Different foods carry different risks of becoming harmful to eat depending on factors such as water content, sugar levels, acidity, salt content, protein levels, natural bacterial load, exposure to air and how we prepare and eat them. Foods may be considered to be stable, semi-perishable, perishable, raw or cooked. For example:

Toast is more stable than bread because the lower moisture content doesn't support mould and bacterial growth as well. Similarly, raw meat will rot faster than cooked meat – but here's the trick – the cooked meat is more risky as it is likely to be eaten as is, whereas the raw meat is likely to be cooked and rendered safe. You must consider foods that are ready to be eaten as is the most risky as any abuse of them may not be over ridden before they are eaten.

High risk foods include:

  • Cooked meat and poultry
  • Cooked meat products such as pies, gravy, sauces, soups and stocks
  • Processed meat products
  • Some meat cuts eaten raw or rare
  • Shellfish
  • Milk , cream, custards and other dairy products
  • Cooked rice
  • Eggs, especially if raw, egg products, custards, mayonnaise

 These foods are readily perishable due to being excellent food sources for bacteria and therefore prone to spoilage and infection. Many of the bacteria associated with these foods are also toxin producing, leading to food poisoning also

Lower risk foods include:

  • Jams and chutneys
  • Pickled foods
  • Foods preserved in brine (salt)
  • Dry foods such as flour and grains
  • Foods preserved in alcohol or oil

 This is because bacteria need a warm (room temperature), moist environment to survive in that provides some food source. Bacteria cannot live in any food that is high in sugar, acid, salt, alcohol or oil.

Some bacteria need a supply of oxygen, some mustn't have it so it is difficult to use air supply as a control tool for food safety.

Food preservation by drying, salting and smoking, sweetening and acidifying provides environments that bacteria cannot survive in. But they must be done properly to avoid toxin production. Preservation by heating as in canning and pasteurisation kills off the harmful bacteria. Sealing to prevent re-contamination is essential. In some countries, food is preserved by irradiation. Although there has been shown to be no residual radiation, with excellent preservation results, this is not allowed in New Zealand or its imports.

Bacteria

Bacteria are microscopic (can only be seen through a microscope) living cells which are found naturally in the air, in the soil, in the water, on work surfaces and on people, animals and insects. They are around us on us and in us every where and all the time. Most bacteria are harmless, indeed we need them to stay healthy. Bacteria help our guts to digest food, they are used to make many foods such as cheese, wine, beer, yoghurt and medicines such as penicillin. Many of our body's bacteria fight harmful bacteria and keep us healthy.

Some bacteria are what we call pathogenic, or disease causing. Some are what we call opportunistic - in the right place in the right numbers they are harmless or even beneficial, but in the wrong place or at the wrong numbers they can take advantage of the opportunity to become pathogenic. Many of the 'gut bugs' or intestinal bacteria are opportunistic - in the gut they help digest food, but once they get back into the food and are themselves being digested they become pathogenic and cause illness.

Bacteria need a warm, moist environment to survive in with a food source and they may or may not need oxygen from the air to survive. If we provide these things for them bacteria will not only survive but multiply in our food to levels where they are harmful to the person who eats that food. And they multiply incredibly rapidly. They can be in their billions within hours of colonising a site.

Some bacteria can survive cooking by forming spores, or protective shells around themselves like an insulating coat. After the heat is off they can then turn back into their normal form and begin multiplying again.

Some bacteria can also make toxins or poisons and release these into the food while they are multiplying, thus making the food very harmful to eat. Some bacteria do not make their toxins in the food but in the person who eats them. When the bacteria laden food gets into the person's stomach, which is acidic, they release toxins as they forms spores to protect themselves from the acid, thus making the person very sick indeed.

Salmonella

Salmonella may be already in any meat, eggs or shellfish or raw milk as it can get there from the skin or intestine of the animal at its slaughter (or at milking in the case of raw milk). It doesn't make spores or toxins so it should be easy to prevent by simply cooking the food properly. It will be destroyed at 75 - 80°c. It is also likely to get into any food from the food handler not washing their hands or utensils after handling raw meat or dairy products.

Symptoms of illness include fever, headache, abdominal pain, diarrhoea and vomiting. Illness is likely to begin 12 - 36 hours after eating the food and may last for 1 - 8 days.

Campylobacter

Campylobacter is very similar to Salmonella in that it is likely to be present in meats, shellfish, raw milk and foods contaminated by the food handler. It does not make spores or toxins and can be killed at temperatures of 75 - 85°c. The difference is that we need a large number of salmonella bacteria in the food to make most people ill, but we only need a small number of campylobacter bacteria to make most people ill. Because of this it is also possible to get campylobacter bacteria into us from hand to mouth contact with an infected person. For example: they have campylobacter and haven't washed their hands after going to the toilet, you shake their hand as you greet them, then put your finger in your mouth for some reason. Hey presto - now you have campylobacter too!

Symptoms of illness include fever, headache, nausea, vomiting, haemorrhagic diarrhoea and severe abdominal and muscular pain. Illness is likely to begin 1 - 10 days after eating the food and may last between 2-3 days but relapses can occur.

Listeria

Listeria is an extremely common bacteria found in water, soil, plants and faeces. Foods affected by listeria are most likely to be shellfish, vegetables, raw milk and highly processed foods such as soft cheese, hams, pate e.t.c. The trouble with listeria is that it can still multiply quite happily in the fridge (which would usually be too cold for most bacteria). However it is killed easily at temperatures of 75 - 80°c

Symptoms of illness in a healthy adult are very similar to the 'flu and many people may not even realise they have a food borne illness. However, the very young, very old or immunocompromised may develop the full symptoms of septicaemia or meningitis, which can kill. This also applies to unborn babies. Mum may not get much more than slight 'flu symptoms, but her baby may die before it's even born.

You may not be able to protect all your customers from Listeriosis, depending on the type of food you produce, but you should still be aware of its dangers, even if only for your own use.

Clostridium perfringens

This bacteria does form spores to survive heating and produces toxins in the gut of the consumer. It is commonly found in the intestines (gut) of animals and humans and can be assumed to be present on raw meat from contamination at slaughter. It is also commonly provided by the unwashed hands of a food handler. Flies can also contaminate food with clostridium perfringens by bringing it in on dust and soil.

The time spent in between hot and cold is the most vital time to be controlled to prevent this bacteria being harmful. The raw meat must be assumed to have the bacteria present. If it is cooked properly, most of them will have been killed but some must be assumed to have survived by forming spores. If the meat is then left at room temperature for too long, these surviving bacteria will begin to multiply again. If they are then eaten, as they meet the acidic contents of the stomach they form spores to protect themselves and release toxins as they do, thus making the person who ate them very sick. This could have been prevented by either eating the food as soon as it was cooked, keeping it hot at over 65°c until it was eaten, or cooling it rapidly and either eating it cold or reheating it to over 80°c. It is the time at room temperature which must be minimised to ensure the bacteria cannot begin again to multiply in the food.

Symptoms of illness include abdominal pain and diarrhoea and may begin 6-24 hours after the food is eaten and last 12-24 hours.

Clostridium botulinum

This bacteria is another member of the clostridium family but is much more dangerous. This one releases its particularly poisonous toxin in the food if it is allowed to begin multiplying again at room temperature after surviving cooking by forming spores. As it is commonly found in soils, foods likely to be affected are those which have come in contact with the soil - vegetables and filter feeding shellfish. It has been previously associated with incorrectly preserved meats, seafood and vegetables.

Symptoms of illness include diarrhoea, then vision, breathing and speech difficulties. Fatigue, dizziness, double vision and paralysis may result with death within 1-8 days likely unless the antitoxin is given. This is one of the most toxic toxins on the planet - only a very small amount is needed to cause life threatening illness. Symptoms are likely to appear 24 - 72 hours after the food is eaten. Again it is the time at room temperature which allows the toxins to be produced. Also, growth can be prevented by ensuring the preserves are sugary, salty or acidic enough (see later under high risk and low risk foods).

Staphylococcus aureas

This bacteria can only get into the food from unsafe handling by the food preparer. It is commonly found in the nose, throat and sinuses of humans and in pimples, boils, and infected cuts and burns of the skin. It gets into the food from sneezing, coughing, dribbling or unwashed hands and skin. It then releases its toxin as it multiplies in the food at room temperature.

Symptoms of illness include severe vomiting, abdominal pain, diarrhoea and collapse; usually starting 2 - 6 hours after eating the food and lasting for 6-24 hours.

Bacillus cereus

This bacteria is another spore forming bacteria that releases its toxin into the food as it multiplies at room temperature. It is commonly found in soils and dusts, thus the most likely foods affected are rice, grains, vegetables and reheated meat dishes. Again, prevention is simply a matter of ensuring that if the food is not to be eaten straight after cooking, it is either kept hot at over 65°c or cooled down rapidly and chilled at below 4O°c until eaten or thoroughly reheated to over 80°c.

Symptoms of illness include vomiting for 1 - 5 hours and / or diarrhoea for 6 - 15 hours, likely to start 1 - 15 hours after eating the food and lasting 1 - 2 days.

Yersinia

Yersinia is a non-spore forming bacteria which causes illness merely by its presence, similar to salmonella and campylobacter. It is commonly found in meats, seafood and water. Prevention is mostly a matter of personal hygiene of the food preparer and prevention of cross-contamination between food types.

Symptoms of illness include watery diarrhoea, intense abdominal pain, headaches, fever and vomiting. Illness is likely to begin between 24 and 36 hours after consuming the food or water, and last or 1 - 3 days.

E.coli

Escherischia coli is also a non-spore forming and non toxin producing opportunistic bacteria. It is commonly found in the gut, but if it gets into food causes a food infection illness. There are many different types of E. coli, causing slightly different symptoms, but they are typically of a vomiting and diarrhoea with abdominal cramps type illness. Prevention is mainly by control of personal hygiene of the handler and cross-contamination between food types. It is most commonly found in meats – especially highly processed selections, fish, vegetables and dairy products.

Symptoms are likely to begin around 18 hours after consumption of the contaminated food and last for an average of 2 days, longer for some of the nastier versions of the bacteria.

These illnesses can kill. In severe cases, especially in children, the elderly or immunocompromised, death by dehydration can occur. There is no excuse for illness caused by these bacteria. The required preventative measures include:

  • Thorough cooking properly thawed food to at least 80°c
  • Minimising time at room temperature (to less than ½ -1 hour) before putting the food in a chiller, if not being eaten immediately or kept hot until it is.
  • Not handling food if you are ill with a cold, 'flu or any vomiting or diarrhoea
  • Washing hands thoroughly and frequently (see the personal hygiene section later for details).
  • Washing and sanitising all utensils and equipment according to the risk of the food being prepared (see cleaning section later for details).
  • Preventing cross-contamination between food types
  • Pest control
  • Wash fruit and vegetables before using them
  • Once preserved foods have been opened, keep them in the fridge

Giardia

Giardia (pronounced gee-ah-dee-ah) is a parasite found in the gut of humans and animals such as cattle, sheep, cats, dogs, rats and possums.

It is passed on in the faeces of infected animals and humans. Giardia is widespread in New Zealand and the parasites can live in the environment for long periods, especially in lake, river, stream and roof water.

People become infected when they swallow the parasites. This may be from contaminated water and food, or from contact with infected animals or humans.

Cryptosporidium

Cryptosporidium (pronounced crip-toe-spor-idium) is a parasite found in the gut of birds fish, reptiles (eg geckos and turtles), humans and animals such as cattle, sheep, cats and dogs.

It is passed on in the faeces of infected birds, animals and humans. Cryptosporidium is widespread in New Zealand and the parasites can live in the environment for long periods, especially in lake, river, stream and roof water.

People become infected when they swallow the parasites. This may be from contaminated water and food, or from contact with infected animals or humans.

Cleanliness


Cleaning involves three types of energy:

  • Physical - That's you scrubbing and wiping. There is no getting away from it, cleaning requires effort. The more you put in the greater the effect you achieve. If you don't like cleaning, work harder. That way the cleaning will be done better and quicker.
  • Thermal - that's heat. Mostly it will be hot water, but in the case of a drier cycle it will also include hot air. Make the heat work for you, it has some kill power by itself. The hotter the water the faster the cleaning or the more efficient the sanitising. Wear some strong rubber gloves to protect yourself and allow the heat to help you clean.
  • Chemical - that's what does the main part of the work. In theory you can do all the cleaning you need with hard work and baking soda, but using other specially designed chemicals will make the work easier and more effective. The term cleaning really means a number of different things. So, there are different chemicals available to help you do those different aspects of cleaning as effectively and efficiently as possible.

Detergents or degreasers

Detergents and degreasers (sometimes called surfactants) clean. They work best in a hot water solution. These are your soaps, dishwashing liquids and anything 'sudsy'. Once your suds have popped and the water is cold and grey you are wasting your time trying to clean anything with it. Get a fresh bucket. Detergents and degreasers remove dirt and grease to obtain a "squeaky clean" surface that supposedly cannot support bacterial life. But they cannot actually kill anything. Because at the microscopic level surfaces aren't really as smooth as they seem to us, high risk surfaces need to be sanitised as well.

Disinfectants or sanitisers

Disinfectants and sanitisers do have some kill power but they don't work on an unclean surface. A surface to be sanitised must have been cleaned first. There are different kinds of sanitiser to recognise. These are products like phenols, like the old lysol soaps; alcohols, such as methylated spirits or isopropyl alcohol; or chlorine products. Ammonia products are really heavy duty cleaners, but they do have some kill power if allowed a contact time to do this. You need to know the products you use to ensure you use them correctly and that you get your money's worth out of them. Firstly, read the label to confirm that the product is a cleaner or a sanitiser.

Secondly, read the label to confirm whether it is likely to give an instant kill effect or it needs contact time to do its job. Chlorine products like bleach will have instant kill effect and can be used concentrated or diluted in a bucket or spray bottle - just read the instructions on the container.

Some other products may call themselves a cleaner and sanitiser. If they do, this probably means they are more likely to be an ammonia type product, not a straight out chlorine, and therefore require contact time to have any kill power. These products are also not likely to kill viruses, whereas a chlorine product will. Most of the "spray and wipe" products are like this. When you simply spray and wipe, you are cleaning. If you spray, wait and wipe, you are much more likely to be sanitising (assuming you cleaned first of course).

It is also important to use the right dilution strengths. Many people just pour a random number of gurgles into the bucket and add some hot water until it is too heavy to lift. You may be wasting money by putting too much in the bucket or you may be wasting your own time and effort by not putting in enough.

Make the chemical you use work properly for you.

Sterilising

A steriliser will kill all microbial life, but these tend to be used in the medical surgical fields, not the food environment. Food isn't sterile, nor are we. We don't need to try and make the food environment sterile, just sanitised to control the harmful pathogens. If we killed off every bacteria, there would be no bacterial defence against pathogens to help us out.

Which surfaces to clean, and which to sanitise

The best cleaning is done by a combination of physical, thermal and chemical energy by way of cleansing with a detergent, then disinfecting or sanitising. In a food premise, all surfaces, equipment, utensils, appliances and service items must be taken into consideration.

For instance: floors, walls, ceilings, cupboards, shelves and benches will be cleaned with a detergent. But particular attention to sanitising as well as cleaning would be made to food preparation surfaces, fridges and freezers, appliances, chopping boards, dishes, glassware and utensils. Often this will be done with heat from the dishwasher. Ensure your dishwasher provides a 10 second rinse cycle of at least 80°c. This requires a commercial appliance.

The oven is also likely to keep itself safe with heat. Well designed premises and equipment with continuously smooth, impervious to water and lightly coloured surfaces makes the job a lot easier.

But don't just think of food preparation surfaces. Remember also to sanitise surfaces that are frequently handled by food preparers. Surfaces such as the fridge and freezer handles, light switches, taps, cupboard and drawer handles, ingredients containers e.t.c. There is no point carefully washing your hands if then every thing you touch is contaminated with food goop.

Also don't forget items such as salt and pepper shakers, vases, the outside of dusty wine bottles and other things that might not get regularly cleaned.

Any item, that by its level of damage can't be properly cleaned, such as cracked crockery or cutting boards, must be thrown out. If a surface can't be cleaned easily, then it must be cleaned with difficulty. Either way - a safe environment must be provided.

Cleaning Equipment

The other important things to keep clean and sanitised are your cleaning tools. You can't sanitise a food bench with a cloth that is crawling with the bacteria you wiped off the floor a while ago and you can't safely dry your hands on a towel that is crawling with bacteria left there from another staff member before lunch.

Cloths and sponges must be numerous enough that you always have plenty of fresh dry ones at hand should one become unclean with risky juices such as from raw meat. Soak them in a sanitising solution before they are washed, put them through a hot wash and dry then in a hot air drier or in the sun. rinsing is not enough.

Buckets and mops must also be washed out with a hot sanitising solution after each use and allowed to dry in between uses.

If anything is allowed to sit around soggy, you can guarantee it will be multiplying bacteria at the same time.

How to clean?

Although you may think you know how to clean already, this section is designed to set out the ideal cleaning method to raise your awareness of what you are doing so that every time you clean anything it is done with maximum effectiveness and efficiency. There is no point wiping something that should have been scrubbed and there is no point doing the most important job of a food business ineffectively. You have to do it so you might as well do it well.

  • Firstly, remove any matter that doesn't need cleaning, such as scraping plates, picking up spills and 'droppings'
  • Rinse to remove any other residue.
  • Next, wash and scrub in a hot soapy water to degrease and remove dirt. If the surface is a high risk one, you then sanitise with a hot sanitising solution and rinse in hot water.
  • It is best if possible to allow the surface to air dry to prevent re-contamination, but if there is neither time or space for this ensure that the cloth used to dry the surface is a fresh clean one that will not simply wipe back on a bacterial loading from previous wiping of another surface.
  • Finally, if the surface is a mobile item, put it away in a clean storage area. That is, not a sticky shelf or a drawer filled with crumbs or somewhere where flies are going to come and poo on it.

If a piece of equipment can be broken down into parts, do so and clean each part separately. Parts with direct food contact must also be sanitised.

Make sure you don't leave cleaning product residue behind on high risk surfaces or you may have swapped a microbial contaminant for a chemical one. Always rinse off afterwards with a hot water solution and a clean cloth.

Cleaning Programmes

Cleaning practices must be thorough, stringent, regular and monitored. A written cleaning programme allows each person responsible to know exactly their duty, how to do it, when to do it and it acknowledges a job well done or whether something needs to change. A supervisor using a written cleaning programme to monitor cleaning can tell if a problem is due to a lack of effort, the wrong cleaning frequency or method or if a different product may be necessary.

An effective and efficient cleaning programme removes attraction to bacteria and pests, allows sanitation to provide a safe and wholesome food is produced and ensures a safe and pleasant work environment for you and your colleagues.

The plan should list each item or surface to be cleaned, the product and method to be used, the frequency with which it should be cleaned, who is responsible, an indication that it has been done and an indication that it has been checked. Make the "what to clean" list as detailed as possible, then less things will be forgotten. If you laminate your cleaning programmes, with the right felt pen you can use it like a white board and reuse it each week or shift. See example below, but remember you need to make your programme apply to your premise, staff numbers and food preparation types. It may vary considerably from this one.

Surface /item Product used Method used Frequency Person responsible When done Checked by
Floors Cleaner Mop Daily      
Walls Cleaner Wiipe Weekly      
Ceilings Cleaner Wipe Monthly      
Appliances, utensils, crockery   Dishwasher As used      
Benches, boards & shelves Cleaner then sanitiser Scrub Each time used      
Cupboards & drawers Cleaner then sanitiser Wipe Weekly      
Fridges & freezers Cleaner then sanitiser Wipe Weekly      
Display cabinets & containers Cleaner then sanitiser Wipe Daily      
Handles, Switches & taps Cleaner then sanitiser Scrub Daily or when soiled      
Toilet & Bathroom.   Wipe Weekly      
Flue     Three monthly      
Vent hood filters     Fortnightly      
Grease trap     Three monthly      
Rubbish bins Cleaner scrub Daily      

Good Practices


Contamination of food can be controlled by maintaining good food hygiene and house keeping practices. High standards of food hygiene minimise food spoilage and contamination and help to ensure that when food is eaten it is as wholesome and free of pathogens as possible.

Good housekeeping practices are essential to ensuring the premise are safe to prepare food in, both for the food and the food handlers. It is the maintenance of a clean and tidy workplace.

Good housekeeping:

  • Is maintenance of a clean and tidy workplace
  • Promotes wholesome and safe food
  • Encourages economy
  • Implies safe working practices

 These aspects of house keeping are all reliant on efficient and effective cleaning practices which consider;

  • Physical
  • Chemical
  • Biological aspects of Premises, storage, ingredients, handling, display, preparation, cooking, serving and disposal of food.

 This is done by:

  • Prevention of unhygienic situations - pest control & refuse storage
  • Cleaning practices - cleansing, sanitising, prevention of cross contamination, and re-contamination
  • Personal hygiene - ensuring the food handler doesn't provide the risk

The Premises Itself

A major part of food safety and good housekeeping practices is the premise itself. According to the Food hygiene Regulations and the Building Code, this is required to be designed in such a way as to facilitate safe food preparation and a safe working environment. Any food preparation, storage or display area must come up to the required standard before it can be licensed to sell or supply food.

Essentially all surfaces should be continuously smooth, impervious to water, clean, readily cleanable, resistant to wear and of a light colour.

  • Floors - Floors are also required to be resistant to wear and covered to the walls and permanent fixtures.
  • Ventilation - There must be adequate ventilation to remove odours, smokes, moisture and to provide a comfortable environment that doesn't attract pests.
  • Lighting - Lighting must be adequate to allow safe work and so that labels can be clearly read and dirt can be seen and cleaned up.
  • Staff Changing Room - There must be a staff changing room so that fresh clothes can be put on in which to prepare food and outside clothes are not left in the food preparation or storage areas.
  • Wash Hand Basins - There must be wash hand basins provided convenient to the food preparation areas and the toilets, and these must be provided with hot and cold running water, soap, a nail brush and some sort of hand drying device. Disposable paper towels are often thought to be the best option for this as they prevent recontamination of hands.
  • Toilet - Toilet and hand washing areas must also be maintained in a clean state and kept stocked up with their required supplies.
  • Grease Trap - If you have a grease trap it must be regularly cleaned out to prevent odours and attraction to pests.
  • Smoking - Smoking must not be allowed in any part of a food preparation, storage or display area.
  • Dogs - Only registered companion dogs are allowed in any food premises. (Believe it or not, cats are allowed for rodent control purposes as long as they are not providing any source of contamination - this obviously means keep them outside!).
  • Refuse - Refuse must be collected in a lidded container which is cleaned out after each emptying. It must not be allowed to smell or attract pests. Putrescible (rotting) refuse must be removed from the premises each day or stored in a chiller (clearly marked!) until collected.

Grease Traps

Food, oil and grease (FOG) treatment for food premises connected to the sewerage system

Regulation: If a building is likely to convey FOG in wastewater, it must have a grease trap or similar, to maintain sanitary conditions. The purpose of the grease trap is to prevent FOG from getting into the sewerage system. All food premises' sanitary fixtures shall direct their waste through their grease trap.

Grease traps are important in Central Hawke's Bay because:

  • When FOG is washed down the drain it frequently sets in the sewage line when it cools. Blockages result in significant costs to the Central Hawke's Bay District Council and therefore the ratepayers.
  • High levels of FOG inhibit the effectiveness of sewage treatment. It is therefore important that levels of FOG are controlled to ensure that our treatment systems are efficient and that the corresponding discharges are not harmful to their receiving environments.

No food premises should put FOG down the sewer. Solid food wastes can be disposed of via the refuse collection or composted. Waste disposal units are not recommended. Liquid or solid fats can be recycled through tallow melters. But anything that goes into the sewer, i.e. gets washed down the sink, should go through a grease trap first.

Selection of a trap

There are a number of designs of FOG traps available and in use within the food industry. The type selected will depend upon each premises' circumstances in regard to amount of FOG disposed of, number of meals, cost and space available.

Minimum dimensions for a food premises' grease trap is an allowance of at least 5 Litres per seat, plus an extra 25% to allow for peak flushes:

Number of seats Without dishwasher or waste disposal With dishwasher or waste disposal
Up to 50 350 L 455 L
Up to 100 625 L 600 L
Up to 150 975 L 1200 L
Up toi 250 1575 L 2700 L

Waste disposal units and dishwashers must be connected before the grease trap so that their discharges are also dealt with. Note the extra capacity needed for these.

A conventional grease trap basically allows the wastewater to settle so that FOG can rise to the top of the solution and set, leaving the remaining water to flow on down the sewer. When the FOG layer is allowed to get too deep it can block the water outlet and cause dysfunction. If clearing the FOG layer is left too long it will also turn rancid and cause increased foul odours and attraction to pests.

Inspection points are available for checking if the FOG layer is thick enough to warrant clearing. When this is so, the whole lid can be removed to lift off the FOG layer and dispose of it at the tip. (trade waste cannot be collected via refuse collection) Alternatively, a registered 'sump sucker' can take it away for you.

Alternatives to conventional grease traps

An enzyme grease converter: A completely sealed unit that is capable of being installed inside. It is advisable not to connect waste disposal units and dishwashers into these as they will clog quickly due to their smaller size, and chemicals will kill off the enzymes. They require regular dosing with enzyme powder to allow microbiological activity to work at low flow times.

Automatic interceptors: A sealed unit capable of being installed inside. These are a mechanical device that periodically warms the trapped solution and skims off the FOG layer into a separate container for disposal at the tip. These units are smaller and may fit under bench units.

Summary

First, you need to identify whether there already is a grease trap on your premises site and what type it is. Look for lift out concrete slabs in the yard of your premises. If you discover one you didn't know about, chances are it needs cleaning out urgently!

The next trick is to find manufacturers specifications for cleaning it. If this is not possible, call a 'sump cleaner' to do this for you. Look under Waste Disposal or Tank Cleaners in the Yellow Pages.

A conventional grease trap, once under control again, should need checking at least monthly. If the FOG layer is thick, it's time to clean it out again. This frequency will vary between traps and premises depending on the volume of the trap and the amount of FOG put down it.

Food Hygiene Regulations 1974


Any premise used for the manufacture, preparation, packing, storage or sale of food to the general public must be registered with the Local Authority. That is, the City or District Council

Therefore:

  • premises used by the Crown or Local Authority,
  • partially exempted premises; where the provision of food is secondary to the main purpose of the premise, such as hospitals, retirement homes, schools or work cafeterias,
  • occasional food premises such as church halls, market stalls and sausage sizzles,
  • and any premise not open to the general public such as some clubs, do not require registration

Before any premise requiring registration can open for business they must be inspected by an Environmental Health Officer to ensure that the premise construction complies with the Food Hygiene Regulations and any relevant Bylaws, and the registration fee must be paid for the Certificate of Registration to be issued.

Opening Inspection will include:

  • Construction of physical aspects - floors, walls, ceilings, lighting, ventilation, space, changing facilities, toilet accommodation, wand hand basins, water supply, sewage disposal and yards.
  • Notices to be displayed
  • First aid facilities
  • Cleaning and maintenance of the premises - facilities, equipment and programmes
  • Restricted use of rooms to protect food from contamination
  • Pest control measures
  • General duties of the occupier
  • Equipment - condition, sufficiency and appropriateness of type for maintenance and cleaning.

Once open, registration is required to be renewed each year, or when the business changes ownership. Regular inspections by the Environmental Health Officer can also be expected, regarding the above matters as well as:

  • Conduct of workers - food handling, food protection, clothing and behaviour of workers and food vehicles
  • Pest control practices
  • Cleaning programmes
  • Staff training
  • Requirements specific to certain types of premises - bakeries, delicatessens, eating houses, meat and fish sales, milk and yoghurt sales, ice-cream and frozen confections, food vending machines, breweries, wineries and sale of liquor hygiene aspects.

From July 1997, an amendment to the Food Act 1981 brought in an alternative to Registration with the Local Authority. Food businesses can choose to apply for exemptions from the requirements of the Food Hygiene Regulations and register a Food Safety Programme with the NZ Food Safety Authority instead.

This Programme must be based on a system of Hazard Analysis and Critical Control Points - HACCP, which ensures that each stage along the food production process is examined to identify potential hazards, the risk involved, how they may be controlled, which controls are the most vital and how they are ensured to be working to provide safe food. Training in food safety is obviously a vital part of food safety programme development and implementation.

This course will give you a basic level of food safety training suitable for any food handler in the food industry. If you become a food business owner or manager, or are just keen, further training in HACCP and Food Safety Programme development is also available.

Registration of Food Premises

In order for a food premises to be registered with a local authority, it needs to meet the conditions of the First Schedule of the Food Hygiene Regulations, 1974.

This summarises the requirements of the Food Hygiene Requirements 1974 that apply to your premises. It is not intended to be a substitute for the requirements of the Food Hygiene Regulations 1974 but it has been prepared to clarify the expectations of the Napier City Council for compliance before the premises can be registered. Refer to the Food Hygiene Regulations 1974 for the full details of these requirements.

General

  • The premises shall be well constructed and in good repair. As far as possible, they should offer no entrance or harbourage to vermin.
  • Materials used in a food premises must be of high quality and may be expensive, but will help to prevent dampness, peeling wall surfaces, cracked floors and contamination of food areas. Repairs to substandard premises are costly and can result in the premises being closed.

Floors

  • The floor should be suitable for the particular task. This is important to assess as in some processes floors are subjected to considerable wear and tear. Good quality floors, durable, waterproof, and maintained in a good condition and state of repair are easy to clean and to keep clean.
  • In wet processing areas, impervious and graded floors will permit rapid disposal of liquid waste. In areas which are swept or mopped there is no need for grading.
  • Floors should be coved up to a height of 75mm at the walls to facilitate cleaning. Pencil coving is not appropriate.

Walls

  • The main criteria are that walls are light coloured, smooth, non-absorbent and are easily cleaned. The minimum height from floor to ceiling is 2.4m.
  • Cooking areas - need to be heat resistant, e.g. stainless steel and aluminium sheet between cooking equipment and vent hood. The joints should be filled so that no gaps are evident.
  • Wash Up Areas - Walls surrounding sinks and wash hand basins, dishwashers and glass washers are to be plastic laminated sheeting (or alternative approved surface), 2m from the floor level.
  • Storage Areas - Gloss painted or polyurethaned, stopped and finished Gibb or equivalent, or medium density fibre board.

 Ceilings

  • Generally, the same requirements as for walls with a smooth, impervious and dust proof finish being important, so as to permit effective cleaning.
  • Any exposed trusses or beams need to be completely enclosed.

 Lighting

  • The illumination of the premises shall be of sufficient intensity to enable effective inspection and cleaning of all areas of the premises. Lights should be either fitted flush to the ceiling, or otherwise designed and placed for ease of cleaning.

 Ventilation

  • Ventilation must be sufficient to maintain comfortable conditions for people on the premises by preventing air from becoming excessively heated, preventing condensation and excess moisture on floors, walls and ceilings, and removing objectionable odours, fumes and impurities.
  • Suitable ventilation is to be provided over all cooking equipment.
  • The system is to comprise a hood enclosure, fan of sufficient capacity, grease filters, condensate channels and ducting to remove cooking vapours to the exterior of the premises. The extractor system is to discharge in a manner that will not create a nuisance and it to be constructed of durable materials which will facilitate cleaning.
  • There are to be no discharges to the air that are noxious, dangerous, offensive or objectionable at or beyond the boundary of the food premises property. Theses discharges include odour and dust. To avoid a nuisance situation, the ventilation system discharge point is to be situated at the buildings highest point, in an area removed from opening windows and air intake points.
  • The system is to comply with noise levels set out in the District Plan.

 Space

  • Adequate unobstructed floor space for workers is essential as it promotes efficiency and makes for easier cleaning. As a general guide, and where it is not specified by regulation, it is recommended that the space per person is not less than 3m², or a minimum of 9.5 m², whichever is greater. This space is for food preparation, cooking and cleaning of food utensils and is to be clear of furniture fittings and stored goods.

 Changing Facilities

  • Clothing worn by food workers should not contaminate the food, and so it is necessary to separate street clothing from food processing or retail areas.
  • Larger premises should have locker rooms for storing all of the outdoor clothing, shoes and bags of the workers. Smaller premises should still have specific areas set aside for storage away from food areas.

 Toilet Accommodation

  • Toilets should be conveniently placed for the food handlers, and designed to protect the food from any possible air borne contaminants. The building code requirements for the number and design of toilets should be referred to (Talk to the Bulding Inspectors).
  • Toilets and isolation chambers should not be used for storage.

 Wash Hand Basins

  • Wash hand basins are required in each bar and kitchen area and should be supplied with soap, nail brush and suitable hand drying facilities (e.g. disposable paper towels).
  • Handwashing facilities are essential to the personal cleanliness of food workers. It is important that all food workers wash their hands after using the toilet, before commencing work and at periodical times during the day.
  • Hand basins must be used for handwashing only. They should be located so that supervisors can observe that workers frequently wash their hands, and it is desirable that the facilities are located as close to the work area as possible. As a guide it is recommended that they be not more than 6 metres from the work area, although it is recognised that this is not always possible.

 Sinks

  • Preparation Sink - for washing food, connected directly to waste.
  • Dishwash sink - for washing dishes, connected to grease trap.
  • Cleaners sink - for emptying/filling buckets used to clean large appliances, floors and toilets.
  • All sinks must have a continuous supply of piped hot water the entire time the premises is used.
  • The minimum water temperature is 63°c for all sink units and 83°c for dishwashing units.
  • All plumbing should be installed by registered tradesmen and comply with the requirements of the building code and relevant local authority bylaws

 Water Supply

  • The water shall be of a potable quality and wherever possible it should be from a local authority approved reticulated supply.

 Hot Water Supply

  • The hot water supply must be of an adequate volume and temperature to cope with the maximum demands of the premises. If there is insufficient hot water, there is a tendency to use less than is desirable. It is difficult to establish a formula which is suitable for all premises. However, a suggested minimum for eating houses is a storage capacity of 180 litres.

 Grease Trap

  • A grease trap or other suitable grease pre-treatment facility. Of sufficient capacity, is required of there is a likelihood of grease from your operation entering the sewer.
  • The grease trap just be cleaned or treated so that no nuisance is caused (Health Act 1956, S29)
  • Dishwashers must not be installed so as to discharge through the grease trap.
  • Always refer to the manufacturers instructions on maintenance etc.

 Pest Control

  • Fly screening of all windows and entrances, self closing doors, properly directed air currents or other suitable control measures are required to keep to birds and flies.
  • All joints with plumbing or other fittings must be sealed to prevent to prevent entrance or harbourage for rodents.

 Yard

  • The yard area is important as refuse is usually stored here and food stuffs enter (and occasionally leave) via the yard. Provide suitable washable bins fitted with close fitting lids for both inside the kitchen and any awaiting collection.
  • By being paved, graded and drained, the yard can be kept clean and it is essential that the surrounds of any grease trap are impervious.

 Cleaning Chemicals

  • A suitable area for the storage of cleaning chemicals and cleaning equipments s to be provided at each site to avoid contamination of food.

Personal Hygiene

Humans may well be the most dangerous pest in the food preparation and storage areas. As with the rest of the environment, we carry bacteria and viruses around on our bodies that if not controlled can get into food and cause illness. This is especially so in the case of opportunistic pathogens that may be harmless or even beneficial on us but disease causing if they get back into food and are consumed, or if they produce toxins in the food.

To prevent being the source of food borne illness or contamination, follow the following personal hygiene rules:

Always wash your hands:

  • Before beginning to prepare food
  • After handling rubbish
  • After going to the bathroom
  • After smoking
  • After touching or scratching your hair or skinIn between high risk and low risk foods
  • After handling cleaning or pest control chemicals
  • After blowing your nose, coughing or sneezing
  • After licking your fingers
  • Whenever your hands become obviously dirty
  • After handling money

 When washing your hands, use warm water and lather your hands all over with soap. Ensure you vigorously rub all surfaces of your hands, fingers and wrists - back and front and in between fingers. This should take at least 10 seconds. Time yourself next time you wash your hands. Holding your fingers under a trickle of cold water for a few seconds is not washing your hands!

You also need to pay particular attention to your nails. These should be kept short and clean with no nail polish and must be scrubbed with a nailbrush when the hands are washed.

Keep your hands out of your pockets and away from your nose. Use disposable tissues rather than a handkerchief if you have a runny nose. Then wash your hands of course!

Jewellery

Jewellery must not be worn on the hands or wrists to facilitate proper hand washing and to prevent the jewellery becoming a source of cross contamination when gunk is transferred from one food to another via the jewellery.

Gloves

If you have a flaky or wet skin condition or are wearing a wound dressing of some sort it may be advisable to wear gloves. However, these are easily abused and must be worn with care. You may feel nice and clean inside your glove but that doesn't mean that you are protecting the food from whatever you just touched. Hands must be washed before the glove is put on and either washed or the gloves changed with the same frequency as the hand washing list above.

Remember, the outside surface of the glove is no cleaner than your hand would have been if you weren't wearing the glove.

Illness

You must not prepare or serve food if you are ill with a cold or 'flu where you are dribbly, sneezy or coughing as these 'productions' are a great source of bacteria, especially Staph. aureus.

You must also not prepare or serve food if you are ill with any sort of vomiting or diarrhoea, unless it is confirmed by your doctor to be caused by a non-microbial reason (such as pregnancy or irritable bowel syndrome). If you do get ill with vomiting or diarrhoea, you should see your doctor and have a faeces sample sent away for analysis to determine which bacteria or virus is causing your illness. This will then decree how long you must wait before returning to food handling.

Many food borne microbial illnesses are notifiable. This means that the lab or your doctor will notify the local Community Health team so that they can trace the source of the illness to ensure no risk to the general public. You may be contacted by them to ensure you are following the correct procedures and staying away from work, or in a safe alternative job while you are at risk.

Clothes

Freshly cleaned clothes should be worn each day. You may even need to keep a spare outfit at work if you are likely to get really dirty during the day. These clothes should be put on at work not worn from home, to ensure you don't bring dog hairs, road dust and other 'outside' contamination into the food preparation area. Don't wear fluffy clothes that could shed into food. Be sure you are comfortable so that you don't get sweaty or itchy and need to touch yourself.

The level of clothing protection depends upon the level and type of food preparation. Some places need to wear a full covering uniform, others an apron will suffice. Just make sure what you wear is right for the job. Remember you are protecting the food from you, not you from the food.

Hair

Hair is required to be "adequately restrained" when preparing or serving food to ensure it cannot be a source of contamination (even clean hair will gross out any customer). This is something that is commonly ignored in food premises and hair complaints are common. It is not just a matter of tying back long hair, short hairs fall out too. Whatever method you choose must be used thoughtfully. A trendy baseball cap sits on your head and itches, it doesn't actually restrain anything, especially with the pretty curls left hanging down the sides.

Mouth

The mouth and teeth can be a good source of bacteria which may be then breathed over food or food preparation surfaces. Keep you teeth healthy and clean. Don't bite your nails or lick your fingers, don't cough or sneeze over food and don't smoke in a food area or before handling food without washing your hands.

First Aid

You are required to have a first-aid kit in all food premises. If someone sustains a wound at work, ensure the wound is properly cleaned and dressed and remains covered until healed. Someone with an infected or suppurating wound on the hands or wrists should not handle food. Ensure any surface on which blood has been spilt is cleaned and sanitised with a chlorine solution. Throw away any food contaminated with human blood.

The trick with personal hygiene measures is to remember why you are doing them: to stop yourself being a source of contamination, cross-contamination or recontamination to the food you are handling.

  • Wash your hands,
  • Wear a clean uniform that has been put on at work
  • Only taste food with a clean spoon, not your fingers
  • Don't wear jewelleryKeep your body and mouth clean
  • Keep your hair restrained
  • Don't handle food when unwell
  • Don't touch, scratch or itch yourself
  • Cover wounds with a firm, waterproof dressing
  • Work in an environment that doesn't make you sweaty
  • Use 'hands off' methods of food service whenever possible

Food Preparation

If food has been frozen, ensure it is completely thawed before it is cooked. Otherwise it will not receive the actual time and temperature ratio you thought it did, some of that time will have been spent thawing out, not cooking. However, some foods may come with cook straight from frozen instructions - this is fine as extra time has been included. Follow the instructions and probe the food, when finished, to confirm it has reached the right temperature for kill off of bacteria, which is 80°c.

In preparing foods, raw foods must be kept separate from cooked or ready to eat foods to prevent cross-contamination between the different food risk types. You must either:

  • Clean and sanitise your hands, cutting boards, knives, slicing machines and any other utensils in between different food types, OR
  • Have separate boards and utensils for different food risk types, OR
  • Prepare the low risk types before the high risk types to ensure no transfer of juices from one food to another.
  • If you taste food while preparing it, ensure a clean spoon is used each time to prevent cross- contamination.

Thawing


Thawing must be done either quickly in a microwave or slowly in a fridge or chiller. Again, the time at room temperature must be minimised to prevent bacterial growth. If a microwave is not appropriate for that food type, you are simply going to have to get more organised to allow the time it will take to thaw the food in the fridge or chiller. Some foods can be thawed under running cold water, but it depends on whether this waterlogs the flesh or not.

Do not refreeze thawed foods. If they been thawed accidentally they must be eaten straight away or cooked and then refrozen if need be.

Cooking

Cooking times and temperatures must be sufficient to ensure that all bacteria and their toxins are destroyed. If they are not, re-increase of multiplication may occur during cooling or incorrect storage of cooked food.

Food must be thoroughly cooked right through. Preheat the oven so that the food had the correct temperature right through the cooking time and probe the food once you think it is ready to ensure it has reached the correct temperature. Juices should run clear, any joints should move freely and it should be piping hot. This is especially important if the food has been cooked in a microwave as you cannot determine what temperature it operated at.

To probe for food temperature ensure you sanitise the probe first and insert it into the deepest part of the food. It is best to check a number of different sites. In poultry, check the thigh joint, not the abdomen as this may be hollow, and you're looking for the meat temperature not that of the stuffing.

You also need to check your thermometers against each other to ensure they are accurate. It is best to get a reliable thermometer that can be calibrated. Your whole business hangs on your thermometers' accuracy.

Microwaves

When using a microwave, ensure you turn or stir the food for even cooking, allow the standing time at the end to finish the process, and check it before it is served to ensure the cooking has been even and thorough. If using a microwave it is best to follow microwave specific recipes, as microwaves are easily misused with resulting unsafe food.

Serving & Displaying

Foods should be prepared as close to serving as possible to prevent the risk of recontamination. If foods are prepared and reheated, special care must be taken with the in between hot and cold time frames and prevention of contamination.

Hot Foods

If not eaten immediately but put on display, safe temperatures must still be maintained. Hot foods on display must be heated to 80°c before being put into the display case, which must keep the food at over 65°c. This must not be for longer than one day on display.

Cold Foods

Cold perishable foods on display must be at less than 4°c or not out for longer than 2 hours before being disposed of as unsafe to eat. Many people spend lots of money of chilled display cases that are not designed to act as fridges and leave perishable foods in them all day at temperatures like 10 - 20°c. This could be really dangerous and is an offence under the Food Hygiene Regulations 1974.

It doesn't matter whether you use time or temperature to protect you food, but one of them must be used. Know what temperatures your display cases provide by checking them with a thermometer. Then you can assess how long you may display perishable foods in them. If they are not cold enough for all day display, keep a small amount on display and stock them up from the fridge (which you have already confirmed to provide less than 4°c!)

Lower Risk Foods

Some foods, which aren't readily perishable, such as sweet muffins and cakes, fruit, vegetable dishes, may not need chilled display. But all foods on display must still be covered and protected from contamination.

Ensure foods on display do not touch each other if they are of a different risk type. Do not allow the bottoms of containers to touch other foods and ensure serving utensils are readily available for each dish to prevent cross-contamination by them. In self-serve situations, your customers may have to be supervised to ensure they provide no risk to the foods by misuse of utensils or contamination by poor handling and sneezing and such like.

During preparation and especially once food has finished being prepared, handle the food directly as little as possible. Use clean utensils, tongs, scoops and the like, but make sure these aren't a source of cross- contamination between foods.

Left-Overs

Left-overs must be thoroughly reheated to piping hot, but only once. Do not make left-overs out of reconstituted left-overs. The time/temperature ratio will have been tested too many times to guarantee safety. If left-overs are to be eaten cold, it should be within three days, assuming they were kept in a fridge at less than 4°c for that time and well protected from contamination.

Food Storage


Inspect supplies on arrival for damaged packaging, thawed frozen foods, insect or rodent damage or other contamination and the coldness of refrigerated foods. Ensure food is stored quickly and in the correct area.

Non-perishable foods such as cans, unopened bottles and dry foods are alright to be stored at room temperature in a cupboard or pantry. Packets are best in sealed, airtight containers with labels so that they last longer and pests cannot get at them. Dry goods storage should be dry, cool and well ventilated. It must be cleaned regularly as the rest of the premise and ensured to be pest free. Food should be stored above the floor to facilitate cleaning. Foods should be organised to ensure stock rotation. That is, first in, first out. Keep an eye on use-by dates. It is best to keep stocks to a minimum and buy fresh frequently.

Perishable foods such as meat, dairy foods, eggs, wet foods, vegetables and left-overs need to be kept in the fridge or freezer depending on the required storage time. They should also be covered and easy to identify. Raw foods should be stored below cooked foods and not touching or dripping on each other. Again stock rotation must be ensured and some foods will require date marking to ensure they are not left too long.

Time and Temperature


Fridges are required to ensure the food is stored at less than 4°c.
 A walk in chiller for meat or fish should ensure the food is stored at less than 2°c.

Note my specific wording regarding temperatures. I don't just mean the fridge should be set to operate at less than 4°c, you must ensure that whatever the fridge is set at the actual food is at less than 4°c, by checking it with a mobile thermometer, not just checking the dial of the fridge. There is often a vast difference in temperatures throughout appliances, and the dial may not accurately represent what is actually going on at different places inside.

Readily perishable foods should not be kept in a fridge longer than about three days. Less perishable foods like vegetables will last longer, but their nutritional value and appeal will diminish. Fresh is always best, for appeal, wholesomeness and safety.

If protected from freezer burn by wrapping they should last much longer in a properly used freezer.

Freezers must ensure the food is at less than -18°c. Just because it is frozen solid does not mean it is safely stored. At -18°c no bacteria can continue to multiply, thus you have a longer storage time. But they will not all be killed by freezing. If your freezer is not cold enough, even though the food is 'frozen', bacteria can still multiply and render the food unsafe to be eaten.

Make sure the freezer or fridge aren't overloaded. There must always be room for free-flow air to circulate to maintain the temperature. Overloading and too much frost will mean the appliance is struggling to do its job and probably costing you lots more in your power bill to do so.

Fridges and freezers should be commercial appliances. A commercial premise puts too much strain on a domestic appliance for it to do its job well.

In between hot and cold

Minimising the time in between hot and cold is essential to avoid bacteria that survived the cook stage by sporulating to begin multiplying again and possibly making toxins in the food.

In transferring heated food to cool storage, once removed from the heat, leave the food (covered lightly to prevent contamination) at room temperature for no longer than ½ to one hour before putting it in the fridge or freezer. If you leave this stage too long, bacteria in the food can begin to multiply and make the food unsafe to eat, either due to bacterial load or toxins produced in the food.

To increase the speed of food cooling down either slice it straight away or divide it into flat trays so that more of it is exposed to room temperature to cool it faster. Slicker pad styled stirrers can also cool food quickly. Trays can also be sat in iced water or on crushed ice to cool the contents quickly. Whatever you do, minimise the time in between hot and cold. Obviously, you also mustn't put hot food into fridges or freezers too soon as then the whole appliance is heated up and all the food is at risk. Once you can no longer see steam rising from the food is the best way to tell it's time.

Temperatures should be recorded to show the ongoing picture of safe food storage (and display -see later). These records should be monitored to ensure appropriate measures are taken immediately if something goes wrong.

For instance, if there has been a power cut and food in freezers has thawed out, must it be thrown out? Can it be sold or used as fresh? Or can it be cooked and made safe that way? The action taken must match the risk.

Viruses

Viruses are also microscopic, but are not actually live cells. Viruses need to combine with a live cell where they act sort of like a parasite, taking over the cell and changing its nature and function to something harmful. They are likely to get into food in similar ways to bacteria and can affect any food type. They don't multiply in food they just use the food as a vehicle to get around.

Some of the viruses common to food borne illness in New Zealand include:

  • Rotavirus These can cause fever, vomiting and watery diarrhoea starting 24 - 72 hours after consumption lasting 4 - 6 days.
  • Norwalk These can cause nausea, vomiting, diarrhoea, abdominal pain, muscle pain and headache, fever and general malaise starting 10 - 50 hours after consumption lasting 24 - 48 hours.
  • Hepatitis A You will note that viral illness tends to show itself faster than many bacteria, much like a toxin, or food poisoning. They also tend to last longer and are more severe. It is believed that many food borne viral illness go unidentified as such and that viral contamination of food is becoming much more prevalent than it used to be. It is therefore even more important for premise cleaning and personal hygiene measures to be used thoroughly, stringently and frequently.

Chemical Contaminants

Metallic compounds are naturally present in many foods in low concentrations which are not harmful. But some excessive amounts get into foods via herbicidal, antifungal and insecticidal sprays of fruit and vegetables, plumbing pipes for drinking water reticulation or from ceramic glazing, tin can coatings or trade waste contaminated waters in which seafood are harvested.

Some metals which can become food contaminants in these ways include:

  • Copper
  • Lead
  • Zinc
  • Antimony and cadmium
  • Aluminium
  • Mercury

Some other food borne chemical contaminations include arsenic, selenium sodium nitrite, from meat pickling, algae toxins and some other pesticides. Your local Health Protection Officers from the Ministry of Health will periodically sample foods at the point of processing, and recreational waters, to test for harmful levels of these contaminants to ensure the Food Regulations (or new ANZFA regulations) are not breached.

To help prevent illness from chemicals and metals you must ensure that:

  • all fruit and vegetables are thoroughly washed prior to use,
  • all metal cook ware and utensils are of high quality and in good condition,
  • you use a council supplied water source (as opposed to a private one) so that the water will be tested for chemical and metals,
  • do not use crockery that has been imported without customs and MAF checking to ensure the glazes are safe to eat from,
  • you must be particularly careful with the storage of acidic foods as these can cause leaching of the metal from the container.
  • you must also be sure that any shellfish have been harvested from proven safe waters
  • and that any pickled meats you purchase have come from licensed butchers to ensure that their pickling solutions are of the correct concentrations.

All the remaining sections of this text combine to show you how to prevent food borne illness. Contamination is an aspect of food safety that there is no excuse for. What is not already there naturally must not be allowed to get there, and what is there naturally must be controlled. Knowledge of the risks associated with different food types will help you decide how to treat each food item you deal with and prevent the three different types of contamination at all times.

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