info - food safety

food hygiene FAQ

• what is food spoilage, food contamination and food poisoning?

  Food spoilage is defined as:

  "foods that are physically ruined, and are therefore normally easily recognisable and generally unsuitable for consumption. If digested these foods may or may not cause food poisoning depending on the food and its level and type of spoilage"

  Examples of food spoilage would be:

  • mouldy bread
  • mouldy or bruised fruit
  • mouldy cheese
  • fermented fruit juices

Food contamination is defined as:

when foods have harmful, unwanted substances or micro-organisms present. foods can be contaminated in one of three ways, physically, chemically and microbiologically. These foods if digested may or may not cause physical damage or food poisoning depending on the type and level of contamination. In most cases contaminated foods will probably look quite normal, healthy and edible, unless closely inspected."

Examples of food contamination would be finding the likes of the following in your food:

• an insect
• strand of hair
• band aid
• finger nail
• shard of glass or metal
• food tasting soapy (from unrinsed equipment, cutlery, etc)

Food poisoning is defined as:

the result of ingesting something: foods, drinks etc that have been contaminated with an agent causing sickness. symptoms can be mild to severe to fatalities

• what are the symptoms of food poisoning, is it only vomiting & diarrhoea?

  The symptoms depend mainly on the type of pathogen (food poisoning bacteria) that has been consumed. Symptoms of food poisoning includes, but not limited to:

  • nausea
  • stomach cramps
  • vomiting
  • dysentery / diarrhoea
  • fever
  • headache
  • muscular pain

• what is a high risk food?

  A high risk food is defined as any food high in fat or animal protein as they spoil easily without refrigeration and foods that because of their natural state may contain a high amount of bacteria/pathogens

• so bacteria only live on high risk foods?

  NO. Bacteria are found everywhere, for example:

  • in the air on dust
  • in the soil
  • in water
  • in and on people
  • in and on animals and insects
  • on plants
  • on kitchen work surfaces
  • on kitchen equipment

• what do bacteria need to survive or multiply?

  bacteria are 'asexual' and multiply by a process called 'binary division'. This means that they do not require a male and female to reproduce, under the right conditions they merely split into two. For this process to take place ALL bacteria require the following:

  		warmth	:	between 5°C and 65°C (body temperature is best - 37°C)
  		moisture	:	so dehydrated foods are safe until water is added back
  		food	:	meaning a food source, like our skin
  		ph	:	a neutral ph level
  		time	:	given the above bacteria will multiply every 20 minutes

  It is for the above reasons, that most food preserving methods, eliminate one or more of these conditions.

  If a single bacterium was allowed to reproduce every 20 minutes, after 24 hours there would be 5 billion, billion of them!!

• what about oxygen?

  Some bacteria require oxygen (known as aerobic bacteria) but some will survive in airless conditions like vacuum seals, these are known as anaerobic bacteria.

• does chilling foods kill bacteria?

  NO. Bacteria will simply lay dormant or reproduce very, very slowly.

• does freezing foods kill bacteria?

  NO. Bacteria will simply lay dormant and then commence to multiply when the food is defrosting. Therefore foods must be defrosted in the fridge, or left no longer than two hours at room temperature to defrost.

• how do bacteria travel?

  Essentially they cannot move by themselves, they require something or someone to transfer them from A to B. These are known as bacterial vehicles, such as human hands, knives and any other item, thing or animal that may be in the kitchen, also dust will carry bacteria.

  It is these bacterial vehicles and the transferring of bacteria from one food to another that we call cross contamination.

• is it only bacteria that can cause food poisoning?

NO. Besides chemicals that can get into our foods, other organisms like moulds, yeasts and viruses can also be a problem.

Also some bacteria produce a toxin (a poison) that is harmful.

• so cleaniness really is next to godliness?

  In any kitchen whether it is at home or a commercial entity, cleanliness and good hygiene is essential.

• is applying chemicals the best way to destroy or control bacterial growth?

  NO. They will, but are not recommended for prolonged use.

  Just like humans and anti-biotics, bacteria will build up an immunity to the chemical. If you apply a chemical to 1,000 bacteria and only 1 of them is immune, that means that when it reproduces there will be 2 immune bacteria, in another 20 minutes, 4 immune bacteria and in 24 hours that one immune bacteria has multiplies to 5 billion, billion that are all now immune.

• how are bacteria best destroyed?

  Temperature is by far the best. Either the application or removal thereof.

  		keep frozen food frozen	:	-18°C
  		keep chilled foods chilled	:	2°C to 4°C
  		cook foods thoroughly	:	70°C and above

• how else can I control bacteria and keep food safe?

• remember the four C's <click here>
• remember to keep hands ultra clean, especially after handling foods, touching body parts such as scratching or touching your hair
• sneeze and cough away from foods and wash hands afterwards
• dry with paper towels and not cloth towels
• don't lick your fingers, taste foods with a spoon or fork
• never 'double dip
• use tea towels for polishing only and not drying
• allow dishes to drip or air dry

• can I safely use the microwave to defrost foods?

  YES. but only within certain limits. Only use it to defrost small items that will then be cooked straight away. Larger items will tend to partially cook in the microwave and dry out.

• does the 4 second rule really apply if I drop foods on the floor?

  NO, definitely not.

  As soon as food comes into contact with an unhygienic surface bacteria are transferred.

  Besides bacteria of course, cockroach eggs, fly eggs and all manner of microscopic items can be transferred.

  Wash it and cook it!

• hot foods in cold fridge?

  In a large walk in commercial fridge this is not too much of a problem, in a domestic fridge it can cause all manner of problems.

  Understanding the principle here is a must. The reason for not doing it is to prevent the air inside heating up, and warming foods above 4C.

  • large amounts of hot food in a small fridge NO
  • small amounts of food in a large fridge OK

So its all about volume.

• how are foods best cooled before going into the fridge?

  Break foods down into the smallest amounts as possible

  • place into containers that are wide and open to allow heat to disperse
  • place into containers like metal or glass to allow heat to disperse, not plastic which retains the heat
  • keep foods covered with netting or similar
  • put a fan near the foods
  • cool at room temperature for no more than 2 hours

• what are the top tips for purchasing and transporting foods after shopping?

• first and foremost organisation
• look for the use by dates, etc
• conduct food shopping last, and only AFTER you have completed all your other chores; going to the bank, post office, etc
• take a chiily bin or similar for your frozen goods
• do not leave chilled and frozen foods sitting in the back of your car, especially on a hot day
• do not take the family dog etc with you

• is there any special way of setting up a fridge shelving?

  Most modern fridges have special compartments these days, especially in the door for dairy products, etc but the following tips will be useful:

  • salad vegetables are best stored in sealed containers above raw meats and shellfish, despite the compartment often being on the bottom shelf. he two main reasons for this is to prevent blood etc dripping on them and also prevents delicate items freezing
  • the coldest part of a fridge is usually the bottom, this is where meats and seafood are best stored. if the vegetable compartments are at the bottom use them for storing meats and shellfish instead
  • always place cooked foods (meat and seafood) above raw
  • dairy products on top shelf

and keep all foods in sealed plastic containers

• what is the safest way to re-heat foods?

• first and foremost only re-heat foods ONCE. so only re-heat as much as you need
• constant re-heating of foods can cause bacteria to form spores, which are heat resistant and will not be destroyed by cooking, these spores can cause very severe food poisoning
• heat solid foods until HOT, HOT, HOT all the way through (above 70°C)
• slowly heat liquid foods, soups and stews etc to boiling point, simmering for a minimum of three minutes and ensuring the food is stirred to distribute the heat evenly

• what is the best way to wash my hands?

• use running water (cold is just as effective as hot)
• wet hands and apply soap
• lather up and scrub for 20 seconds (two rounds of the happy birthday song)
• rinse thoroughly
• dry thoroughly using paper towels

• why is cold water just as good as hot for hand washing?

  The main thing when hand washing, when the aim is to reduce bacterial contamination is friction, physically removing and rinsing.

  Bacteria do not die until heat of approximately 65°C is applied for approximately 3 minutes, at this temperature and time a person would receive severe burns.

  So apart from the soap may work better in warmer water, bacteria is removed or controlled when hand washing by scrubbing them off and rinsing them away, just like surgeons do prior to operating.

• what do all those dates mean on my processed food packaging?

  Normally foods will be labelled with one of four dates, the exact requirement for each date will differ from country to country. But a good general guideline would be:

  'use by'
  relates to food safety and Indicates when for health reasons the food should be consumed by. Providing the intact package is stored in accordance with any stated storage conditions the product should remain safe to eat until the 'Use By' date.

  • foods should not be consumed once the 'Use By' date has past
  • foods cannot be sold beyond their 'Use By' date

'best before'
relates to quality and Indicates when the food should be consumed by to ensure it remains at premium quality.

• foods can be sold beyond their 'Best Before' date provided it is still fit for consumption

'baked on'
relates to bread with a shelf life of less than 7 days and relates to the date on which the bread was baked.

'packed on'
and relates to the date of production or n the case of a larger amount of fresh produce being broken into smaller portions, when it was re-wrapped. Goods may also have other manufacturer's or packer's codes. This date may only be used in addition to a date mark outlined above. May also be referred to as produced on, etc.

email chef@tallyrand.info