Cross- contamination - Preparing food

food safety and food poisoning

What is cross contamination?

- When microorganisms are transferred from raw to cooked foods, causing infection.

What are some rules for food hygiene?

- Wash hands thoroughly before handling food and between handling different food types.
- Keep raw and cooked foods separate and use different equipment to prepare them.
- Have good personal hygiene- wear clean protective clothing, cover cuts and never sneeze or cough on food.
- Keep all working surfaces and utensils clean. Use antibacterial spray.

What are some (more) rules for food hygiene?

- Cover and cool all cooked foods rapidly and refrigerate as quickly as possible. Store below 5°C.
- Do not put hot foods in the refrigerator as it will raise the temperature of other foods in the refrigerator
- Keep pets away from food preparation areas.
- Take care of waste disposal. Keep bins covered and emptied and wash them regularly.

How to prevent cross-contamination?

- Avoid allowing raw and cooked foods to touch each other, for example, raw chicken and boiled ham.
- Avoid direct- contamination
- Avoid indirect- contamination

What is direct contamination?

- Allowing the blood and juices from raw food to drip onto cooked foods, for example putting raw meat above cooked foods in the refrigerator

What is indirect contamination?

- allowing bacteria to be transferred during handling or preparation, eg. hands, work surfaces, equipment or clothing.

What do the chopping board colours mean?

- Red - raw meat
- Yellow - cooked meat
- Brown - cooked fruit and veg
- Green - raw fruit and veg
- Blue - fish
- White - dairy and bakery

What causes most food poisoning?

- Bacterial contamination

What type of bacteria causes food poisoning?

- Pathogenic bacteria example salmonella

Why has there been an increase in cases of food poisoning?

- More people are using microwaves often meaning food is not defrosted or cooked to the correct temperature
- Increased use of chill-cooked foods which are high-risk foods
- Foods not stored at the right temperature
- Food not prepared correctly
- Poor personal hygiene practices.
- Hot foods not kept at the right temperatures, above 63°C
- Not reheating foods to the correct temperature for the correct amount of time

What are some causes of food poisoning?

- not thawing foods correctly
- preparing foods too far in advance
- undercooking high-risk foods like chicken
- not allowing foods to cool before putting them in chill cabinet freezers - 90 minutes to chill below 8°C

What are some causes of food poisoning?

- not reheating foods to the correct temperature - over 7°C- for a long enough time.
- keeping hot foods under 63°c
- leaving food on display at room temperature for longer than the maximum safe period of 4 hours
- not checking temperatures accurately

What are some bacteria leading to food poisoning?

- Salmonella
- Staphylococcus aureus
- Clostridium perfringens
- Bacillus cereus
- Campylobacter
- Listeria
-E. coli

What are possible sources of Salmonella?

Poultry, eggs, meat

What are possible sources of Staphylococcus aureus?

Food handlers

What are possible sources of Clostridium perfringens?

Raw foods, such as vegetables and meat

What are possible sources of Bacillus cereus?

Cereals, especially rice

What are possible sources of Campylobacter?

Infected animals, birds and unpasteurised milk

What are possible sources of Listeria?

Raw, processed and cooked foods (e.g. soft cheese)

What are possible sources of E. coli?

Cattle, raw meat and raw milk.