3.4.1.3 Microbial Contamination

• Microbial contamination occurs when food is contaminated with harmful microorganisms such as bacteria, viruses, or moulds
• Food can become contaminated with Salmonella bacteria if it comes into contact with contaminated surfaces or is not stored properly.
• What is the most common type of microorganism causing food contamination?

  Bacteria
• Moulds are fungi that can grow on food and produce toxins
• Which type of bacteria is commonly found in raw meat, poultry, and eggs?

  Salmonella
• High-moisture foods like bread and fruits are more susceptible to mould growth.
• Pickling vegetables increases acidity, which prevents bacterial growth
• What type of packaging reduces oxygen levels to slow down aerobic bacteria?

  Vacuum-packing
• Microorganisms thrive in a specific temperature range, most commonly between 5°C and 63°C.
• Arrange the key conditions influencing microbial growth in food in order of importance

  1️⃣ Temperature

  2️⃣ Humidity

  3️⃣ pH

  4️⃣ Nutrients

  5️⃣ Time

  6️⃣ Oxygen Levels
• What temperature range is ideal for most microorganisms to thrive in food?

  $5^{\circ}C - 63^{\circ}C$
• Microorganisms need moisture to grow, which is measured by water activity
• Bacteria often thrive in neutral to slightly acidic conditions.
• What type of pH conditions do bacteria prefer?

  Neutral to slightly acidic
• Pickling vegetables increases acidity to prevent bacterial growth.
• Microbial growth in food is influenced by several key conditions
• Match the microbial growth condition with its description:

  Temperature ↔️ Microorganisms thrive between $5^{\circ}C$ and $63^{\circ}C$

  Humidity ↔️ Measured by water activity ($a_{w}$)

  pH ↔️ Bacteria prefer neutral to slightly acidic conditions
• Order the factors that influence microbial growth in food based on their relevance.

  1️⃣ Temperature

  2️⃣ Humidity

  3️⃣ pH

  4️⃣ Nutrients

  5️⃣ Time

  6️⃣ Oxygen Levels
• Some microorganisms require oxygen (aerobic), while others thrive without it (anaerobic). Vacuum-packing foods limits oxygen, slowing down aerobic bacteria
• What are the primary sources of microbial contamination in food?

  Raw materials, handling, environment, equipment, cross-contamination
• Cross-contamination occurs when microorganisms transfer from raw to cooked food.
• Match the illness with its causative microorganism and potential long-term effects:

  Salmonellosis ↔️ Salmonella bacteria, reactive arthritis

  Norovirus Infection ↔️ Norovirus, dehydration

  Hepatitis A ↔️ Hepatitis A virus, liver damage

  coli Infection ↔️ E. coli bacteria, kidney failure

  Giardiasis ↔️ Giardia parasite, malabsorption
• Microbial contamination occurs when food is contaminated with harmful microorganisms
• What are the two primary health risks associated with consuming contaminated food?

  Food poisoning, foodborne illnesses
• Microbial contamination occurs when food is contaminated with harmful microorganisms such as bacteria, viruses, or moulds
• Salmonella bacteria can contaminate food if it comes into contact with contaminated surfaces.
• What is the causative microorganism for Salmonellosis?

  Salmonella bacteria
• Match the microorganism with its associated foodborne illness:

  Salmonella bacteria ↔️ Salmonellosis

  Norovirus ↔️ Norovirus Infection

  Giardia parasite ↔️ Giardiasis

  coli bacteria ↔️ E. coli Infection
• What temperature range do microorganisms thrive in?

  5^{\circ}C</latex> to $63^{\circ}C$
• Bacteria prefer neutral to slightly acidic pH conditions.
• What is the measure of moisture in food called?

  Water activity
• Vacuum-packing foods limits oxygen, which slows down aerobic bacteria.
• Where can Salmonella be found in raw materials?

  Raw chicken
• Order the steps that can lead to microbial contamination in food.

  1️⃣ Microorganisms present in raw materials

  2️⃣ Improper handling during preparation

  3️⃣ Cross-contamination from raw to cooked items

  4️⃣ Microbial growth due to poor hygiene
• Cross-contamination is a common issue during food preparation.
• What are the potential long-term effects of consuming microbially contaminated food?

  Reactive arthritis, liver damage
• Washing hands thoroughly with soap and water for at least 20 seconds is crucial to prevent contamination.
• Reheating leftover soup to $74^{\circ}C$ kills bacteria.
• What is the purpose of using separate cutting boards for raw meat and vegetables?

  Prevent cross-contamination