enumerate Flashcards
classification of food borne illness
lnfection: Ingestion of harmful microorganisms
● lntoxication: Ingestion of toxins produced in food
● Toxin-Mediated Infection: Ingestion of harmful microorganisms that produce toxins in the
body
Types of Microorganisms
1.Beneficial Microorganisms:Used in food production, such as in making bread, beer, yoghurt,
and cheese.
2. Harmful Microorganisms: Spoil food and cause diseases
Bacteria and Their Forms/ state
Bacteria are the most common threat to food safety.
● They can exist in vegetative or spore states.
● Vegetative: Active state where bacteria grow and reproduce.
● Spore: Dormant state that can survive harsh conditions, such as cooking or freezing
Bacteria is classified as:
——Spoilage bacteria
● break down foods making them look, taste, and smell bad.
● They reduce the quality of food to unacceptable levels.
● When this happens, the food will have to be thrown away.
—-Pathogenic bacteria
● can make people ill if they or their toxins are consumed through food.
trivia
Bacterial Growth
● Bacteria reproduce when bacterial cell divides to form two new cells.
● This process is called binary fission.
Generation Time
● or the time for cell numbers to double
● 20-30 mins but can also be quick as 15 mins.
Phases of Bacterial Growth
- Lag phase: no increase in number of living bacterial cells
- Log phase: exponential increase in number of living bacterial cells
- Stationary phase: plateau in number of living bacterial cells; rate of cell division and
death roughly equal - Death or decline phase: exponential decrease in number of living bacterial cells
Bacterial Growth Requirements
Key factors affecting bacterial growth
FATTOM
meaning of fattom
- Food: Nutrients required for growth, especially protein-rich foods.
- Acidity: Optimal pH range is 4. 6 to 7.5 for bacterial growth.
- Temperature: Growth is most rapid between 5 °C to 60°C (Temperature Danger Zone 40°C140 F).
- Time: Bacteria need about 4 hours to multiply to dangerous levels.
- Oxygen: Varies by bacteria; some need oxygen (aerobic), others grow without it (anaerobic).
- Moisture: Water activity (aw) must be above 0.85 for bacteria to grow.
Classification of Microorganisms
according to Temperature Requirements
- Psychrophiles
● cold temperature loving microorganisms
● temperature range of 0°C to 21°C. - Mesophiles
● Theses middle range bacteria
● grow at temperatures between 21°C and 43°C - Thermophiles-● Heat loving microorganisms
● grow best at temperatures above 43°C
● all thermophilic bacteria are spoilage organisms.
Spores are most likely to turn vegetative
when:
● heat-shocked (heating causes spores to change);
● optimum conditions exist for growth (high protein and high moisture);
● temperatures are in the food temperature danger zone or between 5°C to 60°C
● the amount of time the food is in the danger zone is four hours or more.
Foodborne Illnesses Caused by Bacteria
bacillus cereus
clostridium perfringes
clostridium botalinum
bacillus cereus type of illness s and Onset Time
Type of Illness:
● Bacterial intoxication or toxin-mediated infection
Symptoms and Onset Time
● onset time for the vomiting type is 30 minutes to 6 hours, usually lasting for a day or
less.
● onset time for the diarrheal illness is 8 to 16 hours and lasts for 12 to 14 hours.
one of the most commonly reported causes of foodborne illnesses, especially for food
that have been temperature abused.
Clostridium perfringens
Clostridium perfringens:
Type of Illness:
Symptoms and Onset Time:
Type of Illness:
● Bacterial toxin-mediated infection
Symptoms and Onset Time:
● It causes intense abdominal pains and severe diarrhea.
● 8 to 22 hours and the illness usually lasts for a day or less
an anaerobic,causes foodborne intoxication due to improperly heat processed foods,
especially home canning ones.
. Clostridium botulinum
