Home Economics - Junior Secondary 3 - Food contamination and poisoning

TERM: 2^ND TERM

WEEK: 3

CLASS: Junior Secondary School 3

AGE: 14 years

DURATION: 40 minutes each for 2 periods

DATE:

SUBJECT: Home economics

TOPIC: Food contamination and poisoning

SPECIFIC OBJECTIVES: At the end of the lesson, the learners should be able to

1. ) Define food contamination
2. ) State the causes of food contamination and poisoning
3. ) List the sources of food contamination and poisoning
4. ) Mention the symptoms of food poisoning

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, story-telling, videos from source

INSTRUCTIONAL MATERIALS: Recommended Home economics textbooks for Junior Secondary School 3

INSTRUCTIONAL PROCEDURES: PERIOD 1-2:

NOTE

FOOD CONTAMINATION AND POISONING

Food contamination occurs when harmful substances such as bacteria, viruses, parasites, chemicals, or physical objects get into food, making it unsafe for consumption. Contaminated food can lead to foodborne illnesses or poisoning if consumed.

Causes of Food Contamination and Poisoning

The main causes of food contamination and poisoning include:

• Microbial Contamination: The presence of harmful bacteria (e.g., Salmonella, E. coli), viruses (e.g., norovirus), or parasites (e.g., Giardia) that can cause illness when ingested.
• Chemical Contamination: The presence of harmful chemicals, such as pesticides, heavy metals, food additives, or toxins, that can contaminate food.
• Physical Contamination: The presence of foreign objects such as glass, plastic, metal, or hair in food, which can cause injury or illness.
• Cross-contamination: When harmful microorganisms from raw foods, such as meat, come into contact with ready-to-eat foods like vegetables or cooked foods.
• Improper Storage: Storing food at unsafe temperatures can cause the growth of bacteria and mold, leading to food spoilage and contamination.
• Improper Handling: Handling food with dirty hands, unclean utensils, or surfaces can introduce harmful pathogens.

Sources of Food Contamination and Poisoning

Common sources of food contamination and poisoning include:

• Raw meats, poultry, and seafood: These can harbor harmful bacteria and parasites if not properly handled or cooked.
• Fruits and vegetables: Can be contaminated by bacteria or chemicals during growth, harvesting, or handling.
• Dairy products: Milk, cheese, and other dairy items can be contaminated with bacteria like Salmonella or Listeria if not pasteurized or properly stored.
• Water: Contaminated water used for washing, cooking, or drinking can introduce harmful microorganisms.
• Food handlers: People who prepare or handle food can transfer germs through improper handwashing or handling practices.
• Improperly canned or preserved foods: Bacteria such as Clostridium botulinum can grow in improperly canned foods, leading to botulism.
• Contaminated equipment or utensils: Knives, cutting boards, or kitchen tools that are not properly cleaned can transfer harmful microorganisms onto food.

Symptoms of Food Poisoning

The symptoms of food poisoning can vary depending on the cause of contamination but commonly include:

• Nausea and vomiting
• Diarrhea (sometimes with blood or mucus)
• Abdominal pain or cramps
• Fever (in some cases)
• Headaches
• Weakness or fatigue
• Dehydration, which can lead to dry mouth, dizziness, and dark urine
• Muscle aches and joint pain

EVALUATION:

1. What are the main differences between bacterial, viral, and parasitic food contamination, and how do they affect the body differently?
2. How can cross-contamination occur in the kitchen, and what steps can be taken to prevent it during food preparation?
3. Explain the role of temperature in food safety. What are the potential consequences of storing food at improper temperatures?
4. What are some common symptoms of food poisoning, and how can they help determine the cause of the contamination?
5. Identify at least three sources of food contamination and explain how each can be prevented during food handling and preparation.

CLASSWORK: As in evaluation

CONCLUSION: The teacher marks their books and commends them positively