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2. (a) List the conditions that are necessary for the growth of micro-organisms - Junior Cycle Home Economics - Question 2 - 2014
Question 2
2. (a) List the conditions that are necessary for the growth of micro-organisms. (b) (i) Name two food poisoning bacteria. (ii) Give a different possible source o... show full transcript
Worked Solution & Example Answer:2. (a) List the conditions that are necessary for the growth of micro-organisms - Junior Cycle Home Economics - Question 2 - 2014
Step 1
List the conditions that are necessary for the growth of micro-organisms.
Answer
The growth of micro-organisms requires several essential conditions:
- Food: Micro-organisms need nutrients to thrive. This may include carbohydrates, proteins, and lipids available in various food sources.
- Warmth: Most micro-organisms grow best at warm temperatures, typically between 20°C to 37°C.
- Moisture: Water is crucial for micro-organism growth, as it aids in biochemical reactions.
- Oxygen: Some micro-organisms require oxygen (aerobic), while others can grow without it (anaerobic).
- pH Level: The acidity or alkalinity of the environment affects micro-organism activity; most prefer a neutral pH.
Step 3
Give a different possible source of each bacteria you have named.
Answer
- Salmonella: A common source of salmonella is undercooked poultry, which can be attributed to poor standard of hygiene in food handling.
- Staphylococcus aureus: This bacteria can be found in improperly stored cooked foods, particularly those that are left out at room temperature for extended periods.
Step 4
List the reasons why food is processed.
Answer
Food processing serves several important purposes:
- Food Safety: Processing helps eradicate micro-organisms, preventing foodborne illnesses.
- Preservation: It extends the shelf-life of food, making it more durable for storage and transport.
- Variety: Processed foods provide a variety of options, catering to different tastes and preferences.
- Convenience: Processed foods are designed for easy use, saving time in preparation.
Step 5
State the guidelines to follow when freezing vegetables.
Answer
- Choose good quality vegetables: Start with fresh, ripe vegetables that are free from blemishes or decay.
- Prepare as for cooking: Clean the vegetables thoroughly and cut them into appropriate sizes.
- Blanch: Briefly boil the vegetables, then chill in ice water to preserve color, flavor, and texture before freezing.
Step 6
Explain the terms: blast freezing and quick freezing.
Answer
Blast Freezing: This is a method where food is rapidly frozen at very low temperatures, typically around -30°C, using high-velocity cold air. This helps to preserve the quality and nutritional value of food by minimizing ice crystal formation.
Quick Freezing: This refers to freezing techniques that take place at temperatures of -25°C or lower, ensuring that ice crystals form quickly and remain small, which helps preserve the texture and flavor of the food.