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Micro-organisms and enzymes have a role to play in food spoilage and food production - Leaving Cert Home Economics - Question 3 - 2022
Question 3
Micro-organisms and enzymes have a role to play in food spoilage and food production. (a) Discuss the role of enzymes in relation to food spoilage. (b) Name and gi... show full transcript
Worked Solution & Example Answer:Micro-organisms and enzymes have a role to play in food spoilage and food production - Leaving Cert Home Economics - Question 3 - 2022
Step 1
Discuss the role of enzymes in relation to food spoilage.
Answer
Enzymes play a crucial role in food spoilage by facilitating various chemical reactions that lead to the deterioration of food quality.
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Over-ripening: Enzymes in ripe fruits continue to act after harvesting, which can lead to over-ripening and subsequent decay. For example, enzymes such as those involved in softening may cause fruits to become mushy.
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Enzymatic Browning: This process occurs when fruits and vegetables are cut or peeled, exposing them to oxygen. The enzyme polyphenol oxidase (PPO) reacts with phenolic compounds, resulting in browning, which is commonly seen in apples and bananas. This not only affects visual appeal but may also alter taste.
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Enzyme Deactivation: To prevent spoilage, food may be treated through methods like heating or freezing to deactivate enzymes that can cause a decline in quality. For instance, blanching vegetables before freezing helps to minimize spoilage by inactivating enzymes that may otherwise lead to flavor and color loss.
Step 2
Name and give details of one type of mould.
Answer
Mucor
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Characteristics/Description: Mucor is a type of saprophytic mould that has white hyphae and produces sporangia. Mucor reproduces both sexually and asexually. The optimum growth temperature for Mucor ranges from 30°C to 40°C.
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Conditions Necessary for Growth:
- Food Source: Saprophytic moulds thrive on decaying organic matter, often found on bread, jam, cheese, and fruit.
- Oxygen: Mucor requires oxygen to grow, as it develops on the surface of food.
- Temperature: Optimal growth occurs at temperatures between 30°C and 40°C, while lower temperatures (below 15°C) can lead to slow growth.
- Moisture: Moisture levels must be adequate; Mucor prefers slightly acidic conditions to thrive.
Step 3
Assess the uses of micro-organisms in food production.
Answer
Micro-organisms play a vital role in various aspects of food production.
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Fermentation: Yeasts, such as Saccharomyces cerevisiae, are crucial for converting sugars into alcohol and carbon dioxide. This process is essential for products like bread and alcoholic beverages.
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Preservation: Lactic acid bacteria are employed in the production of fermented foods, such as yogurt and sauerkraut. They produce lactic acid, which lowers pH and inhibits the growth of spoilage-causing bacteria.
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Flavor Development: Different bacteria, yeasts, and moulds contribute unique flavors to a variety of foods. For example, Penicillium species are used in cheese production to develop distinct flavors in varieties like blue cheese.
In summary, the strategic use of micro-organisms not only enhances the safety of food by inhibiting spoilage but also enriches the sensory properties of many food products.