Food Safety - Standard 7 - General Science - Balbharati
Food Safety
Exercise
Q. 1 Complete the following statements by using the correct option from those given below.
(Irradiation, dehydration, pasteurization, natural, chemical)
(a) Drying the food grains from farms under the hot sun is called dehydration.
(b) Materials like milk are instantly cooled after heating up to a certain high temperature. This method of food preservation is called pasteurization.
(c) Salt is a natural type of food preservative.
(d) Vinegar is a chemical type of food preservative.
Q. 2 Answer the following questions in your own words.
(a) How is milk pasteurized?
Ans. The pasteurization method involves heating the milk at 80° C for 15 minutes and cooling it quickly. This destroys the microbes present in the milk and it keeps for a longer duration.
(b) Why should we not consume adulterated food materials?
Ans. Consuming adulterated food is not safe because it can harm our health. Adulteration means adding harmful or low-quality substances to food to make more money or preserve it for longer. When we eat adulterated food, it can make us sick or cause long-term health problems. So, it's important to avoid it and choose food that is pure and safe to eat to stay healthy.
(c) What precautions do your parents take to keep foodstuffs safe?
Ans. [Note : Sample of answer is given below but students should write their own answer.]
1. Before using fruits and vegetables, they are often washed thoroughly to remove dirt, chemicals, and bacteria.
2. Cooking food at high temperatures helps kill harmful bacteria and parasites. This is especially important for meat, poultry, and seafood.
3. Boiling tap water to make it safe for drinking and cooking, as it can be contaminated with harmful microorganisms.
4. Leftovers and perishable foods are stored in the refrigerator to prevent spoilage.
5. They use spices like turmeric, cumin, and coriander, which not only add flavor but also have antimicrobial properties that can help preserve food.
6. Using natural preservatives like vinegar, lemon juice, or oil to extend the shelf life of homemade pickles and chutneys.
8. Keeping the kitchen and utensils clean is essential to prevent cross-contamination and the growth of harmful bacteria.
9. To prevent contamination from dust and insects, many households store grains and spices in closed containers.
(d) How does food spoilage occur? Which are the various factors spoiling the food?
Ans. Food spoilage occurs when food becomes unsafe or unpleasant to eat due to the growth of microorganisms, chemical changes, or physical damage.
Several factors can contribute to food spoilage:
1. Microorganisms can spoil food. They multiply rapidly in favorable conditions, breaking down food components and producing harmful substances or off-flavors.
2. Enzymes naturally present in food can lead to spoilage by causing chemical reactions that change the taste, texture, and color of the food. For example, enzymes can cause fruits to ripen and become overripe.
3. Excess moisture in food can create an environment where microorganisms grow well.
4. Temperature plays a crucial role in food spoilage. Higher temperatures can speed up the growth of microorganisms, while lower temperatures can slow or halt their growth. Keeping food at the right temperature is essential to prevent spoilage.
5. Oxygen can cause oxidative spoilage in certain foods, such as fats and oils. It can lead to rancidity, a process where fats become unpleasantly smelling and tasting.
6. Food can become contaminated with harmful microorganisms through contact with dirty hands, utensils, or surfaces.
7. Inadequate packaging can allow air, moisture, or light to enter, leading to spoilage. Proper packaging, such as vacuum sealing or airtight containers, helps preserve food.
8. Food naturally deteriorates over time due to various factors. Even with proper storage, most foods have a limited shelf life before they start to spoil.
12. Physical damage, such as hurting or crushing, can speed up spoilage in fruits and vegetables by providing entry points for microorganisms.
(e) Which methods of food preservation would you use?
Ans. [Note : Students should write their own answer]
Q. 3 What shall we do?
(a) There are vendors selling uncovered sweetmeats in open places in the market.
Ans. If vendors are selling sweetmeats without any covering in open places in the market, you should avoid buying them because they can get dirty and contaminated.
(b) A pani-puriwalla is serving the pani puri with dirty hands.
Ans. If a pani-puri vendor is serving pani puri with dirty hands, it's best to skip buying from that vendor to prevent the risk of getting sick.
(c) We have purchased a large quantity of fruits and vegetables.
Ans. If you've purchased a large quantity of fruits and vegetables, make sure to store them properly in clean and dry places to keep them fresh for a longer time.
(d) We need to protect foodstuffs from pests like rats, cockroaches, wall- -lizards, etc.
Ans. To protect your food from pests like rats, cockroaches, and wall-lizards, store it in sealed containers or cabinets to keep these creatures away and maintain food hygiene.
Q. 4 Find the odd-man-out.
(a) salt, vinegar, citric acid, sodium benzoate
(b) lakhi dal, brick dust, metanyl yellow, turmeric powder
(c) banana, apple, guava, almond
(d) storing, freezing, settling, drying
Q. 5 Complete the chart below.
| S. No. | Foodstuff | Adulterant |
|---|---|---|
| 1. | Turmeric powder | Metanyl yellow |
| 2. | Black pepper | Dried papaya seeds |
| 3. | Rava | Iron filings |
| 4. | Honey | Jaggery, Water, Sugar |
Q. 6 Explain why this happens and suggest possible remedies.
(a) Qualitative wastage of food.
Ans. Qualitative wastage of food happens when we buy too much or don't store food properly. To reduce it, plan meals, buy what's needed, store correctly, and use leftovers creatively.
(b) The cooked rice is underdone.
Ans. Undercooked rice occurs due to not enough cooking time or water. Follow cooking instructions and adjust time and water accordingly.
(c) The wheat that was bought is a bit moist.
Ans. Moist wheat comes from humidity. Dry it in the sun and store in a dry, airtight container.
(d) The taste of yoghurt is too sour/slightly bitter.
Ans. Sour yogurt results from leaving it out too long or using old milk. Store in the fridge and use fresh milk.
(e) Cut fruits have turned black.
Ans. Cut fruits turn black due to oxygen exposure. Sprinkle lemon juice, store in the fridge in an airtight container.
Q. 7 Give reasons.
1. Food remains safe at 5° Celsius.
Ans. Food stays safe at 5°C because this temperature slows down the growth of harmful bacteria. Thus, food remains fresh and safe at 5° Celsius.
2. Nowadays, food is served buffet style during large gatherings.
Ans. Buffet-style food service is favored at large gatherings because it offers various dishes to suit different preferences. It also allows people to serve themselves, reducing the need for servers.
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