Food Safety
Based on Maharashtra Board General Science Chapter 5-Food Safety-Audio Notes, Solution, Video, PDF, Test
Notes
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All constituents of food-carbohydrates, fats, proteins, vitamins, minerals, fibre and water are necessary for the proper growth of the body
(1) Food / Source - Jowar, wheat, millet (bajra), rice
Nutrients obtained - Carbohydrates
Function in body -Providing of energy
(2) Food / Source -Beans and pulses
Nutrients obtained - Proteins
Function in body -Growth and development of body, repairing wear and tear of the body.
(3) Food / Source- Oil, ghee, etc
Nutrients obtained - Fats
Function in body -Provides energy.
(4) Food / Source -Fruits and vegetables.
Nutrients obtained – Vitamins and Minerals
Function in body -Gives immunity and resistance. Helps in all life processes.
If these food materials are infested by insects or spoiled in any way then such food is not safe for eating.
World Food Day :
(1) On every 16th October, World Food Day is observed.
(2) This day is observed to create awareness among the people for working towards food security and to avoid food wastage.
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Food spoilage : Food is said to be spoiled if there is a change in its colour, odour, texture, quality, taste and there is a loss of its nutrient content, which makes it unsuitable for human and animal consumption.
Factors responsible for food spoilage :
(1) Natural causes : The food stuff may spoil due to natural causes. All food stuffs have their own shelf life. Fruits or their skins turn black and may give out a foul or bad odour.
(2) Internal factors : Factors which are present within the food itself are termed as intrinsic or internal factors. The two main internal factors are moisture content and enzymes.
(3) Man made causes : When there is wrong handling, overcooking, or improper storage, like storing in damp place or problems during transportation results into food spoilage.
(4) Properties of food stuffs : There are some intrinsic factors within the food materials which result into food spoilage. Milk, meat etc. may be acidic or alkaline and they get spoilt early.
(5) Chemical reactions : Some food stuffs undergo chemical reactions on contact with metals and are spoilt. Food must not be stored in metallic and lead containers as lead is poisonous and can cause certain chemical reactions within the food.
(6) Micro-organisms and insects : Food is also spoiled because of the growth of micro-organisms like bacteria, fungi and yeast present in water, soil and air.
Importance of saving the food from spoilage :
(1) With the help of science and technology, India is producing ample foodstuffs such as cereals, fruits, vegetables, fish as well as milk and milk-products.
(2) However, many people in our country and all over the world there is a problems of starvation and hunger. Many do not get enough food and hence we should not waste the food.
Quantitative wastage of food:
(1) Using wrong methods of farming e.g. hand sowing of seeds, inadequate threshing, improper storage, wrong methods of distribution of food, etc.
(2) Feasts and banquets resulting into lots of quantitative loss.
(3) Improper traditions like offering the excessive food.
Qualitative wastage of food :
(1) Using wrong methods of food preservation. Excessive use of food preservatives.
(2) Washing the vegetables after cutting them. Over-cooking the food.
(3) Mis-calculation of the time required to transport food from producers to consumers. Mis-handling of perishable fruits like grapes and mangoes.
Ways to prevent food spoilage and food wastage :
(1) Serve only that you can finish eating.
(2) Eat all the food that has been taken in the plate. Do not throw away left-over food but re-use it instead.
(3) Do not over-cook.
(4) Buy foodstuffs that are needed. Do not over-stuff by excessive purchases.
(5) Store grains and other perishable foodstuffs by using proper methods.
(6) Confirm the expiry date of processed food before it use. [/responsivevoice]
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Food storage and preservation: There are many methods of food storage and preservation. e.g., freezing, drying, boiling, air-tight packing, etc. These different methods help in preventing the growth of micro-organisms in food. Thus the food spoilage is avoided.
Food protection and food preservation :
(1) Food protection : Food protection means preventing the food spoilage by microbia growth and infestation by pests.
(2) Food preservation : Food preservation is use of various preservatives to prevent food spoilage due to internal factors. These methods aim at storing the food for a long time.
Methods of food preservation :
(1) Freezing : Refrigerators are used for freezing the food Due to low temperature of freezers, the biological and chemical reactions in food materials are slow down
Thus food remains unspoiled for a longer period.
(2) Smoking : When the food is preserved with the help of a smoke it is called smoking.
Smoking is used to lengthen the shelf life of perishable food items. This effect is achieved by exposing the food to smoke from burning plant materials such as wood. Most commonly subjected to this method of food preservation are meats and fish that have undergone curing.
(3) Use of insecticides : There are many chemical insecticides which are sprayed on the containers of grains. e.g., Malathion. Insecticides protect the grains by killing infesting insects.
(4) Irradiation : Food js exposed to ionizing radiations. Such as (1) High energy electrons emitted by accelerators (2) X-rays (3) Gamma-rays emitted by radioactive isotopes. Irradiation destroys the microbes, insects, etc.
(5) Use of insert gas : Nitrogen gas is filled in air-tight packets of potato wafers and other food products. This is for prevention of the growth of fungus and insects in them.
(6) Pickling: Pickling is a method of preserving food in an edible anti-microbial liquid. Pickling can be broadly categorized into two categories: chemical pickling and fermentation pickling.
(7) Canning : In this method, air is removed from food and put in airtight cans so that germs do not grow on them. Food items like vegetables, seafood, dairy products etc. Are preserved through this method.
Use of preservatives :
(a) Natural preservatives : Natural preservatives are naturally available materials like salt, sugar and oil.
(b) Chemical preservatives : Chemical preservatives are synthetic preservatives. e.g. Acetic acid (vinegar), citric acid, sodium benzoate and some nitrate and nitrite salts.
Pasteurization : In this method milk or other similar foodstuffs are heated up toa certain temperature, e.g., milk at 80 °C for 15 minutes and then quickly cooled.
Pasteurization destroys the microbes present in the milk and thus milk remains safe.
This process was developed by Louis Pasteur.
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Food adulteration :
The ways of food adulteration :
(1) Removing the important components of food; e.g., Removal of fat content of milk, essence of cloves, cardamoms, etc.
(2) Adding harmful colour to food.
(3) Mixing of a low quality inedible or cheaper material to food.
(4) Mixing of materials like small stones, fine sand, iron filings, urea, dung of horse, sawdust, etc. which are harmful.
Effects of food adulteration : The health is affected by food adulteration.
(3) Laws against food adulteration : Parliament passed the Prevention of Food Adulteration Act in 1954. This law has been amended from time to time. By the amendment of 1976, there is a provision of ‘life imprisonment’ for the person who does food adulteration with a harmful substance.
Directions of the law :
(1) Food should be properly stored
(2) Packing material should not endanger the food or medicines
(3) Clear and legible information should be there on packets about the manufacturing date, expiry date, and instruction for storage and handling.
Attempts of food adulteration :
(1) To make fruits more attractive and tasty some chemicals are injected into them. (2) Urea is added to the milk by milk vendors so that it appears as if having higher fat content.
(3) Expiry date of the food packets and air tight containers is changed by Shopkeepers because they want to avoid a financial loss.
(4) Calcium carbide and some other, chemicals are used to make fruits look more attractive, e.g. bright yellow bananas.
(5)Carbonate Soda, Phosphoric acid, etc. are mixed with cold drinks. These are very harmful chemicals.
Food Stuffs and Adulterants :
(1) Turmeric powder — Metanyl yellow
(2) Black pepper — Seeds of papaya
(3) Rava — Iron filings
(4) Honey — Water of jaggery
(5) Milk — Water, urea
(6) Red chilly powder — Brick powder
(7) Black pepper —seeds of papaya
(8) Ice cream — Washing powder, paper pulp
Organizations to look after food safety :
National Institutions -Food and Drug Administration
(1) FDA or Food and Drug Administration : FDA is a national government organization It controls production and distribution of food and drugs by their standardization.
(2) As per the Food Safety and Standardization Act-2006, food Safety and Standardization Authority of India (FSSAI) has been established. [/responsivevoice]
How will you find out if food has been adulterated?
| Food material | Adulterant | Test | Conclusion |
| Milk | Water | Put a drop of milk on a glass slide and slightly incline it to spread the drop. | If the spread-mark of milk does not appear milky white, water must have been added to it. |
| Red chilly powder | Brick dust | Take a spoonful of chilly powder in a beaker, add water up to half of the beaker, stir it and leave it undisturbed for a few minutes. |
If a red layer is seen settled at the bottom of the beaker, it must have been adulterated with brick dust. |
| Turmeric powder | Metanyl yellow | Take a pinch of turmeric powder in a test tube, add a small quantity of water to it, shake the mixture and add a few drops of conc. HCl. |
The mixture becomes red on addition of conc. HCI and the red colour does not disappear if metanyl yellow is present. |
| Rava | Fine iron filings | Pass a magnet through the rava. | Iron filings adhere to the magnet. |
Solution
Question 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 .......... .
(b) Materials like milk are instantly cooled after heating up to a certain high temperature. This method of food preservation is called .......... .
(c) Salt is a .......... type of food preservative.
(d) Vinegar is a .......... type of food preservative.
(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.
Question 2:
Answer the following questions in your own words.
(a) How is milk pasteurized?
Milk is pasteurised in order to kill any kind of harmful microorganism present in it and to increase its shelf life. Pasteurisation is a process in which the milk is heated to a certain temperature for a fixed period of time and then is quickly cooled. For example, it may be heated at 80oC for 15 minutes and then immediately cooled. This helps to kill any kind of microorganism which is present in milk.
(b) Why should we not consume adulterated food materials?
Consuming adulterated food may result into ill health. The various types adulteration affect our body in different ways. It may result into food poisoning or maycause abdominal discomfort. Some adulterants may affect the functioning of some organs. If contaminated food is consumed over a long period of time it may cause cancer. The adulterants which are added to food products have harmful effects on our bodies. For example: We should be very careful in buying our food products and should be aware of our rights and actions which can be taken against people who are involved in this crime.
(c) What precautions do your parents take to keep foodstuffs safe?
Precautions which are taken to preserve foods:
1. Storing fruits and vegetables in proper storage, for example, fruits like banana, are not stored in refrigerator while fruits like mangoes require refrigerator.
2. Storing grains, dals etc. in dry conditions and in air proof containers.
3. Making pickles and jams to increase their shelf life.
(d) How does food spoilage occur? Which are the various factors spoiling the food?
Food spoilage occurs due to many reasons: (1) The wrong and careless transportation of the food stuffs from the farm to the customer can cause food spoilage. (3) Some food stuffs have intrinsic factors which makes them perishable. Milk, meat etc. have acidic of (4) Chemical reactions occur in the food. Some are reactive to the metals and this results into production of harmful compounds. (5) Microorganisms from surrounding air, water and land enter the food and cause their deterioration
(2) Improper handling, storage and transportation leads to major spoilage.
alkaline contents which get spoiled soon.
Insects also attack and food and such infested food is bad for health.
(e) Which methods of food preservation would you use?
The following methods of food preservation can be used:
Question 3:
What shall we do?
(a) There are vendors selling uncovered sweetmeats in open places in the market.
We should not eat food from vendors who sell uncovered foods. We should try to talk to him and convince him to keep his food covered while selling it. Also, we should tell him the importance of clean and healthy food and how these habits can help him to gain profit for his business.
(b) A 'pani-puriwalla' is serving the pani puri with dirty hands.
We should make other people aware about the possible effects of consuming dirty panipuri. We should also tell the pani-puriwalla’ to clean his hands as he may infect many people with such contamination.
(c) We have purchased a large quantity of fruits and vegetables.
If we have purchased large amounts of fruits and vegetables, then we need to store them properly. Some of the fruits can be used to make juices, jams and jellies which would increase their shelf life and also make it easy to store food. Vegetables can be cut and stored in deep freezers and then used as and when required. Some vegetables can also be used in making pickles.
(d) We need to protect foodstuffs from pests like rats, cockroaches, wall-lizards, etc.
Foodstuffs can be protected from rats, cockroaches etc. by storing them in proper conditions and proper areas. They should be stored in air tight containers and away from damp places which are the breeding places for these organisms. The food stuffs should be stored in a safe and clean place. The place of storage should be clean, protected and covered. Keeping them in refrigerator or food-cupboard is a better way of protection.
Question 4:
Find the odd-man-out.
(a) salt, vinegar, citric acid, sodium benzoate
Salt is the odd one out beacuse it is natural preservative while rest of them are chemical preservatives.
(b) lakhi dal, brick dust, metanyl yellow, turmeric powder
Turmeric powder is the odd one out because it is a type of spice while the rest of the three are adulterants
(c) banana, apple, guava, almond
Almond is the odd one our because it is a dry fruit whereas the rest of the three are fresh fruits..
(d) storing, freezing, settling, drying
Settling is the odd one out because rest of the three are preservation methods.
Question 5:
Complete the chart below.
| S.No. | Foodstuff | Adulterant |
| 1. | ---------- | Metanyl yellow |
| 2. | Black pepper | ---------- |
| 3. | ---------- | Iron filings |
| 4. | Honey | ---------- |
S.No.
Foodstuff
Adulterant
1.
Turmeric powder
Metanyl yellow
2.
Black pepper
Papaya seeds
3.
Rava
Iron filings
4.
Honey
Sugar
Question 6:
Explain why this happens and suggest possible remedies.
(a) Qualitative wastage of food.
Wastage of food can either be qualitative or quantitative. Qualitative wastage of food is caused by: Qualitative wastage of food can be prevented by adopting steps like controlling the use of preservatives, taking care while cooking food to prevent it from being overcooked or under-cooked, using proper methods of storage etc.
(b) The cooked rice is underdone.
When the sufficient water is not added while cooking the rice, then it may remain underdone. If the cooked rice is underdone, it can be used to make some foodstuff in which it can be reused. For example, underdone rice can be used to prepare kheer in which it can be cooked further with milk, or it can further be cooked to make papads or something else which would avoid its wastage.
(c) The wheat that was bought is a bit moist.
The wheat bought from market may not have been stored properly. During rainy season when there is humid atmosphere, the wheat becomes damp. When the wheat is brought home, it may become damp due to faulty transportation. Remedy : The wheat should not be touched by wet hand. It should be dried in sun for four to five times. Then the dried wheat should be placed in clean, dry and airtight containers.
(d) The taste of yoghurt is too sour/slightly bitter.
Yoghurt is set by using the culture of previous curd. If this culture is bad, it may result into sour or bitter curd. If the yoghurt is stored for a long time, it may turn sour or bitter. Storing it at improper temperature also results into similar problem. Remedy : Throw the bitter yoghurt. If sour, it can be transformed into butter milk or add sugar to it.
(e) Cut fruits have turned black.
Cut fruits turn black due to oxidation. Small amount of lemon juice should be applied to the surface of cut fruits as it prevents the oxidation of the fruits.
Question 7:
Give reasons.
1. Food remains safe at 5° Celsius.
Food remains safe at 5oC because this temperature prevents the growth of microorganisms. Microorganisms usually require hot and humid places to grow whereas at this temperature they cannot grow and survive. Their metabolic activities are inhibited at this temperature.
2. Nowadays, food is served buffet style during large gatherings.
Nowadays, foods are served in buffet style during large gatherings to prevent the wastage of food. Every individual can choose what to eat and how much to eat according to their wish and thus prevents the wastage of food.
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