These DAV Class 5 Science Notes and DAV Class 5 Science Chapter 6 Notes – Spoilage and Wastage of Food and Food Preservation act as excellent revision resources, particularly in preparation for board exams.
Spoilage and Wastage of Food and Food Preservation Class 5 DAV Notes
Common Household Practices To Prevent Spoilage Of Food:
→ Fruits and vegetables are usually placed in the lower shelves of refrigerator; if they have to be used after a few days.
→ Milk is boiled before storing. Milk packet/bottle is stored in refrigerator.
→ Biscuits, chips, pulses, uncooked rice, etc. are stored in jars/boxes at room temperature. Some people place turmeric powder or some other insect repellants in pulses and rice to prevent attack from pests.
→ Raw chicken, fish, etc. are immediately cooked or kept frozen.
→ Onions and potatoes are stored in the kitchen in trays or shelves at room temperature.
→ Sugar and salt are kept in containers at room temperature.
→ Curd is prepared at room temperature. It is then kept in refrigerator or used as soon as possible.
→ Signs of Spoilage of Food: Some food items; like milk, curd, eggs, fruits and vegetables get spoiled in a few days if they are kept at room temperature. This is shown by change in appearance, smell and taste.
Causes Of Spoilage Of Food:
→ Microorganisms: Organisms which are too small to be seen by naked eye are called microorganisms. Bacteria and fungi are examples of microorganisms.
→ They are the main cause of food spoilage. These organisms grow fast when they get proper temperature, moisture and food.
→ Preventing the growth of microorganisms in food: For this, we need to follow these steps:
- Remove moisture from the food; by drying the food item.
- Keep the food at low temperature (in the refrigerator).
→ Enzymes: These are the chemicals present in all fruits and vegetables. These enzymes cause ripening of fruits. But they also speed up chemical changes in fruits which results in loss of flavour, colour and appearance. Thus, enzymes can spoil fresh fruits and vegetables. Insects, worms and rats: These animals usually live in our surroundings. They can contaminate the food items. So, it is necessary to keep the cupboards, shelves and containers clean and dry. This prevents the pests from making a home in the kitchen.
Prevention Of Spoilage Of Food:
Following methods can help to prevent food from getting spoiled.
→ Milk, meat, fruits and vegetables are perishable food items. They should be kept in refrigerator.
→ Spices, cereals, biscuits and other snacks should be kept in airtight containers. Airtight containers prevent moisture from entering the food items. Shelves and cupboards should also be kept clean and dry.
Food Preservation:
The process of treating and handling of food to stop, or slow down, the spoilage caused by microorganisms is called food , preservation.
→ Importance Of Food Preservation:
- It helps in maintaining the nutritive value of food.
- It increases the shelf life of food. Thus, it improves the supply of many food items.
- It helps in making seasonal foods available throughout the year.
- It reduces wastage of food,
- It helps in adding variety to the diet.
Many food items which do not grow in our country can be obtained because of food preservation.
Wastage Of Food:
→ Many people take too much food in their plate; especially during a party. They end of throwing away most of the food. This results in wastage of food.
→ Many poor people go without food for many days. So, we should take every step to prevent wastage of food. We should take in our plate only as much food as we are going to comfortably eat.
→ Food Preservation: Treating the food to slow down its spoilage is called food preservation.
→ Dehydration: Process of removing moisture from a substance.
→ Enzymes: Chemicals present in fruits and vegetables.
→ Microorganisms: Tiny organisms which cannot be seen by naked eyes.
→ Pasteurisation: Pressurised heating followed by immediate cooling of food item.