What is food made of? Components and classification
Food is anything we eat or drink to stay alive and healthy. Every food is made of up to six components: carbohydrates, proteins, fats, vitamins, minerals and water. Foods differ only in how much of each they hold. Rice is mostly carbohydrate. Egg is rich in protein. Butter is mostly fat.
We classify (sort) foods in many ways. The most useful way for study is by source and by how much people have changed the food:
- Plant foods and their processed products
- Animal foods and their processed products
- Extracted components: one part taken out of a food
- Seasonings, sweeteners, spices and drinks (luxury foods)
Other ways to sort: by the main nutrient (energy foods, body-building foods, protective foods) or by how fast the food spoils.
Plant foods and processed products
Plant foods come from seeds, roots, stems, leaves and fruits. The main kinds are:
- Cereals (rice, wheat, maize): mostly starch, the main energy food.
- Pulses and soya (dal, beans): good plant protein.
- Potatoes and roots: starch.
- Vegetables and fruits: vitamins, minerals and fibre, with lots of water.
- Nuts and oilseeds: fat and protein.
Processed plant foods are made by grinding, cooking, fermenting or drying: flour from wheat, noodles from flour, tofu from soya milk, dried fruit, pickles.
Animal foods and processed products
Animal foods are milk, eggs, meat, poultry and fish. They give complete protein (all the protein parts the body needs), plus fat, vitamin B12 and iron or calcium. Milk and eggs come without killing the animal, so they suit vegetarians who eat them.
Processed animal foods: curd, paneer, cheese and butter from milk; dried or canned fish; sausages and ham from meat. Processing makes the food last longer or changes its taste.
Extracted-component materials
Sometimes factories pull out just one component from a food and use it alone. Examples: oil pressed from seeds (fat), sugar from sugarcane (carbohydrate), starch from maize or potato, protein powder from milk or soya, gelatin from animal bones and skin, and pectin from fruit peel.
These are used as ingredients: oil for frying, starch to thicken, pectin to set jam. They are concentrated, so a little goes a long way.
Seasonings, sweeteners, spices and luxury foods
This group is eaten for taste and pleasure, not mainly for body fuel.
- Seasonings add taste: salt, vinegar, soy sauce, miso.
- Sweeteners add sweetness: sugar, honey, jaggery.
- Spices add flavour and colour: turmeric, chilli, pepper, cumin.
- Luxury foods and drinks (also called stimulant or pleasure foods): tea, coffee, cocoa, and soft drinks. Tea and coffee contain caffeine, which wakes the brain up.
We use them in small amounts. Too much salt or sugar can harm health.
Try it: sort your kitchen
Ask an adult to let you look at 10 things in the kitchen. Write each one in a box: Plant, Animal, Extracted or Seasoning. Then pick 3 and write whether it is raw or processed. Predict first: which box will have the most items? Then count.
Key formulas and definitions
- Six components: carbohydrates, proteins, fats, vitamins, minerals, water
- Four groups (PAES): Plant, Animal, Extracted, Seasoning and drinks
- Raw food + processing = processed food (flour, curd, tofu, cheese)
- Extracted component = one part pulled out (oil, sugar, starch, protein powder)
Worked examples
1. Put these in the right group: wheat, egg, sugar, turmeric.
Wheat: plant food. Egg: animal food. Sugar: extracted component (from sugarcane). Turmeric: spice (seasoning group).
2. Milk is an animal food. Name two processed foods made from it and say which group they belong to.
Curd and cheese (or paneer). They are processed animal foods because they are made from milk by changing it.
3. Is cooking oil a plant food, an extracted component, or a seasoning? Explain.
It is an extracted component. Factories press the fat out of seeds like mustard or groundnut and use only that part.
4. Why is tea called a luxury food and not an energy food?
Tea is drunk for taste and the lift from caffeine. Plain tea has almost no carbohydrate, protein or fat to fuel the body.
5. A pack says: wheat flour, salt, oil. Name the group of each ingredient.
Wheat flour: processed plant food. Salt: seasoning. Oil: extracted component.
Common mistakes
- Thinking processed food always means unhealthy. Flour, curd and tofu are processed and perfectly healthy.
- Putting sugar or oil in plant foods. They come from plants but are extracted parts, so they get their own group.
- Saying egg and milk are plant foods because we do not kill the animal. They still come from animals.
- Forgetting that every food holds all six components. Foods only differ in how much of each.