Food Tests

1. Food Tests Review Food Tests

2. Food Tests Food

3. 8A Food – who needs it? Energy to do things Raw materials to grow larger Raw materials to repair damaged body parts What do we need food for?

4. 8A So what’s in food? Proteins Fats Carbohydrates (starch and sugars) Roughage Vitamins Minerals Water Food is a complicated mixture of different chemicals. We can sort these chemicals into different types. What are the main types? Can you make up a sentence with words starting with the same letters – a mnemonic?

5. 8A Which food contains which chemical? Which foods belong to which food groups? Proteins Water Fats Carbohydrates Proteins Fats Carbohydrates Water

6. 8A What’s in food? Orangey-brown iodine turns blue-black when it reacts with starch. We can test foods to find out what chemicals they contain. drop iodine solution onto the food black = starch

7. 8A What’s in food? Blue Benedict’s solution turns orangey-red when it is boiled with glucose. blue turns orange/red= glucose chopped up food hot water heat

8. 8A What’s in food? In the Biuret test the solution turns purple. potassium hydroxide coppersulphate shake purple = protein chopped up food

9. 8A What’s in food? Fats go cloudy white when they are mixed with ethanol and water. add water filter grind food with ethanol cloudy = fat Now see if you can use these tests to identify the food chemicals on the next slides.

10. 8A What’s in food? For each food, decide on the chemicals found in them. Protein Fats Starch Glucose

11. 8A What’s in food? For each food, decide on the chemicals found in them. Protein Fats Starch Glucose

12. 8A What’s in food? For each food, decide on the chemicals found in them. Protein Fats Starch Glucose

13. 8A What’s in food? For each food, decide on the chemicals found in them. Protein Fats Starch Glucose

14. 8A Vitamins Liver, butter, green vegetables Healthy skin and teeth A Healthy skin Cheese, milk, liver, eggs, green vegetables B2 Citrus fruits, green vegetables, potatoes Healthy teeth and gums, without it you get scurvy C Fish liver oil, eggs, sunlight on the skin Healthy bones – without it you get rickets (soft bones) D