(BIO) How can we know what food substances are in the food?

We can know that through tests.

Test for Carbohydrate:::
1) Drop some iodine solution on the food
2) If the iodine solution turns from brown to dark blue, then the food contains
carbohydrate.

Test for glucose::
1) Put a piece of clinistix paper on the food solution
2) If the clinistix paper turns from pink to purple, then the food contain
glucose.

Test for protein::
1) Put a piece of albustix paper on the food solution
2) If the albustix paper turns from yellow to green, then the food contains
protein.

Test for fats:
1) Drop a spot of water on the filter paper as a control.
2) Drop a spot of food solution on the filter paper
3) Wait for a few minutes.
4) Observe the filter paper
5) If the spot of food solution is transparent, then the food contains fats.