A food sample is rubbed on the paper and it turns translucent. This indicates the presence of carbohydrates.
Is there any other test to test the presence of fats in a given substance other than pouring that substance into some paper like material and then seeing whether it turns translucent or not? Because if we even pour water or any liquid on that paper like material it also makes the paper turn translucent...
When copper sulphate and caustic soda are added to a food sample, a violet color indicates the presence of proteins in the food.