Food scientists can test for starch in food using iodine solution. If starch is present, the iodine will turn dark blue. Testing for sugar can be performed with Benedict's solution. The Benedict's solution is added to the sample, and heated for five minutes.

Iodine is used to test the presence of starch in the food.

Explanation:
Iodine is a chemical element that is commonly used in various laboratory tests. One of its uses is in the identification of starch, a complex carbohydrate, in food samples. This test is known as the iodine test for starch.

How does the iodine test for starch work?
The iodine test for starch is based on the reaction between starch and iodine. Iodine molecules are able to form a complex with starch molecules, resulting in a dark blue color. This reaction occurs because the iodine molecules fit into the helical structure of starch, forming a stable complex.

Procedure for the iodine test for starch:
To perform the iodine test for starch, the following steps can be followed:

1. Take a small amount of the food sample to be tested.
2. Add a few drops of iodine solution (commonly known as Lugol's iodine) onto the food sample.
3. Observe the color change in the sample.

Interpretation of the iodine test for starch:
- If the food sample turns dark blue or black, it indicates the presence of starch. This color change occurs because the iodine molecules form a complex with the starch molecules.
- If the food sample remains the same color (usually brown or yellow), it indicates the absence of starch.

Why is the iodine test used to test for starch?
Starch is a common component of many foods, such as potatoes, rice, bread, pasta, and cereals. It is an important source of energy for the human body. By using the iodine test, we can determine whether a particular food item contains starch or not. This information can be useful for dietary purposes or for identifying the presence of starch in certain food products.

Conclusion:
In conclusion, iodine is used to test the presence of starch in food. The iodine test for starch is based on the reaction between iodine and starch, resulting in the formation of a dark blue complex. This test helps in identifying the presence or absence of starch in food samples.

Starch