After a lesson on starch, we tested for its presence in foods that we eat (cheese, rice, crackers, cucumber, potato, and flour). Iodine (brown color) will turn blue black when starch is present. Our biggest surprise? The cheese turned dark blue. After checking the ingredients, we discovered that potato starch was added to the grated cheese. I researched why it was added and found that it is used to prevent clumping.
We learned that oxidation occurs when an apple is cut open and the tissue is exposed to oxygen. Rust is also the result of oxidation. The lesson continued with information about how oxidation occurs within our bodies. We discussed the importance of a diet rich in antioxidants.
Many of the children had observed apples turning brown. Our experiment focused on determining the best liquid to prevent oxidation. We used the scientific method and had a control in this experiment. We concluded that we had the best results with salt water. Some of the children were surprised that the lemon juice did not work better because they had observed parents use lemon juice to prevent oxidation at home. We added a teaspoon of lemon juice to a cup of water. We may have had different results with more lemon juice. Apple juice and Ginger Ale also had positive results.