Alpha science classroom： Test Your Foods for Starch

Have children heard of starchy and non-starchy foods? What is the difference between them? Starch-containing foods contain carbohydrate starch, which is converted into sugar (glucose) in our body and used to produce energy. How do children know which foods contain starch and which do not? Today, Alpha Science Class passed the "Test the Starch in Your Food" activity, and learned how to test starch through chemical tests in this fun children's chemistry experiments activity. We hope that this kid's science experiments activity can help children learn simple chemistry and explore more scientific mysteries.

Alpha science classroom: Test Your Foods for Starch, required materials

• Tincture of iodine or a solution (2%) such as the kind used in first aid kits as an antiseptic for small wounds

• Corn starch

• water

• Cups (2)

• Knife

• Cutting board

• 1/4 teaspoon

• Aluminum foil

• Straw or dropper

• Safety glasses

• Optional. An apron

• A variety of foods, such as.

• Potatoes

• Pasta

• Vegetables

• Fruits

• Cookies

• Candy

• Optional. Microwave oven

• Optional. Refrigerator

• Optional. Liquid foods or beverages such as yogurt, juice, or milk

Alpha science classroom: Test Your Foods for Starch, step-by-step tutorial

alpha science classroom tips

This chemistry experiment for children requires children to wear safety glasses and open the iodine solution carefully. Note that iodine can stain your countertop or clothing, so handle with care and try to avoid any spills. You can wear an apron to protect your clothes from potential spills.

Step 1: First, children suck up some of the iodine solutions with a straw and think about what color the solution has.

Step 2: Children carefully add a few drops of the iodine solution to a glass with only water. Think about it. What do you notice? How does the color of the water change?

Step 3: Children drop a drop of iodine solution right through the tip of the pipette into a cup of water. Next, add a few drops of iodine solution to the cup with water and cornstarch. What happens when you add iodine? How are your results different from before?

Step 4: The children will now begin testing the food. Use a knife to cut off a small piece of each food you want to test. Place these pieces of food on a piece of aluminum foil next to each other.

Step 5: The children use a straw to suck up more of the iodine solution. Place a drop of the iodine solution on the first food you want to test.

Step 6: The children wait about 1 minute and observe what happens. Think about it. Did you notice any change in color after adding the iodine solution? Can you explain your results?

Step 7: The children lay various pieces of food on a sheet of aluminum foil. Hold a piece of apple in one hand with a drop of iodine solution on it.

Step 8: The children continue testing other foods by putting a drop of iodine solution into them. Think about it. How can you tell from your results which foods contain starch and which do not?

Alpha science classroom: The Science of Test Your Foods for Starch

Starch is a carbohydrate that is a major component of many foods, such as bread, potatoes, pasta, or starchy vegetables. It is made up of two main components called straight-chain starch and straight-chain starch. Maltose is a long, linear chain of glucose molecules that forms a spiral that looks similar to a coiled spring. Glucose is a simple sugar that many organisms need to produce energy for themselves. Straight-chain starch also consists of chains of glucose units, but the structure of straight-chain starch is not linear like straight-chain starch but branched. Because of its branched structure, straight-chain starch is completely insoluble in water, while linear straight-chain starch is partially soluble in water. Many plants make starch and store it as granules, by converting it into glucose and using this starch as an energy source at night. The greatest application for starch, besides the manufacture of food products such as pasta or cereals, is paper production. For example, a typical piece of copy paper may contain up to 8% starch.

Alpha science classroom tells children that, as you may have noticed in this activity, iodine can be used to detect the presence of starch in food or other objects. The color of the iodine solution is orange-yellow. When you add the iodine solution to water, the color should remain essentially the same. The color may lighten a bit due to dilution, but the water should still be orange-yellow in color. When you make the starch solution in the second cup, it should look like a cloudy white solution. The solution is cloudy because cornstarch is partially insoluble in water. When you add iodine to the cornstarch solution, you should notice that the liquid in the cup turns dark blue or almost black almost immediately. The color change occurs because the iodine reacts with the starch to form a dark blue starch/iodine complex.

The same reaction occurs when you add the iodine solution to food containing starch. You may have noticed that iodine solutions change color when you put them on foods that contain a lot of starch, such as pasta, potatoes, or certain crackers. Other foods - such as peppers, cucumbers, and strawberries - are non-starchy foods, and when you add iodine solution to these types of foods, it should not change color.

If you heat a cornstarch solution with iodine, you may notice that the dark blue color of the starch/iodine complex disappears as the temperature increases. This is because the starch/iodine complex is not stable at higher temperatures. When the complex falls apart and dissociates, its color disappears.

Now the children understand the role of starch! Starch, as a kind of carbohydrate, is also one of the most important sources of energy for human beings. Only by constantly ingesting this kind of food can we grow and live healthily. Children must eat obediently in the future! Well, today’s alpha science classroom is over. I hope that this interesting children’s chemistry experiments activity can bring scientific inspiration to children so that children can fall in love with kid’s science experiments activities, explore more wonderful scientific knowledge, and become The most powerful scientist.

Similarly, alpha science toys have prepared interesting children's chemistry experiment kits for children, so that children can explore the magical science mysteries and learn knowledge happily at home.