Summer is over, and the days of the best fresh fruits are behind us for now. However, thanks to a global economy, we can still get delicious fruit from other warmer climates at our local grocer. So, even though it’s fall and the focus is usually on all things pumpkin, today, we’re going to break stride and try our hand at a fruity experiment.

Background

We’ve done several glucose test strip experiments here on the blog, so by now you know, glucose is a simple sugar, which acts as a significant energy source. It is the simplest form of carbohydrate, known as a monosaccharide. Glucose is also known as blood sugar, and it plays an important role in our body’s function.

How does our body process glucose? When we eat, our body immediately starts breaking down the glucose with enzymes and help from our pancreas. The pancreas produces insulin and other hormones to handle the rising blood sugar levels.

We all know that too much sugar is bad for us, but we do need some in our bodies. Fruit is an essential part of our diet, but too much can be a bad thing. Today, we’re going to experiment with the glucose levels in different types of fruit. This can help us determine what fruits we don’t need to eat as much of or what fruit juice we should maybe steer clear of.

Materials

Procedure

  1. When you select your fruits, try to select those that might be easier to get juice from. Some examples might be watermelon, oranges, grapefruit, or pineapples. If you have a juicer or a blender, you can get a little more creative with apples, blueberries, strawberries, blackberries, raspberries, etc. Hypothesize which fruits you think will have the most glucose and which will have the least.
  2. You’ll need a cup for each type of fruit. Squeeze some of the juice from the fruit into the cup. If the juice is thick or if its color is strong enough to dye the test strip, you may want to dilute it with some distilled water. If you do this, just be sure to measure out the amount of water very carefully and consider this dilution when calculating your results.
  3. You will need one test strip for each type of fruit. Dip the test strip into the juice for a couple of seconds, remove and run the strip along the edge of the cup to remove excess juice. Wait 3 minutes before comparing the test strip to the included color chart. Record your results for each type of fruit juice.
  4. Review your results. Was your hypothesis correct? Were there significant differences in glucose levels amongst any of your fruits? Why do you think this is the case? Were you surprised by any of the results?