How to Measure Glucose in Food

Glucose is the simple sugar found in the bloodstream and it is an important source of energy for muscles and other tissues of the body. The glucose in your blood comes from the food you eat. Too little glucose makes your brain and other organs lack the sufficient energy they need to function; while too much glucose in the blood can cause diabetes, which is a serious and growing health problem in the U.S., according to the Science Buddies website. Glucose in food is measured with glucose-urine test trips, which are available in the market.

Things You'll Need

• Cups
• Distilled water
• Glucose-urine test strips
• Mortar and pestle or grinder

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Instructions

• 1

  Prepare your controls. The negative control should have no signal because it has no glucose and the positive control should have a clear signal showing that the glucose strips are working properly. To make the negative control, add tap water to one cup and label it as the negative control. Test it by inserting a test strip. There should be no change. The positive control comprises different concentrations of glucose dissolved in the same amount of distilled water. The concentrations need exact levels of glucose, for example: 0.1 percent, 0.25 percent, 0.5 percent, 1 percent and 2 percent. Make a series of five dilutions. Dip a test strip into each of the positive control solutions. Watch the test strip for 30 seconds (or the time recommended in the test strip instructions) and match the color of the test strip to the color on the bottle. Record your observations.

• 2

  Grind or crush a small amount of the food to be tested and put it into a cup to a depth of about 3/4 inch. Add a similar amount of distilled water and stir with a glass rod. Allow to stand for a few minutes. If the food is in liquid form, place the same amount in a cup. If you want to test viscous substances such as honey, dilute them in water.

• 3

  Dip the test trips in the liquid and immediately start the stopwatch. Wait for the amount of time specified in the strips' instructions, which varies depending on the brand but is usually 30 seconds. Record the color change of the strip. Compare the colors with the dilution series you made and record your results. Different strip brands use specific color matches for the glucose levels. Compare the color on the test strip with the color on the side of the container to determine the glucose concentration. Record your results. Repeat the process for all the food samples to be tested, for at least three trials each, recommends the British Nutrition Foundation.