Test glucose content

[bumblebee27]

Hi,

I would like to test glucose content of different variety of rice. I am thinking of using brown rice, parboiled rice and Basmathi rice. Which is the best way of doing this. I looked at http://www.sciencebuddies.org/science-f ... p049.shtml

How can I modify the above experiment to use for my rice project?

Any help is appreciated.

Regards

Vish

[heatherL]

Hi Vish,

You absolutely can modify the "How Sweet It Is" project to measure the glucose contents of different varieties of rice. Keep in mind that the differences in glucose content *could* be very small, so they may or may not be detectable with the test strips. Also keep in mind that the test strips only work in liquids, so you will need to find a way to liquefy your rice. I suggest cooking the rice (with the same ratio of water to rice for each type), using a blender or food processor to mash up the cooked rice, and then diluting the rice further (again, the same amount for each type) to create a liquid mixture.

All varieties of rice are based on carbohydrates. Do you have any predictions for the differences in glucose content based on your background research? Do the different varieties of rice have different sugar totals listed on their nutrition facts?

I hope this helps! Please post again (in this same thread) if you have more questions.

Heather

[bumblebee27]

Hi Heather,

Happy New Year!

Thanks for your response. I am planning to test Brown Rice, Basmati and long grain rice. Based on research I think brown rice will have less Carb. The basmati and long grain show zero grams of sugar whereas the brown rice shows 1 gm. Does the level of Carb matters or the sugar content matters. I was surprised to see 1 gm of sugar in the nutritional information for brown rice. I had earlier planned to do Glycemic Index but could not get volunteers to test blood sugar so doing the glucose project. My main concern is to find which rice is best for people with Diabetics. With this info do you think the glucose test is the right way to proceed?

[heatherL]

Hi Vish,

Happy New Year to you, too!

Thanks for providing the additional information. It is interesting that you want to relate the amount of sugar in the rice to its effect on people with diabetes. I think that glycemic index is a much more accurate way to measure this, as different carbohydrates (and other foods) can still increase blood glucose. Check out this information from the American Diabetes Association: http://www.diabetes.org/diabetes-basics/diabetes-myths/, http://www.diabetes.org/food-and-fitnes ... -counting/

Your measurement will only be detecting glucose. If you are interested in the total amount of carbohydrates in your rice, you might try using a different test. Here is some information for testing total carbohydrates in food: http://people.umass.edu/~mcclemen/581Carbohydrates.html. This is a much more complicated analysis, so you may not want to go that route. But you do need to understand that it is not just glucose itself that causes blood glucose to rise after eating. I do think that glycemic index is the best way to directly test what you are interested in.

Here is the Wikipedia article regarding the glycemic index: http://en.wikipedia.org/wiki/Glycemic_index. Although Wikipedia is not considered a reliable resource, it's a good starting place and the bibliography usually has a lot of great resources.

I hope I have not discouraged you. Your project idea is still interesting in its own right. You could test the glucose content of the different kinds of rice, and still talk about how that relates to the total amount of carbohydrate in each type. The American Diabetes Association points to the total carbohydrate as a risk factor, over any other measure. But it is interesting that brown rice contains more sugar, whereas the other kinds of rice have more starch.

If you wanted to change your project a bit, you might consider testing the glucose content of different types of food with different (known) glycemic indices. Then you could see whether glucose content and glycemic index are related, and how.

Please post again if you have more questions!

Heather

[bumblebee27]

Hi Heather,

Thanks for your reply. I am thinking of doing the Glycemic Index. My parents are willing to volunteer. I am not sure with just 2 people it will be a good data. I am trying to get one another volunteer.

Meanwhile, I was planning to cook the rice the same way and have the volunteer eat it first thing in the morning and test the blood sugar after 2 hours.

Regards
Vish

[heatherL]

Hi Vish,

I think looking at glycemic index will make your results more applicable to diabetes.

Who will be drawing the blood? Since you are thinking about working with human subjects, you should be aware that there are guidelines you will need to follow. Here is some information about that: http://www.sciencebuddies.org/science-f ... ects.shtml

A sample size of two is very small. It would be good to get at least 5-10 volunteers, if possible. I assume that each person will be eating all three types of rice, each type on a different day.

I think it is also important to look at baseline blood sugar (before the rice is eaten). While it is good that you plan to have them eat the rice first thing in the morning, it's important to note that each person may be starting with a different blood sugar level. Since you are interested in the elevation of blood sugar, it would be important to measure the starting value each time.

Best,
Heather

[bumblebee27]

Hi Heather,

Thanks for your reply. I have now 4 people volunteer for the project. I was planning to measure with a known food the first time on day one. Then test the different variety of carbs. I am considering if I should just do rice or carbs. The people who volunteer also eat noodles so they want to know about that food as well.

For testing for carbs, I would first test the blood sugar before they eat the food and then after 2 hours as per your suggestion. Planning to do this 3 times for the same food on different days and continue with 3 -4 different carbs( Rice and noodles). Feeling bad that I have to poke them multiple times.

My father is going to help me in the testing.

I also submitted a SRC approval to the local Science Fair organization and waiting for approval.

Please let me know if I need anything else.

Regards
Vish

[heatherL]

Hi Vish,

Sounds great! The only other suggestion I have is that you test the different foods in a random order. In other words, mix up the order in which each subject eats the different foods.

Otherwise, it sounds like you are on the right track. Let me know if you have any more questions along the way.

Heather

[bumblebee27]

Thanks Heather.

I have these foods selected for testing.

Foods that we will Test: ( 50 gms of test food and 250 ml of water)
White rice
Pasta
Mashed potatoes
Brown rice
Corn

Let me know if you have any suggestions.

Planning to do the reference food ie White bread starting this Saturday. For this I had planned to test the blood glucose before the start of the test, and at 1 hour after the volunteers had the food and again at the end of 2 hours so I can get an AUC for the reference food. I suppose I might have to take the average AUC of the reference food of the volunteers to use later for calculating the GI of test food.

I looked at how it is done at http://www.nature.com/ejcn/journal/v61/ ... gure-title

Regards
Vish

[heatherL]

Hi Vish,

Looks like you are on your way! Good job locating a scientific reference for your methods.

Note that the article states "The test food and reference food (usually 50 g glucose) must contain the same amount of available carbohydrate." It is important to look at the available carbohydrate in the food. In other words, the technical way to standardize the measurements would be to compare foods at 50g of carbohydrate (not 50g of the food itself). However, as long as you are consistent with your measurements, it could still work.

From what I can tell, you take the AUC for your reference food (just until it hits the baseline), and then you report the glycemic index as a percentage of the reference AUC. So you don't really need an average. The idea is to use each person as his/her own control.

Keep up the good work, and please continue to keep me posted on your progress!

Heather

[bumblebee27]

Hi Heather,

Thanks for your reply. How do I measure 50 gms of carb in a food. Do I use the Nutritional info.

Regards

Vish

[heatherL]

Yes, you can use the food label to determine the number of carbs. Remember that the label tells you the grams of carbs per serving, so you'll need to look at the serving size and multiply (or divide) accordingly. The American Diabetes Association explains it at the bottom of this page: http://www.diabetes.org/food-and-fitnes ... -counting/

You might have a harder time with fresh corn, but canned corn should have a nutritional label you can use.

Remember to have your subjects fast (not eat for 12 hours) before each test, so that the only thing in their stomach is the food and water you give them. The easiest way to do this is to have them do the test first thing in the morning, before they eat breakfast. No juice or coffee before the test, either!

Heather

[bumblebee27]

Thanks Heather,

I was about to post this link which i found

http://www.diabetesnet.com/food-diabete ... bohydrates

Regards

Vish

[heatherL]

Excellent! You're on your way.

[bumblebee27]

Thanks Heather.

I did the reference food and one test food during the weekend. Seems each individual has a lot of variation for the same food. I am still wondering how the GI would be common across different people.

Thanks once again.

I will keep you posted.

Regards
Vish