Science Buddies: "Ask an Expert"

Hi, I want to do an experiment relating to perhaps the benefits of buying organic labeled food versus conventional foods. What experiments could I do relating to the prices of both types of foods, or consumer perception of those prices.

Another experiment I could do is observing advantages of organic food, or perhaps disadvantages, through means of food chemistry. But I am having a hard time finding original hypotheses or a way to test the nutritional/physical components of the organic/conventional food. Any ideas? Thanks!

Hi diamond_star,

You have some very interesting ideas, which are quite relevant in today's food market!

It would be a fairly simple thing to research the prices of similar foods (organic vs. conventional) in a number of grocery stores to see how they compare, and to do a survey to see if people's perception of the prices matches the reality.

Here is some information and tips from Science Buddies about how to design an effective survey:
https://www.sciencebuddies.org/science- ... rvey.shtml
https://www.sciencebuddies.org/blog/201 ... eysays.php
https://www.sciencebuddies.org/science- ... ants.shtml

Another way to go would be to test for different chemicals present on organic and conventional foods. It is a common misconception that organic foods do not use any chemicals, so it would be interesting to see what you can detect.

I hope this helps you get started. Please post back if you have more questions!

Heather

Thanks for for the reply!
I was wondering whether there was a simpler way of conducting a survey, as it would be difficult to get surveys from shoppers at grocery stores.
Is there a way to develop an experiment by comparing organic food prices, such as purchasing organic vs. conventional products (same type of foods) under a certain budget, and observing whether organic food may just be affordable, how its advantages outweigh the disadvantages, or other matters that focus on what the consumer gets out of organic food vs. conventional/its long-term benefits? I know it would be difficult to look at all these questions in one experiment, so I'll narrow the scope of it later on.

And as for the other idea, what methods could I use to test for pesticide residue and the amount of it?

Hi diamond_star,

It would be difficult to get surveys from random shoppers at grocery stores. However, you could conduct a survey of your classmates' parents, who probably shop for produce. Your sample would not be biased going into it, since you don't know about your classmates' parents' preconceived notions regarding organic foods. That might be a good option for you.

Your idea regarding price comparisons sounds more like research than an actual experiment. It might be a good idea to compare prices anyhow, so you can see whether your survey-takers' perceptions of the pricing is accurate.

Others have considered testing for pesticides, and your best bet is probably to find a kit to purchase online.
Here are links to previous Ask An Expert discussions of the topic:
https://www.sciencebuddies.org/mentorin ... =28&t=7595
https://www.sciencebuddies.org/science- ... =28&t=7918

Here are some links I found to potential kits you can purchase. Please look through the reviews and such before you purachse something!
http://www.google.com/products/catalog? ... CHYQ8wIwAA
http://www.google.com/products/catalog? ... CHwQ8wIwAQ
http://www.google.com/products/catalog? ... IIBEPMCMAI

Let me know if you have further questions.

Heather

I was wondering if I could test for pesticides in processed foods, such as chocolate or bread, to see if organic snacks are better alternatives than the conventional kind.

Here is the link I found:

http://www.foe.co.uk/resource/briefings ... s_food.pdf

Thanks

Hi diamond_star,

If you really want to get into the pesticide testing idea, I suggest that you contact a local college or university to see whether they have a laboratory that could help you with that analysis. Testing for pesticide residues in fruits can be done with an at-home kit because you can rinse the fruit into a glass and test the water in that glass. Testing processed foods is a more complicated process, and probably requires the help of a lab.

I hope that helps. Keep us posted with your progress!

Heather

I am actually going to see the rate that organic apples give off ethylene gas compared to conventional. I plan on doing this by placing it in a container with bananas and observe the effects of ripening. ANything I should consider? Thanks!

What a cool idea!

One thing to consider is that bananas give off a lot of ethylene gas on their own. Make sure you use the exact same type of banans, so they don't influence the differences you observe. You might also consider comparing organica and conventional bananas to each other (just put each type in its own bag).

When you observe ripening, make sure to take as many notes as possible in terms of observations, and be consistent!

Let us know if you have more questions as you set up your experiment.

Have fun!
Heather

Hello,

The idea was already taken.

I am now planning to observe the ripening effects of organic bananas vs. conventional bananas. Does this seem like an original idea?

https://www.sciencebuddies.org/science- ... p&from=TSW

Also, since I don't have access to a refractometer, would glucose test strips or meters be sensitive enough to detect glucose change. Or where else can I obtain a refractometer in the next few days?

Thank you!!

If I do purchase one, should I get the one with ATC?

Sugar Refractometer 0-32% W/ATC by Sper Scientific
http://www.amazon.com/Sugar-Refractomet ... B001F07ZAC

Sugar/Brix Refractometer 0-32% by Sper Scientific
http://www.amazon.com/Sugar-Refractomet ... roduct_top

Thank you!

Worst day ever:

- Did loads of research
- Bought 100 glucose strips and meter (about $100)
- Tested with bananas-->DIDN'T WORK

Any way to return this costly equipment, only opened one of the two cases of the glucose strips?!

Hi diamond_star,

I am sorry to hear your experiment did not go as planned.

With regard to returning the equipment, I suggest you contact Amazon (or the seller directly, if applicable).

What exactly didn't work? Were you unable to detect differences, or did the equipment not function properly? If you were unable to see differences, that is still an interesting result! Can you give us more details about what happened?

Heather

Hello! Its been a long time, mainly because I became so busy, but I finished the project a couple weeks ago! Everything is fine now!

As said earlier, I was originally going to measure the change in glucose levels on ripening bananas (organic vs. conventional) over a period of days, assuming that the glucose meter was going to work. So I got these glucose strips (it had this special metal material) and a electronic glucose meter. It was very expensive, around $90, as we had no diabetic purposes for the equipment that could have been covered by insurance. But since I was tight on time, I had to get them (since I wanted to present my experiment early so I would not have to show up for class during exam week, thus I had approximately two weeks).

Also, I got 24 light green (ripe) bananas, around $10 for 4 clusters. Not wanting to work with a lot of bananas, I decided to measure the glucose change every 2 days three times (so 6 days).

When I tested it at home, there was no signal on the meter when I put a bit of the banana mush on the glucose strip. This made me panic! I felt like I was not going to make it in this experiment since I was losing time.

But finally, I told my dad that I would need a refractometer, as mentioned in one of the science buddies experiment ideas. The problem was that there were barely any stores that sold sugar refractometers. The only likely place would have been Home Depot, but a) I read this on the Web and it said "Online Exclusive" so I really wasn't sure whether it was available at the nearest store; and b) I was unsure whether it really was meant to measure sugar.

So later my dad ordered found and ordered a sugar refractometer on Amazon (about $40) and signed up for some membership that would have the product be shipped the next day. Thankfully, the instrument was fine when it came two days later, but during those days I was kind of losing hope.

So now with a refractometer, I changed my experiment from measuring glucose to measuring sugar content. The experiment worked out fine though measuring would take 2 hours a time. And the journal, paper and powerpoint presentation costed me around 5 hours to do. I was getting worried that it would impact my preparation for my exams, especially the crucial ones. But in the end, I felt relieved after finishing my presentation to my reaserch class. I guess it was worth it as I so far have gotten all A's on 4 of my exams, but I feel pretty confident about the others as I didn't really need A's in those.

But just when I though I had FINISHED, my teacher said that my expriment was sudo-sampling because the bananas I got from Giant (the Chiquita brand) were from the same banana tree plant. So I have to repeat the experiment 2 more times (18 bananas each time as I did for the first time). So hopefully everything works out. And, oh yeah, the science fair.

Thank you for your help and patience with my posts! This experiment had been a meaningful, despite hectic, experience.

Hi diamond_star,

I'm glad to hear everything is fine, and especially glad to hear that you earned A's on your exams!

Your teacher was referring to something called pseudo-replication, which happens when you think that your samples (in this case, the bananas) are independent but in fact they are not. Because your bananas came from the same bunch, you can not treat each banana as an independent sample; we would expect them to have similar glucose contents because they are genetically related. So if you repeat your experiment with bananas from different trees, you will get a large enough sample size to compete in your science fair.

Please let us know if you have any more questions along the way. As you have seen, science can be frustrating; but the learning experience can be rewarding!

Best,
Heather