The Water Content of Fruit (: helpmeplease!

[pamsername]

Hi, nice to meet you! Hows it going?

Well, anyways, I am feeling pretty stressed right now. First, for my assignment, I am to make an experiment on the following topic:
Investigate the water content of fruit.

So far, I have done my research and have made a method. But I am having a lot of trouble with my hypothesis.
My research also is a little bit iffy, and I am not sure if I can get a hypothesis out of it.
RESEARCH:
· Certain fruits have relatively low water content (bananas, avocados).
· Most fruits have high water content.
· There are a variety of different types of fruits, including:
Berries - blueberry, raspberry, strawberry
Citrus - grapefruit, lime, lemon, orange, tangerines
Melons - honeydew, rockmelon (cantaloupe), watermelon
Stone - apricot, cherry, nectarine, peach, plum
Tropical - banana, mango, papaya, pineapple
Others - apple, dates, figs, grapes, pear

With this research, I have gotten 2 very confusing hypotheses:
Most fruits contain more water than solid content.
Most fruits have a higher water than solid percentage.

Do you get it? Its like, in a fruit, the weight will be more of water than its seeds & skin and stuff.
Y'know?

PLEASE, HELP ME FIGURE OUT A HYPOTHESIS!!
or, you can tell me if my hypothesis is relevant to my topic&research and is alright.

Thanks, hoping everyone has an awesome day (:

[geoffbruton]

Hi pamsername,

Welcome to Science Buddies! It sounds as though you have already made a great start in your background reading and research. Did you get a chance to read the hypothesis section of the Science Fair Project Guide? This should give you some indication as to how best formulate your hypothesis. It can be found at: https://www.sciencebuddies.org/science- ... esis.shtml The way in which you phrase your hypothesis is key, since it should make a statement that is testable. (In your project, this is definitely the case!)

Now, as for your apparently conflicting research, I actually think you already have the answer that you're looking for! You wrote:

RESEARCH:
· Certain fruits have relatively low water content (bananas, avocados).
· Most fruits have high water content.

(My emphasis added.)

Do you see the distinction between "certain" and "most"? What is interesting to me is *why* they have different water contents - but that is an entirely different question!

Please read over the hypothesis section and let us know if you have any more questions.

Good luck!
Geoff.

[pamsername]

Hi! Thanks Geoff for your help (:
but I am still pretty confused. I read the hypothesis page and it was pretty helpful in letting me know that mine is not right.
but I'm not sure how to fix it.
My variables are:
Independent: The fruits used in the experiment.
Dependent:Amount of water removed from the fruits.

I also know how to remove the water from the fruits. I don't want to go into too detail, but I will take out the water by drying it in an oven. And weigh a before and after, so I have a weight difference.

I still dont really know how to figure out my hypothesis though. Can I please have a MAJOR hint? (:
or you can make one up for me. please? (:

Oh, and with my research. I tried looking for information on why bananas have low water content and I can't find anything. I can't even find any information on why there is water in fruit. You know?

Thanks for your help so far. Have a nice day (:

[geoffbruton]

Hi pamsername,

As you saw, the hypothesis usually is written in the form of an IF ... THEN statement; however, this is not always strictly necessary. Your background research has shown that there are different types of fruit, so you might want to try thinking of your forming your hypothesis in a way that makes a (testable) statement regarding different types of fruit. Does that make sense? For example, you may make a statement like, "Apples contain more water than oranges," or somesuch. This is a testable hypothesis. (I am not suggesting that you use this, but just to give you an idea!)

You have correctly identified the dependent and independent variables , though I would try and think of your dependent variable as the amount of water contained within the fruit(s), rather than the amount your remove. I appreciate that this sounds like the same thing, but it's really depends on your point of view!

As for the question as to why particular fruit have different water contents, I'm afraid I have no idea either! I just think that evolutionary biology is a fascinating subject If you can, try and come up with an application as to why this project is applicable to everyday life. This isn't absolutely necessary, since figuring out the water content of fruit is a neat piece of investigative science all on its own - but if you can think of a reason *why* someone might want to know how much water is in which kinds of fruit, it may help people understand why you chose to study it.

Good luck, and please let us know how you get on.
Geoff.

[rebeccamaman]

Hi pamsername,
This sounds like a mouth watering project. I think Geoff has given you some very useful guidance re the hypothesis. It has to measurable and it sounds like you have come up with a fairly simple way to do the experiment phase of the project. Are you planning to use only a couple of types of fruit or more? Will you be using several examples of each to compensate for any variation in say apple A and apple B?

I do have a thought on why different fruits have different amounts of water in them. I discussed this with some colleages at lunch today. We think the amount of water is related to the availability of water in the place the fruit evolved. Tropical fruits have more water available and less dense flesh. More temperate fruits have denser flesh and less water. Bananas are an exception in the tropical fruits but I am told that banana plants are loaded with water. I can't testify to this as I have always lived in cold climes. I haven't found any really good sources to prove or disprove our theory but it might be interesting to research.

[pamsername]

Hi Geoff!
thanks soo much for your help. I am still a bit iffy, but I think I've gotten it. For my hypothesis, you have made it pretty clear on how I should do it. thankyou!
Okay, so now I thought of one except its pretty similar to my old one & Im not sure if it is testable :S
IN MOST FRUITS, THERE IS MORE WATER THAN DRY MATTER CONTENT.
Is it right? I feel like there is something really wrong about it or I'm still stuck with no good hypothesis.

And thanks for updating my dependent variable. It makes more sense now (:

Thnaks for your help so far. I really need to get started on this soon though since my whole assignment including results from my experiment is due in a couple of days.
Have a nice day (:

And hello Rebecca,
thankyou very much for replying! LOL, mouth watering indeed!
Im planning to use 6 different fruits and of like different types (e.g tropical, berry, citrus, etc). I also want to test fruits in general and not test like, citrus vs melon. Y'know? Since my friend is doing hers like that, I didnt wanna copy (:
Oh and yes, Im going to repeat my experiment with the 6 fruits 3 times each, so I get like accurate-er results.

Hm, you and your friends must be very smart, talking about things like this at lunch! My friends and I just talk about CHEESE & why it is pretty darn awesome! LOL
Thats a pretty good theory! Someone should write a book about it.

Thanks for the help! Have a nice day too!

[pamsername]

Hi, I just came back cos I got a new hypothesis now.
Okay,
"The dry mass of most fruits will weigh less than the mass of water removed, via conventional oven"
"In most fruits, the dry mass will weigh less than the mass of water removed, via conventional oven"
"The dry mass of most fruits weighs less than the mass of water"
"In most fruits, the dry mass weighs less than the mass of water"

Yes, uhm, are they good? Which one should I use? Or if none, tell me that too please (:

[deleted-71588]

"The dry mass of most fruits will weigh less than the mass of water removed, via conventional oven"
"In most fruits, the dry mass will weigh less than the mass of water removed, via conventional oven"

The above bring methodology into your question. Unless you are investigating (comparing) methods, why complicate it and imply a question "Would some other method produce different results?".

"The dry mass of most fruits weighs less than the mass of water"
"In most fruits, the dry mass weighs less than the mass of water"

The above bring a problem of how can you resolve a subjective "most fruits" unless you experiment with a large number of different fruits and varieties. Are dried pineapple and raisons excepted from "most fruits"? Even restricting your choice to "most apples" or "most grapes" would require a large number of different varieties to be tested in order to deal with the subjective "most".

You are beginning to understand the difficulties in coming up with a hypothesis that is easily tested. For science fair projects to be interesting to a wide range of people, you probably want to word your hypothesis with as few scientific terms as you can. Something like "Most of fresh fruits like <replace with a list of your favorite fruits or whatever you intend to test with: apples, oranges, watermelon> is made up of water". Be sure to pick fruits that are in season so you can buy and afford to experiment with.

[pamsername]

Dear Craig,
Hello! So, I shouldnt use the first two since they just complicate things, right? M'kay then.
But for my bottom two, I needa stop using most. Sooo.. is this one good or is it still bad:
Most fresh fruits like strawberries, oranges, rockmelons, apricots, bananas, and apples have a dry mass that weighs less than the mass of water.

Personally, this new one sounds .. um, bad. If it is still not good, can you pleeeeeaaase just fix it for me .. please (: ?
Oh and yeh, I feel like everythings so complicated now.

Thanks Craig, have a nice day.

[MelissaB]

Hi,

One of the things I think Craig is trying to point out is that the word 'most' is problematic. Think about it--what do you consider 'most'? 50%? 60%? 70%? 80%? Something else? Also, unless you randomly choose your fruits from a wider sample of fruits, you can't say that the sample you chose represents 'fruits' in general. To give an example of this, if you said, '70% of fresh fruits have more wet mass than dry mass', and then you only chose different varieties of apples as your sample group, you really couldn't say anything about fruits in general (though if you replaced 'fruits' with 'apples' in your hypothesis it might be closer to being okay).

What I would suggest, if possible, is to try to compare two or more different types of fruit and see how the water percentage changes with fruit species. Do you think fruits commonly used to make juices will have more or less juice than those not usually used for fruit juices, for example?

[pamsername]

AHHHHHH, WHY DOES THIS FEEL SO COMPICATED!

...
Hi Mellisa. hmm, okayokay. how about instead of "most", i use "all fleshy"
so like,
The mass of water in fleshy fruits weighs more than the mass of its flesh.
or
The mass of water in fleshy fruits weighs more than its dry mass.

okayokay, for the two that i have here, my mum wants me to use only fruit flesh (she doesnt want me to include skin, seeds, core, etc) so I'm like 'okay, whatever'. But because Im using an apple, I asked her if I should peel off the skin, and she said 'No, you dont need to cause the skin on an apple is eatable'. And then I was like, 'But doesnt that go against our hypothesis since were supposed to remove the skin?' And she was like 'NO!'
--So, the point of my story is, is my mum right or not? I think shes wrong (lol) cause like the skin of an apple isn't its flesh yknow? And its not like everyone eats the skin. Yknow?
PLEASE HELP ME!
Also, If I was to use dry mass, that means I would have to include every part of the fruits when I dry it. Soo, my mum doesnt like the 'dry mass' cause she doesnt want me to put a whole rockmelon (cantaloupe) into the oven. Because, it will take too long to dry and yeh. So she wants me to have like 100g of flesh from a rockmelon and then weigh that instead of 3 whole rockmelons. So I'll weigh 300g of rockmelon instead of 3 rockmelons. Yknow?

So, can you please help me out here and tell me whether the "mass of its flesh" or "dry mass", which would be a better choice. PLEASE HELP ME !!

Okay, thanks for the help so far. Also,
CAN YOU PLEASE RESPOND ASAP AS MY ASSIGNMENT IS DUE IN TWO DAYS AND IM STILL STUCK IN A RUT ):

[MelissaB]

Hi,

First, the experts here only check the forums every 24-48 hours. We will try to help you, but you'll need to be patient.

I think it's fine if you focus on the 'flesh' rather than the entire thing (your mother is probably right about that--it would be difficult to put an entire melon in the oven). I also think you are right about the apple--if you are peeling the melon and peeling everything else, you should also peel the apple.

'Dry mass' refers to anything dry, not necessarily the whole thing--so I would instead say 'the mass of water in the flesh of fruits weighs more than the dry mass'. That way you make it clear you are only looking at the flesh of fruits rather than at the whole fruit.

Hope this helps!

[geoffbruton]

Hi pamsername,

Glad to see that you're coming along with your project - even though it sounds as though you are still struggling with some of the details of what to study (and how to phrase your hypothesis). This is all part and parcel of working in science - it's something we all go through!

Melissa and Craig gave you some great advice! The refinement of your hypothesis shows that you understand the issues concerned. And I agree that the term "most" is somewhat vague - the more precise your terms, the greater the 'prediction power' of your project - especially since one of the key features of scientific experimentation is that it allows predictions of what you expect to find in the future.

I also like the idea of not studying the entire fruit - which would be fine for small berries but rather challenging when it came to, say, a watermelon! If you examine a given mass of fruit (e.g. 100 g), this will allow for easier calculations and comparisons between the flesh from different varieties of fruit. I also agree with Melissa, re: removing the skin, seeds, etc., and studying the flesh. *However*, please make sure that you say *why* you are doing this, and that there are limitations to consider in performing your experiment this way. There is nothing "wrong" about experimenting with fruits with skins or experimenting with fruit that have had their skin removed. The key issue is that this is a variable - and you want to try and keep as many variables constant as possible when carrying out experiments. Otherwise, if your experiment gave you certain results, you wouldn't necessarily know if the presence or absence of the fruit skin was what produced the result. Does that make sense?

You are making great headway with your science fair project! Keep up the good work and let us know how you're doing.
Best wishes,
Geoff.

P.S.: I really enjoyed hearing about your lunchtime conversations regarding cheese!

[rebeccamaman]

Hi pamsername,
You seem to be refining you hypothesis. I agree that if you peel one fruit you have to peel 'em all. Also Geoff's suggestion about using a standard weight will make your measurements and calculations easier. As for our lunch conversations, they aren't always about such lofty subjects. Keep up the good work. It sounds like a great project and you're well on your way.

[rebeccamaman]

I just remembered I did find a couple of sources that might help you check your data.
http://www.thefruitpages.com/contents.shtml
http://www.ca.uky.edu/enri/pubs/enri129.pdf