Food Science B

[Gemma W]

Or you can make a completely different type of viscotester - the rules say "can be made" this way, not "must be made". Last year at nationals we used a graduated cylinder and a clay ball to find the absolute viscosity, instead of trying to find a relative viscosity based on other liquids. This works best on more viscous liquids though, and the nationals liquid was not very viscous. It does seem more reliable though in general.

[10manwire]

Okay then, thank you!

[knittingfrenzy18]

Hmm Gemma how does that exactly measure viscosity?

[siciscio]

Well, you measure the time it takes for the ball to drop from a certain point to another point, and then you use a complicated equation to find the actual viscosity, using the density and mass of the ball, the distance it travels, and the time it takes. It does not use relative measurements at all, and can be done with almost no prior preparation. I'm not entirely sure whether or not it's against the rules this year though. Maybe I should ask on the national site. I'm pretty sure that graphs are required in any case, as they are meant to be collected. It worked last year anyway.

Edit: this was actually Gemma, just on a different account by accident.

[Skink]

pretty sure that graphs are required in any case, as they are meant to be collected.

Bingo. I don't have the rules in front of me as reference, but they changed the rules this season with respect to the viscometers and graphs. There are no requirements that I'm aware of offhand that say you have to make a meter the way they want you to, but, either way, you turn in your standard curve. Supposing my understanding is correct, two possibilities emerge:
1. As long as you have a standard curve to give the Supervisor, you're good.
2. If a Supervisor finds a mismatch between the standard curve and the viscometer you brought, I could see them possibly not crediting you for it. Check the Scoring section if there are any caveats.

Edit: this was actually Gemma, just on a different account by accident.

[Gemma W]

You see, I was at scio, and we're at the same school, and I forgot that I was using her laptop and hadn't logged in as me. So yeah.

[PicturePerfect]

How do you measure density with a triple beam balance and a graduated cylinder?

Also, I'm looking at the Food Science ppt. on the soinc.org website, and there's a slide about nutritional labeling. It asks for the total number of calories in one serving (based on the given nutrition facts label). How would I calculate this? (What contributes calories? I know fats, proteins, and carbs contribute calories, but what else? Sodium? Cholesterol?) Thanks!

[cupcakegirl]

How do you measure density with a triple beam balance and a graduated cylinder?

Also, I'm looking at the Food Science ppt. on the soinc.org website, and there's a slide about nutritional labeling. It asks for the total number of calories in one serving (based on the given nutrition facts label). How would I calculate this? (What contributes calories? I know fats, proteins, and carbs contribute calories, but what else? Sodium? Cholesterol?) Thanks!

Well you do know the formula for density right? Mass divided by volume. So measure the mass of a small cube of the cupcake, then either use a ruler or do water displacement to find the volume, then divide the mass of the cupcake by the volume to get the density.

As for calories, I'm pretty sure lipids, carbs, and proteins are the only nutrients that contribute calories to a product. If you are doing the math on a random practice label, keep in mind that they may round the amounts but have the exact calories so it might not come out perfect, but is should be pretty close.
For calculating, all you need to remember is 9-4-4. 9 calories/gram of fat, 4 calories/gram of carbohydrate, 4 calories/gram of protein. If you know that, all that is left is some simple multiplication.

[Skink]

If it helps, remember that you'll break my heart if you forget the formula for density. --> <|3 Look at it sideways. The broken heart is m over V.

[cupcakegirl]

If it helps, remember that you'll break my heart if you forget the formula for density. --> <|3 Look at it sideways. The broken heart is m over V.

That's a really neat way of remembering it! I've never see that before