Food Nutrient Testing - Page 2

Spracklcat · 05-22-2007, 08:38 AM

Can you give us an idea of your experimental design? Are you going to grind the foods, suspend them in water, and then use test kits? Something else? Is the centrifuge just to separate the suspended foods from the liquid?

One thing to consider too is that the food item itself may have a certain composition, but after a day in aquarium water it will have very different composition (and different nutrients (because of the bacteria and microalgae in the water column working on it...

**ShaunW** · 05-22-2007, 12:20 PM

Eric, don't you just want to remove the phosphate used to grow the cells? Centrifugation followed by the removal of the supernatant will get rid of most inorganic phosphate. You could always wash the cells before resuspension.

This is what I would do:
1. Centrifuge cells at lowest speed to pellet cells.
2. Pour off supernatant, keeping the pellet undisturbed.
3. Resuspend the pellet in pure/freshly made salt water.
4. Mix the cells into suspension.

If your concerned about left over phosphate/wash the cells.
5. Centrifuge cells again.
6. Pour off supernatant, keeping the pellet undisturbed.
7. Resuspend the pellet in pure/freshly made salt water.
8. Mix the cells into suspension.

What centrifuge did you end up getting?

Paul B · 05-22-2007, 07:32 PM

Oh nutrient levels, I thought you were testing for nutrition levels.
Never mind

**ShaunW** · 05-22-2007, 08:15 PM

Quote:

Originally Posted by Paul B


	Oh nutrient levels, I thought you were testing for nutrition levels. Never mind

I think you were correct, and I changed the subject somewhat from the original post,

.

This is a tough project, really comes down to accurate measuring and the relative breakdown/decay time of each food tested.

GreshamH · 05-23-2007, 04:42 PM

There's a lot of hurdles as well. With at least phyto, every species has a whole different protocol when using a centrifuge. Browns react far different then greens, etc. I can give you some guidence offline for the phyto end to a certain degree. Not to mention other factors such as shelf life, COC handling, etc.

spskibitzer · 07-23-2007, 04:28 PM

great idea...I was just getting ready to try and find info on this exact thing...can you test "Ocean Nutrition Formula Two" thanks in advance can't wait to view the findings

05-22-2007, 08:38 AM	#11
Spracklcat Member Join Date: Sep 2006 Posts: 101 Reefer Ratings: (1) Friends: (0)	Can you give us an idea of your experimental design? Are you going to grind the foods, suspend them in water, and then use test kits? Something else? Is the centrifuge just to separate the suspended foods from the liquid? One thing to consider too is that the food item itself may have a certain composition, but after a day in aquarium water it will have very different composition (and different nutrients (because of the bacteria and microalgae in the water column working on it... __________________ "...this brings out so many wonderful emotions... joy... excitement... looking." --M. Simpson

05-22-2007, 12:20 PM	#12
ShaunW Moderator Join Date: Aug 2003 Location: Brooklyn, NY Posts: 4,662 Reefer Ratings: (37) Friends: (0)	Eric, don't you just want to remove the phosphate used to grow the cells? Centrifugation followed by the removal of the supernatant will get rid of most inorganic phosphate. You could always wash the cells before resuspension. This is what I would do: 1. Centrifuge cells at lowest speed to pellet cells. 2. Pour off supernatant, keeping the pellet undisturbed. 3. Resuspend the pellet in pure/freshly made salt water. 4. Mix the cells into suspension. If your concerned about left over phosphate/wash the cells. 5. Centrifuge cells again. 6. Pour off supernatant, keeping the pellet undisturbed. 7. Resuspend the pellet in pure/freshly made salt water. 8. Mix the cells into suspension. What centrifuge did you end up getting? __________________ *"I believe there are more instances of the abridgement of the freedom of the people by gradual and silent encroachments of those in power than by violent and sudden usurpations."* - James Madison, to the Virginia ratifying Convention, June 16, 1788. "I sincerely believe.....that banking establishments are more dangerous than standing armies, and that the principle of spending money to be paid by posterity under the name of funding is but swindling futurity on a large scale." -Thomas Jefferson

05-23-2007, 04:42 PM	#15
GreshamH Senior Member Join Date: Dec 2006 Location: SF Bay Area, CA Posts: 149 Reefer Ratings: (0) Friends: (0)	There's a lot of hurdles as well. With at least phyto, every species has a whole different protocol when using a centrifuge. Browns react far different then greens, etc. I can give you some guidence offline for the phyto end to a certain degree. Not to mention other factors such as shelf life, COC handling, etc. __________________ ________... Gresham _________________________________... Feeding your reef...one polyp at a time

07-23-2007, 04:28 PM	#16
spskibitzer Faiva Monger Join Date: Jul 2007 Location: Lindenhurst South Shore LI Posts: 84 Reefer Ratings: (4) Friends: (1)	great idea...I was just getting ready to try and find info on this exact thing...can you test "Ocean Nutrition Formula Two" thanks in advance can't wait to view the findings __________________ -Sullen wings of fortune beat like rain. Youre back in terrapin for good or ill again, for good or ill again-

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05-22-2007, 07:32 PM	#13
Paul B Three decade club Join Date: Feb 2007 Location: New Hyde Park Posts: 737 Reefer Ratings: (3) Friends: (2)	Oh nutrient levels, I thought you were testing for nutrition levels. Never mind