Iron in raisins

How come raisins have more iron than grapes?
Same goes for other dried fruits - whenever I read a list of foods high in iron, they always mention raisins and other dried fruit, but not the fresh stuff.

Great question, zyada. Iron is, after all, necessary for a “magnetic” personality.

Actually, it’s about size. A 1/2 cup of grapes delivers .14 milligrams of iron. Conversly, a 1/2 cup of raisins contains 1.5 mg’s of iron. Thing is, 1/2 of raisins is about 8 or 9 times the amount of grapes.

Size does matter.

Could itnot be that when the grapes were being dried they some how attracted airborne iron?

If you can’t dazzle them with brilliance, baffle them with bullshit.

I think it only applies to sun-dried raisins. Here’s why : <snicker>
The iron is a by-product of solar radiation. As the grapes slowly dessicate under the blaze of Yon Sol, and become “Sun Maid”, the extra iron particulates bombard the grape/raisin zygotes, PENETRATING the grapes and raising the …uh…raisins’ iron levels.

Quid Pro Quo, Carpathia Diem ( Seize the Vampyre )


I don’t get the joke. Is “Carpathia” the name of a vampire? If so, it explains something in a book series I’ve been reading…

Of course, it then makes your quote read (loosely)

This for that, vampire day…

in which case I still don’t get the joke.

I wanted to check sly’s answer, so I went to a site that gives the amount of various nutrients for different foods. I got the number for 100 grams of raisins & grapes, then calculated a raisin portion that would give me the same calories as the grapes. Result:
About the same amount of fiber
A little less potassium
Nearly twice a much iron.
If you want the numbers I got, tell me…but it’s too late tonight for that.

And torq, Carpathia is IIRC the area where Vlad hung out. Appropriate for this thread, since iron is necessary for red blood cell production.

Maybe I should become a vampire…

I’ll go with Sly. You can’t go by grams. Much of the grams in fresh grapes is water. Drying, of course, removes the water grams from each grape, but presumably leaves the iron intact – a fixed number of grams of iron per grape, fresh or dried. But you will have more individual grapes either per volume measure, e.g., per cup, or per weight measure, e.g., per gram, and thus more iron per cup or per gram.

Ray (It’s cut and dried.)

It ain’t no good to go ironin’ raisins. They stay wrinkly no matter how hard you press.

Nanobyte, let’s try this again: I said

So here are my numbers:

100 grams raisins:
300 Calories
4 gr. fiber
751 mg Potassium
2 mg Iron

100 grams grapes:
67 calories
1 gr fiber
191 mg Potassium
0.29 mg iron

Now I calculate a portion of raisins to match calorically the 100 grams of grapes:

300 / 4.48 = 66.96 calories so divide everything by 4.48:

22.32 gram serving
66.96 calories
.89 gr fiber
167.63 mg Potassium
.44 mg iron

So, unless my math is wrong or rounding error accounts for it, there’s still nearly half again a much iron in the raisins as there was in the grapes, when you match portions based on calories.

I don’t know if this advances the discussion much but I don’t think I’d put too much faith in the accuracy of the product labels. Anything within a factor of 2 is probably as good as you can expect.


“non sunt multiplicanda entia praeter necessitatem”
– William of Ockham