"enriched in" vs "enriched with"

Question

I have a mixture of different things and now I artificially make it so that there is more of one component or ingredient in my product. Do I then say, "A is enriched in B" or "A is enriched with B"? Is there a difference in the meaning? Which one is more appropriate?

Example:

• enriched with vitamins
• enriched in a certain isotope
• a selection is made to be enriched in a certain type of contribution

("enriched with" yields twice as many Google results as "enriched in" but I think I would always tend to use the latter.)

Answer 1

ODO includes the following different subsenses for enrich:

enrich [verb]

...

1.1 Add to the nutritive value of (food) by adding vitamins or nutrients.

porridge oats enriched with extra oat bran

[M-W has The drink is enriched with vitamin C.]

1.2 usually as adjective enriched Increase the proportion of a particular isotope in (an element), especially that of the fissile isotope U-235 in uranium, so as to make it more powerful or explosive.

enriched uranium

[M-W has the more general enrich ... to add or increase the proportion of a desirable ingredient] ...

Uranium for the first atomic bomb and for nuclear reactors was enriched in the 235 isotope, as compared to the more abundant 238 isotope, by gaseous diffusion.

So 'enriched with X' means X has been added, often where there was none originally;

'enriched in X' means the proportion of X [already] in the sample etc has been increased.