Perhaps the thing to understand first about foodious ingredients is that they are hierarchical. For example, the parent of bluefin tuna is tuna (all types), and the parent of tuna (all types) is fish.
The reason for this is that some people want to search for any kind of fish, whereas other's search for any kind of tuna, and the rest search for a very specific kind of tuna, e.g.: yellowtail.
This editor serves two primary functions:
The basic ingredient info allows an editor to set/change:
What's key here is that the set of ingredients can all be edited at the same time, which can be very useful to both make the data consistent as well as to [bulk] correct mistakes.
A virtual ingredient is an ingredient that doesn't map to a specific set of nutritional data. A good example of this is ground beef. While this might be an ingredient someone searches for, the ground beef that goes into an actual recipe looks more like ground beef (20% fat) or ground beef (7% fat). In other words, the latter two ingredients have a known set of nutritional data, whereas the first ("ground beef") does not.
A rollup ingredient is always the parent of another set of ingredients, and when searched for, the parent will present a list of it's children. A good example of this is tuna (all types). If you type "tuna" into foodious search, you'll see "tuna (all types)" .. that's the virtual ingredient. It's children (directly underneath it) include mahi-mahi, ahi, yellowtail, and albacore. Those are all real (non-virtual), non-rollup ingredients.
Also editable en masse is ingredient classification data. This section of the tool serves as a sanity check on allergens and diets.
E.g.: if all breads have the "gluten" checkbox checked except one, it's either a mistake or there's a good reason that one bread doesn't contain gluten.
This tool is remarkably useful to help with bulk review of the data, to correct errors, and to ensure consistency in this critical data.
If you want to see the entire ingredient editor as a single image, here's a link to a screen capture of "beef (all types)" in the editor, along with all of it's children.