Apparently the whole cumin seed contains oil which the ground version doesn't. However when I crunch one down I never notice any oil coming out. Where is it? I would like it to mix with my cooking oil.
(if I read the question properly) " I would like it to mix with my cooking oil."
If you want cumin flavored oil, you can simply steep the cumin seed in a neutral flavored oil.
You will have to experiment for quantities and steep times.
I'd crush some seeds, put them in a pan and add some oil (whatever quantity, start small) and slightly heat the oil and turn off the heat; let steep for a while until cool. Use a fine mesh sieve to remove the cumin seeds from the oil.
Where is it?
According to Wikipedia, "Cumin seeds have eight ridges with oil canals." I'd suspect these canals to be the "home" of the essential oils (= volatile, fragrance/flavor giving oils).
Apparently the whole cumin seed contains oil which the ground version doesn't.
Total oil content of cumin seeds is ≈ 15 %, but the volatile essential oils are only 1 - 5 %. See e.g. Bettaieb et al.: Essential oils and fatty acids composition of Tunisian and Indian cumin (Cuminum cyminum L.) seeds: a comparative study, J Sci Food Agric, 2011, 91: 2100–2107.
keep in mind:
- comparison 1: if you squeeze a sunflower seed e.g. on a piece of paper, you may see the oil as spot. Sunflower seeds have oil contents around 50 %.
- comparison 2: a mixture of flour and oil with 15 % oil content is sometimes used as "indoor sand" for kids to play, there isn't any oil dripping off this, neither.
- lipids (including oils) are important parts e.g. of cell walls etc., so even if the pure oil is a liquid substance, it may be bound in the strucure of the seed (and still in the or seed powder) in a way that you don't recognize it as liquid.
- as long as the powder has the characteristic smell of cumin, (some of) the essential oil is still there.
I would like it to mix with my cooking oil.
Yes, you can extract oil that way as it is miscible with your cooking oil.