I would like to know how long it takes for the human body to absorb / digest a 10mg zinc capsule?
Note: It is recommended to take zinc an empty stomach to gain the maximum effect. Regarding to that I think it's also a disadvantage to eat something right after taking zinc?
Zinc supplements are usually used to treat zinc deficiency or other chronic conditions, so it is not that important in what time they are absorbed but what percent of them is absorbed.
They are certain nutrients, such as calcium (for example, in milk) that can bind to zinc and partially prevent its absorption. This is why it is usually recommended to take zinc on an empty stomach (Mayo Clinic):
Zinc supplements are most effective if they are taken at least 1 hour before or 2 hours after meals. However, if zinc supplements cause stomach upset, they may be taken with a meal.
Usually there should be no significant difference between taking a pill with food, 2 minutes before or 2 minutes after the food, because in all cases the pill and the food will mix in the stomach. This is because every pill, even if you take it with water, will probably stay in the stomach for at least few minutes before it will be emptied into the small intestine.