You can freeze them. This prevents any oxidation.
A big hit was strawberries with black pepper.
When pepper is ground, it oxidizes and loses its oils. It has no pungency. If you buy ground pepper always look for the sell-by date.
When grilling, I like really good sirloin steak. I use three peppers: green, white, and black in a coarse grind. I press the pepper into the steak and just grill.