Hi, I bought an Atkins carb guide and keep it in my bag for any emergency occasions when I may have no option but to eat so I can limit the damage as much as possible.
It says in the book that 1 teaspoon of white pepper has 1.4g of carbs (0.9g net carbs) and 1 teaspoon of black pepper has 1.3g of carbs (0.8g net carbs) - I believe it is the net carbs that are the important figures to count.
I can't imagine that it would make too much difference going on those figures would you?