Welcome to SP!
I'm sorry that a lot of your items are not in there, but the majority of the food items come from the USDA database and the rest come from us manually adding them using the information on certain manufacturer's websites. If you don't find something in the tracker, you can always use the link to manually enter a food item so you can have that in your own tracker. Also, you can try using the button to import foods from other members - you may find some items there to be useful.
Sorry I don't have a better answer for you!