Preheat oven to 350 degrees F
In a small bowl, combine the ketchup, brown sugar, 1 tablespoon lemon juice and mustard powder.
In a separate large bowl, combine the ground beef, bread, onion, egg, bouillon, and remaining lemon juice.
Add 1/3 of the ketchup mixture from the small bowl.
Mix well and place in a 5x9 inch loaf pan.
Bake at 350 degrees F for 1 hour.
Drain any excess fat, coat with remaining ketchup mixture.
Bake for 10 more minutes.