Their difference is that white pepper is composed without the pericarp. Pericarp contains much of the piperine, so the white corns are more aromatic and less strong, making it less strong than black pepper, but richer in flavor with sweet overtones.

Physical Properties
Color     Dark Brown in color
Appearance                 Free Flowing
Granulation                 As desired. From coarse ground to fine
Aroma                 Characteristic penetrating odor
Flavor                 Pungent biting taste
 
Chemical Properties
Moisture                 Max 12%
Total Ash                 Max 7%
Acid Insoluble ash                 Max 1.2%
Non-Volatile Ether extract                 Min 5.5%
Crude fiber                 Max 18%
Volatile Oil                 Min 2%