Probably not, fuel and the tankers that carry it are legitimate war cargoes one can attack and destroy.
Grain ships are a different matter.
This ship and the company which owns her are currently under criminal indictment by the US. As a reality the Russian government is the actual owner. She is made to carry jet fuel for military aircraft. She's already been listed as an outlaw, and subject to being arrested and / or seized for carrying war cargoes to Syria.