Some changes have scaled back allowable serving sizes and offerings in the state. Suppliers of tetrahydrocannabinol, or THC, are seeing a surge in the sales of hemp-derived edibles and beverages following Minnesota's change in law. Those 21 years or older may now buy products that contain up to 5 milligrams of THC per serving and 50 milligrams per package. Prior to the new law going into effect on July 1, hemp and cannabidiol, also known…