The lobster sauce herring jar contains sugar for seven people. Canned lobster sauce contains sugar. Because the main raw material of canned shad is shad (also known as mud shad and swordfish). This fish has a flat body, a round abdomen and a bluish-gray back. This kind of freshwater fish is tender, sweet and prickly, suitable for canning. It is generally known that fish contains protein maltose, both of which are sweet.