What Is In Spam With Bacon?

Wired:

Pork With Ham
That’s what the label says: “pork with ham.” Is there a difference? According to the USDA, ham is the hind leg of a pig that’s been preserved, colored, and flavored through a process known as curing, while pork is just “meat from hogs.” According to Hormel, the pork in Spam is usually shoulder meat. What’s certain is that the pig flesh is vacuum-sealed in the can while still raw and then cooked for three hours. Hormel says this gives Spam an indefinite shelf life, making it the go-to food for Depression-era Okies and would-be subterranean nuclear holocaust survivors. (The company concedes that the flavor may change after three or more years on the shelf.)
Modified Potato Starch
Three hours of cooking in the can would tend to squeeze some of the moisture out of Spam. Modified potato starch to the rescue! The starch traps water molecules, binding that juicy goodness in the loaf. Hormel credits it with maintaining “the delightful texture characteristic to SPAM©.”

There's more there, including the definition of the bacon.