TVP can be made from soy flour or concentrate, containing 50% and 70% soy protein respectively, and is relatively flavorless. Both require rehydration before use, sometimes with flavoring added in the same step. TVP is extruded, causing a change in the structure of the soy protein which results in a fibrous spongy matrix that is similar in texture to meat. In its dehydrated form TVP has a shelf life of longer than a year, but will spoil within several days after being hydrated. In its flaked form TVP can be used similar to ground meat.