1 Answer

The pimiento was originally hand cut into small pieces and hand stuffed in olives to complement the strong flavor of the olive; however, this method was very time intensive. In the industrial era, the cut pimiento was shot via hydraulic pump through the olive, getting rid of the pit in the process.
For ease of production,[1] pimiento is sometimes puréed and formed with the help of a natural gum (such as sodium alginate or guar gum) into strips. This allows the olive stuffing to be completed by a machine, lowering the cost of production. However, guar (an annual legume mostly produced in India) may inadvertently make the olives less accessible to consumers with peanut allergies, as those individuals may have a cross-reaction to the guar. This leaves sodium alginate as a more universal choice. http://en.wikipedia.org/wiki/Pimento