pulpa

the soft part of an animal's body; flesh; the fleshy part, pulp of fruit; the pith of wood; the softest meat of beef or pork; pulp (for producing paper)

Inherited from Latin pŭlpa, perhaps via an unattested Old Spanish *pupa, with /l/ restored by Latin influence or contact with forms like Portuguese polpa. Compare the evolution of Spanish dulce < duce < dŭlcem.