A process for optimizing the efficiency of extraction at room temperature of juice or puree from pulps of fruit and vegetables, responsive to their consistency. The pulps are first cut and softened in a first section of the machine, where a rotor applies pulses to the pulps in quick succession against a stator having protrusions on the inner surface. The softened product then passes through an extraction section, where the separation is carried out of a main product, which is conveyed in an outlet duct, from the waste solid parts, which are discharged through an outlet. The rotors are mounted on different shafts operated by motors. Both motors are operatively connected to a device that controls the speeds manually, or automatically, responsive to predetermined input parameters, according to the consistency of the product.