A process for optimizing the extraction at room temperature of juice or puree from food pulps of fruit and vegetables having a predetermined consistency, said process comprising the steps of: - softening said food pulps in a softening section of a machine, said softening section having at least a first stator having protrusions on the inner surface and a first rotor arranged to rotate at a first speed; - driving by a first rotor drive means the first rotor for applying a plurality of pulses in quick succession to the food pulps against said first stator in such a way to obtain a softened product in said softening section, said first rotor drive means comprising a first motor operating a first shaft on which the first rotor is mounted; - feeding said softened product to an extraction section, said extraction section provided with at least a second stator and a second rotor arranged to rotate at a second speed; - extracting in said extraction section a juice or puree from said softened product, driving by a second rotor drive means said second rotor, the second rotor drive means comprising a second shaft on which the second rotor is mounted and a second motor operating the second shaft, the first and the second shaft (8,18) rotating independently from each other; - driving said second rotor by a second rotor drive means, said second rotor drive means comprising a second shaft on which the second rotor is mounted; - operating said first shaft by the first motor for causing said first rotor to rotate at said first speed, - operating the second shaft by the second motor for causing said second rotor to rotate at said second speed - operating by a speed adjusting means (20,30), which is operatively connected to said first and to said second rotor drive means, said first and said second rotor driving means according to a predetermined ratio between said first and said second speed responsive to an input parameter relative to the consistency of the food pulps, said speed adjusting means (20,30) comprising a means for receiving an input parameter through a processor; - setting in said processor an input parameter related to said consistency; - actuating by said rotor driving means said rotors according to said predetermined ratio between said first and said second speed. - softening said food pulps in a softening section of a machine, said softening section having at least a first stator having protrusions on the inner surface and a first rotor arranged to rotate at a first speed; - driving by a first rotor drive means the first rotor for applying a plurality of pulses in quick succession to the food pulps against said first stator in such a way to obtain a softened product in said softening section, said first rotor drive means comprising a first motor operating a first shaft on which the first rotor is mounted; - feeding said softened product to an extraction section, said extraction section provided with at least a second stator and a second rotor arranged to rotate at a second speed; - extracting in said extraction section a juice or puree from said softened product, driving by a second rotor drive means said second rotor, the second rotor drive means comprising a second shaft on which the second rotor is mounted and a second motor operating the second shaft, the first and the second shaft (8,18) rotating independently from each other; - driving said second rotor by a second rotor drive means, said second rotor drive means comprising a second shaft on which the second rotor is mounted; - operating said first shaft by the first motor for causing said first rotor to rotate at said first speed, - operating the second shaft by the second motor for causing said second rotor to rotate at said second speed - operating by a speed adjusting means (20,30), which is operatively connected to said first and to said second rotor drive means, said first and said second rotor driving means according to a predetermined ratio between said first and said second speed responsive to an input parameter relative to the consistency of the food pulps, said speed adjusting means (20,30) comprising a means for receiving an input parameter through a processor; - setting in said processor an input parameter related to said consistency; - actuating by said rotor driving means said rotors according to said predetermined ratio between said first and said second speed.