In high pressure homogenisation, the non-homogenised fruit or vegetable based product enters the valve of the homogeniser at relatively low velocity. The pressure is then generated by a pump and the restriction to flow caused by the passage of the product through a very small gap (see Figure 1). The product flows between the valve and the seat at high velocity. As the velocity increases, the pressure decreases producing an instantaneous pressure drop. The fluid is finally discharged as the homogenised product (7). Phenomena of cavitation, shear and turbulence occur during the homogenisation process (8), leading to the disintegration of cell structures and wall material and the incorporation of oil into fruit- and vegetable-based products.