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.