Abstract Producing passion fruit juice involves separating the juice sacs from seeds, a tedious operation which can affect the juice quality. To improve this operation, the morphology and biochemical composition of arils were studied. The aril has two major membranes, one external, which retains almost two‐thirds of the juice, and one internal that retains the other third. The two membranes are composed of a single‐cell layer which stains for pectin. To solubilize the middle lamella and free the juice, only 18 nkat of pectinlyase activity per litre was needed. Copyright © 2003 Whurr Publishers Ltd