ABSTRACT:This paper reports on the impact of shear on crystallisation upon cooling of palm oil.Samples were cooled down under shear from 70 °C to 10 °C, then kept at this temperature, while performing rheological measurements using a controlled shear rate rheometer and rheo-optical observations using optical microscopy and small-angle light scattering. Shear rates between 1 and 300 s -1 were investigated. Two crystallisation steps were observed, characterized by associated viscosity increases. The effect of shear on these two crystallisation processes was investigated. Shear was shown to influence almost all the steps of the structuring process of the crystallizing palm oil. The spherulite size and growth rate during the first crystallisation are affected by shear. The onset time of the secondary crystallisation process strongly depends on the extent of shear. The steady state structures after the first and the secondary crystallisation processes constituted of a suspension of aggregates of spherulites are controlled by the applied shear rate. PRACTICAL APPLICATION:The texture of crystallised vegetal fats and subsequent end product properties depend on the structure developed during the crystallisation process. This structuring process is strongly influenced by the thermo-mechanical history submitted to the product (cooling rate, degree of undercooling, annealing time, application of flow). This paper shows how the extent of shear affects the different steps of the crystallisation and aggregation processes in the case of palm oil after the first crystallisation.