A dispensing assembly (2) for a machine for the preparation of liquid food products comprises a preparation chamber (7, 8) and a hydraulic circuit (20), which is configured for supplying water and/or steam to the preparation chamber (7, 8). The preparation chamber (7, 8) is configured for receiving at least one dose (9) of a precursor of a liquid food product and for dispensing the liquid food product following upon passage of water and/or steam through the preparation chamber (7, 8). The preparation chamber comprises a first chamber part (7), preferably configured for introducing water and/or steam, and a second chamber part (8), preferably configured for dispensing the liquid food product. At least one chamber part (8) is displaceable with respect to the other chamber part (7) between a spaced-apart position, to enable loading of the aforesaid dose (9) into the preparation chamber, and a close position, to enable introduction of water and/or steam into the preparation chamber and dispensing the liquid food product therefrom. The dispensing assembly (2) further comprises a pneumatic circuit (30) configured for supplying compressed air to the preparation chamber, in particular when the first chamber part (7) and the second chamber part (8) are in the close position.