A flash boiling apparatus for a liquid food product that includes particles, the apparatus including a vacuum vessel provided with a product inlet and a product outlet for liquid food product, a pressure relief valve arranged upstream the product inlet for providing a pressure drop that results in flash boiling of the liquid food product, and an inlet section arranged between the pressure relief valve and the product inlet, for conveying the liquid food product from the pressure relief valve to the product inlet. The inlet section includes a through-flow area that increases in a direction from the pressure relief valve to the product inlet, such that a flow velocity of the liquid food product decreases when it passes the inlet section.