Abstract: A UV-treatment unit for reducing the amount of active or living micro-organisms in a liquid food product includes a liquid inlet and a liquid outlet and a set of translucent liquid tubes fluidly connected to the inlet and the outlet and defining a flow channel for the liquid. Each tube has a planar shape providing at least two turns for the flow direction between the inlet and the outlet. The unit includes one or more UV-light sources, which are configured to emit light in a wavelength range between 180-300 nm and arranged on at least one side of the set of liquid tubes. The unit optionally comprises an optical filter placed between the UV-light sources and the set of liquid tubes, the filter configured to prevent wavelengths of more than 300 nm to pass through the filter. Also, a system including the UV-treatment unit is described.