There has been an increasing demand for reduced-fat versions of food that contain cheese powder as a flavouring ingredient. Therefore, we must reveal their positive and negative aspects as a result of fat reduction and accordingly redesign the production of cheese powders with reduced-fat formulations. We aim to determine the impacts of fat reduction and microparticulated protein (MP) addition (as a fat replacer) on the characteristics of cheese powder. Three different white cheese powders, namely, full-fat cheese powder (FFCP), reduced-fat cheese powder (RFCP), and reduced-fat cheese powder with microparticulated protein (MPCP) were produced by spray drying, and their densities, reconstitution properties (solubility, dispersibility, and wettability), particle morphologies, colour differences, free fat contents, lipid oxidation degrees, and sensory properties were investigated during a 12-month storage period at 20 degrees C. A total fat reduction by up to 60% could be achieved in the cheese powders produced from reduced-fat cheese. Throughout the storage period, RFCP had the lowest free fat content, with the increase in its wettability, dispersibility, and flowability and reduction in its caking degree; however, FFCP, with the highest free fat content, had converse results for these properties. The solubility index of powders produced from reduced-fat cheese was lower than the full-fat counterpart. From the beginning of the storage period, the lowest lipid oxidation degree was observed in RFCP, although the addition of MP triggered lipid oxidation. Although RFCP had few and large particles that were inwardly buckled in shape, MPCP, similar to FFCP, had altered morphology and a small particle size with less wrinkle formation. The intensities of cheese flavour and overall impression slightly decreased for the cheese powders made from reduced-fat cheese. The use of MP increased the flavour and overall impression scores of potato samples and enhanced the solubility of the reduced-fat cheese powder on the surfaces. Consequently, fat reduction in cheese powder formulations offers an approach to improve their physical properties and oxidative stability, and the addition of MP may be considered as a way to promote fat reduction and create morphological characteristics similar to those of full-fat powder. The addition of MP might be an interesting tool to enhance consumer acceptance of food products formulated/flavoured with reduced-fat cheese powder. (c) 2021 Published by Elsevier B.V.