Blood products are known to be deteriorating during storage. Recent efforts to determine the quality of blood products with a non-invasive technique during storage have gained momentum. Previous studies have shown that the degree of hemolysis, quality indicator for erythrocyte suspensions, correlates with the color parameters measured by noninvasive color measurement technique. In this study; we tried to model the diffuse reflectance values of the blood products, measured from the outside of the bag, and the physiological changes inside the blood with the mixed model. Experiments were performed on 24 unfiltered erythrocyte suspensions and 28 leukocyte filtered erythrocyte suspensions for 70 days of storage period. This paper contains the findings and the results obtained from the project realized in the Northern Marmara Region Blood Center with the permission of the General Directorate of Blood Services of the Turkish Red Crescent.