Influence of unregulated storage conditions on physico-chemical, organoleptic and NIR spectral characteristics of yellow cheese

¹ Faculty of Engineering and Technology, Faculty of Technics and Technologies, Trakia University, 8602, Yambol, Bulgaria
² Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

^* Corresponding author: zlatin.zlatev@trakia-uni.bg

Abstract

In the present work, software and hardware tools are proposed for determining the change in the main characteristics of Bulgarian yellow cheese during storage in conditions not regulated by the manufacturers. NIR images in the 800-1100 nm range of yellow cheese samples from 3 manufacturers were obtained using a GT-903 video camera with the IR-filter removed from the camera lens. Several physicochemical characteristics of the product were determined - active acidity, electrical conductivity and completely dissolved solids. Data from organoleptic evaluation of the product are presented. Using ABC- XYZ analysis, informative wavelengths are selected from the spectral features. Spectral indices calculated as ratios of the reflectance coefficients of selected wavelengths were defined and used to predict the storage characteristics of yellow cheese. It has been found that the shelf life of yellow cheese can be predicted with an accuracy of up to 95%, and the active acidity with an accuracy of up to 88%, depending on the manufacturer. The obtained results can be used for analyzes of yellow cheese during its storage and applied in automatic measurement and control systems, as well as in advisory systems for evaluating the quality of yellow cheese in the different stages of its production, transport and storage.