The study was aimed at investigating the hygroscopicity of food concentrates. The sorption phenomenon measurement was made with a static method on the basis of steam adsorption isotherms analysis and with a dynamic method by determination of steam adsorption kinetics and process rate. Sorption isotherms were determined at water activity range of a_w=0.07-0.98. The monomolecular layer capacity V_m and corresponding water activity and the adsorption specific surface were determined after rearrangement of the sorption isotherms BET. Steam adsorption isotherms of the researched croutons are corresponding to the type II in the Brunauer’s classification. While for the researched powders constituting the pea soup concentrate, sorption isotherms were the indirect type between II and III according to the Brunauer’s classification. Higher monolayer capacity and the adsorption specific surface characterised croutons and powders of the producer A, which achieved results indicating a better flexibility to the re-hydration process.