The relationships between processing parameters such as grinding, defatting, extraction, and drying and structure-functional properties such as thermal characteristics, absorption, and emulsifying properties of lupin protein preparations obtained from low alkaloid seeds of Lupinus luteus var. Topaz were investigated with the use of different methods. Samples included grits undefatted and hexane-defatted flours and isolates obtained by alkaline and Na Cl-solution extraction. The isolates were freeze- or spray-dried. Denaturation characteristics was studied with the use of differential scanning calorimetry, and solubility, water and fat adsorption, activity and stability of emulsions with the use of a conventional functional analysis. Results showed modifying influence of the preparation methods on structure and properties of protein reflected in thermodynamic characteristics, solubility, water and fat absorption as well as emulsifying properties. Alterations of lupin protein fractions were visible on DSC thermograms. Alkaline-extracted and freeze-dried isolates showed altered DSC thermograms and worse functionality than flours, while spray-dried protein isolate was completely denaturated but presented the best functional properties.