optimization of low-fat butter formulation according to its organoleptic properties using response surface methodology (rsm)

low-fat butter is water in oil emulsion comprising a continuous fat phase including butter, emulsifiers and colorants and also a dispersed aqueous phase including water, stabilizers and proteins. in this research, by using protein components especially full-fat soy flour, a product were produced which has extreme similarity to ordinary butter and also has good organoleptic properties. water : butter ratio, soy flour : sodium caseinate ratio and emulsifier content were the designed factors and their effects on sensory properties of low-fat butter such as softness, spreadability, crumbling, hardness, adhesiveness, cohesiveness, melting rate, mouth coating, gumminess, butter flavor, soy flavor and finally overall acceptance were evaluated. the central composite design (ccd) and response surface methodology (rsm) were employed as experimental design and statistical analysis. based on final results, the optimum formulation for low-fat butter were: water : butter ratio as 1.03 (50% water and 48.5% butter), soy flour : sodium caseinate as 1.57 (5% soy flour and 3.2% sodium caseinate) and 0.66% emulsifier. apart from good nutritional effects of final product due to high protein content and lower fat content, that was spreadable at low temperatures and also has plastic characteristics of butter at ambient condition.