Influence of different levels of aqueous phase, proteins and emulsifiers on rheological properties of low-fat butter

In this research, the production of low fat butter, as a novel product, based on full-fat soy flour and sodium caseinate was studied. Water: butter ratio, soy flour: sodium caseinate ratio and emulsifier content were the designed factors and their effects on rheological properties of low-fat butter such as hardness, spreadability, adhesiveness, elasticity and consistency were evaluated. The Central Composite Design (CCD) and Response Surface Methodology (RSM) were employed as experimental design and statistical analysis. By increasing water to butter ratio, as a principal factor affecting on product characteristics, hardness, adhesiveness, elasticity, consistency and spreadability were reduced. The final product was w/o emulsion which was low-calorie, had functional and nutritional effects due to protein components and also its properties could be compared with ordinary butter. 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.