The Effect of Minor Components of Wheat Germ Oil on Thermal Behavior, Crystallization Characteristics and Oxidative Stability of Butter Oil

Abstract

Minor lipid components (MLCs) can be added to fats to improve some of their chemical and physical properties and reduce the health risks associated with them. The effect of adding MLCs extracted from wheat germ oil (WGO) on oxidative stability (OS), thermal behavior, slip melting point (SMP), solid fat content, and crystallization properties of butter oil (BO) was studied. The MLCs were added to butter oil (BO) at a rate of 0.25, 0.5, 0.75, 1.0, and 1.5%. The main phytosterols in the MLCs of WGO were β-sitosterol and campesterol, with concentrations of 806.25±24.76 and 374.6±117.61 mg/100 g, respectively, whereas the main tocopherols were α- and γ-tocopherols. The addition of MLCs could significantly affect the melting and crystallization properties of BO. The SMP of BO increased as the concentration of MLCs increased; it increased from 33.3°C in pure BO to 35.4 °C in BO containing 1.5% MLCs. A pure BO had smaller and more numerous spherical crystals than any other BO sample containing MLCs; however, BO containing 1.5% MLCs showed a notably larger crystal aggregation. The addition of MLCs to BO could significantly affect its thermal behavior and OS. The ΔH decreased from 46.19±1.11 J/g in pure BO to 20.15±1.23 and 16.21±1.02 J/g in BO containing 0.25 and 0.50% MLCs, respectively. The OS increased in proportion to the MLC content; this increase was more noticeable in BO containing 0.25 and 0.5% MLCs, which were respectively two and three times greater than pure BO.