Purification Of Sunflower Waxes And Application In Organogels

The crude sunflower oil wax sludge was purified by N-hexane, ethylacetate, actone and isopropanol in this study. The purity and recovery rate was to investigate by four solvents at different extraction time, temperature and solid-liquid ratio, and the optimal solvent was selected. The purity, composition and thermal behavior of the purified sunflower waxes were studied. The physical and chemical properties of the organogels made by sesame oil and oil structurants such as sunflower wax, rice bran wax, beeswax and carnauba wax were investigated.The distributed multiple extraction method was selected to reduce the consumption of solvent and to improve the purity and recovery rate of the sunflower waxes. The resultes showed that the optimal extraction conditions were as followes:extraction solvent of isopropanol, crude sunflower oil wax to isopropanol ratio of 1:6(m/v), extraction temperature of 50℃, extraction time of 50 min, and extraction times of 4, under which the purity of the refined waxes was over 95% and the recovery rate was higher than 90%.The composition of the purified waxes determined by high temperature gas chromatography were C42~C58 ester, in which the C44, C46 and C48 esters were the major components, and the contents were 30.60%, 25.37% and 13.75%, respectively. The infrared spectral data indicated that the purity of refined waxes was high. There was a certain relationship between purity and the thermodynamic parameters of the sunflower waxes. The lower the value of ΔT1/2((To-Ts)/2), the higher the purity; the higher the value of Tp and ΔH,the higher the purity. The melting point, ΔT1/2 and enthalpy of purified waxes were 74.45℃,2.93℃ and 224.0J/g, respectively.The physical and chemical properties of organogels were effected by the mechanical stirring. The number of three dimensional network structure increased with gel factor.increased. The organogels were pseudoplastic fluid of the non-newtonion fluid. The properties of the organogels were effected by temperature, and the Brownian motion of themolecules increased under high temperature, the resistance and the viscosity decreased under the same conditions. The viscosity of the organogels were increased with increased amount of the gel factor. The disordered micelles were formed with the Brownian motion of the molecules becomes fast enough to get rid of the force from the junction between the micelle when the temperature was higher than 40℃.The solid fat content(SFC) of the organogels as a result of descending were: sunflower wax-organogels>rice bran wax-organogels>carnauba wax-organogels>beeswax-organogels,and the hardness of the organogels were: sunflower wax-organogels>rice bran wax-organogels>beeswax-organogels>carnauba wax-organogels.