BACKGROUND: Solid fat was produced from mustard oil and palm stearin through lipase-catalyzed reaction, in which linoleic acid was intentionally incorporated. For optimizing the reaction condition of melting point and ω6/ω3 fatty acids, response surface methodology (RSM) was employed with three reaction variables such as substrate mole ratio of mustard oil (MO) to palm stearin (PS) (X1), reaction temperature (X2) and reaction time (X3).
RESULTS: The predictive model for melting point of solid fat was adequate and reproducible due to no significant lack of fit (P = 0.0764), P-value (0.0037) of the model, and satisfactory level of coefficient of determination (R2 = 0.92). For the ω6/ω3 ratio model, R2 and P-value were 0.89 and 0.0132, respectively, but lack of fit was significant (P = 0.0389). The melting point of the produced solid fat was affected by substrate mole ratio, whereas reaction temperature and time had no significant effect. The ω6/ω3 ratio of solid fat was influenced by substrate mole ratio and reaction temperature but not by reaction time. Based on ridge analysis, lower ω6/ω3 ratio was predicted by decreasing substrate mole ratio and reaction time, and by increasing reaction temperature.
CONCLUSIONS: For producing solid fat with a specific melting point of 34.57 °C, a combination of 1:2 (X1), 65.17 °C (X2) and 21.46 h (X3) was optimized, and the optimization was confirmed under the same reaction conditions. The solid fat contained palmitic (37.8%), linoleic (24.8%), oleic (21.3%), and erucic acid (9.7%), and its solid fat content was 30.3% and 10.3% at 20 and 30 °C, respectively. Copyright © 2009 Society of Chemical Industry