Production of lipase‐catalyzed solid fat from mustard oil and palm stearin with linoleic acid by response surface methodology

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) ( X 1 ), reaction temperature ( X 2 ) and reaction time ( X 3 ). 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 ( R 2 = 0.92). For the ω6/ω3 ratio model, R 2 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 ( X 1 ), 65.17 °C ( X 2 ) and 21.46 h ( X 3 ) 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