Modeling and Optimization of Safflower Seed (Carthamus tinctorius L.) Alkaline Pretreatment Parameters to Increase Oil Yield

Safflower seed is a valuable source of vegetable oil. Despite current advances in processing technology, the oil extraction efficiency during cold pressing remains relatively low, which is attributable to the seed morphology and the dense seed hull that acts as a barrier. Traditional oil extraction methods are relatively inefficient; therefore, considerable attention is focused on seed pretreatment prior to oil pressing, as this stage plays a critical role in the overall oil production process. The possibility of increasing oil yield by treating safflower seeds prior to pressing was studied using response surface methodology (RSM). Three factors were investigated: NaOH solution concentration from 1% to 2%, treatment temperature from 40 °C to 60 °C, and treatment time interval from 40 min to 60 min. A Box–Behnken design was applied to evaluate the effect of the three independent variables on oil yield. Following a series of experiments, the RSM tool was applied, which identified the optimal pretreatment parameters: NaOH concentration—1.64%, temperature—53.54 °C, and duration—51.11 min. The predicted oil yield was 20.5%, while the experimentally determined oil yield under optimal conditions reached 21.47%. The application of response surface methodology increased the oil extraction efficiency by 37.52%.