In general, there are three methods for extracting oil from various sources: mechanical, solvent, and pre-press-solvent. Each of these methods has its own advantages and disadvantages, with extraction efficiency depending on key factors such as the extraction technique, the properties of the plant component matrix, and the solvent used. Factors like temperature, pressure, and time also play a role. Researchers have consistently sought to replace or complement these methods to reduce residual oil in products. This study introduces new oil extraction methods that have gained attention in recent years, including the microwave, pulsed electric field, ultrasound, supercritical fluid, enzymatic, ohmic, and combined methods to enhance efficiency. The research demonstrates that these methods increase oil extraction efficiency and bioactive compound extraction from plant sources, resulting in improved oil quality. Most methods also reduce extraction time, offering researchers and industrialists a variety of options for their oil extraction needs. However, the study notes contradictions in the results, such as varying acidity levels in the oil, which may be attributed to raw materials and study conditions. In the end, it was determined that ultrasound, pulsed electric field, and enzyme methods can be used industrially to extract oil from olives, while supercritical fluid can be used to extract oil from certain seeds.

In industrial soybean lecithin production, process variables such as temperature, water content, agitation, and processing time play a critical role in determining the final product quality. Despite their importance, the combined effects of these parameters under industrial-scale conditions have not been sufficiently quantified. Therefore, this study systematically evaluated the influence of processing temperature (70–80 °C) and water content (1.5–3% w/w of oil) on key quality attributes, including lecithin moisture content, purity, acidy number, and peroxide value, as well as soybean oil acidity and insoluble fine substances. A response surface methodology (RSM) approach was applied to model the relationships between variables and to identify optimal processing conditions. The results indicate that an increasing temperature reduces lecithin moisture content, likely due to enhanced water evaporation and improved phase separation, while simultaneously increasing peroxide value and oil acidity (p < 0.05), possibly because of accelerated lipid oxidation and hydrolysis. Lecithin purity improved up to 75 °C, indicating more efficient separation, but decreased at higher temperatures, suggesting thermal degradation or emulsification effects. Similarly, increasing water content led to higher moisture, peroxide value, and acidy numberin lecithin, as well as increased acidity and insoluble fine substances in soybean oil (p < 0.05), which can be attributed to excessive hydration promoting emulsion stability and entrainment of oil-phase impurities into the lecithin fraction. Process optimization indicated that a water content of 1.5% and a temperature of 73.93 °C yielded the highest overall product quality, with a desirability value of 0.874.