Subcritical butane extraction of oil and minor bioactive components from soybean germ: Determination of migration patterns and a kinetic model

Abstract For the aim of determining the migration patterns and extraction kinetics of the oil and minor bioactive components during subcritical fluid extraction (SFE) process from soybean germ, the extraction efficiency was investigated at different temperature and time with butane as solvent. The results indicate that flaking treatment is beneficial to the release of soybean germ oil (SGO) and bioactive components. The chosen models (So and Macdonald's model for SGO, Baümler's model for bioactive components) were found to be in good agreement with the experimental data and could be used to explain the SGO and bioactive components migration during SFE process. Furthermore, the activation energy of phytosterols, tocopherols, and phospholipids were 13.42, 12.23, and 22.72 kJ/mol, respectively. In conclusion, high‐quality SGO that contain high levels of phytosterols (26.51 mg/g) and tocopherols (2.29 mg/g) and a lower content of phospholipids (26.68 mg/g) can be obtained with an extraction at 60 °C for 45 min. Practical applications In this study the effects of pretreatment of SG, solid/liquid ratio, extraction temperature and time on the yields of SGO and minor bioactive components were investigated. Simultaneously, the migration patterns and kinetic models of SGO and minor bioactive components described the subcritical butane extraction process accurately. Therefore, the research provided a theoretical support for the pretreatment of raw materials and the parameters control of subcritical extraction of soybean germ oil. The study can guide the popularization and application of subcritical fluid extraction for soybean germ oil extraction effectively. At present, the technology is ready for technical transformation in Henan subcritical fluid extraction company.