Modeling of Rice Bran Oil Yield and Bioactive Compounds Obtained Using Subcritical Carbon Dioxide Soxhlet Extraction (SCDS)

Subcritical carbon dioxide Soxhlet extraction (SCDS) is an innovative green technology that has been proven capable of extracting 10 times more bioactive compounds than hexane in rice bran oil extraction. As this technology has commercialization potential, understanding the extraction behavior and modeling the extraction curves are essential. In this study, the extraction kinetics of rice bran oil and its bioactive compounds, namely, alpha-, beta-, gamma-, and delta-tocopherol; alpha-, gamma-, and delta-tocotrienol; and gamma-oryzanol, are discussed and modeled using the diffusion model (DM), logistic model (LM), and simple single plate model (SSPM). Overall, the extraction rate of the oil yield and bioactive compounds was halved after 7 h of extraction. After 15 h of extraction, up to 94.24% of the extractable total tocopherol and 91.79% of the extractable total tocotrienol were extracted. The SSPM is recommended for modeling oil yield and oryzanol, while LM is suitable to model tocopherols and tocotrienols.