Determination of optimum extraction condition for edible oil and β-carotene from carrot peel (Daucus carota L.) using supercritical carbon dioxide

Abstract

The objectives of this research were to study the optimum condition for extracting oil from carrot peels using supercritical carbon dioxide and find mathematical equations to predict the percentage of oil yield, oil extraction efficiency, and beta-carotene content. Central composite design was performed for 2 factors, temperature (32, 39, 56, 73, and 80 °C) and pressure (14.2, 16.5, 22.1, 27.7, and 30.0 MPa), to determine the optimum oil extraction condition based on the highest value of oil yield, extraction efficiency, and beta-carotene content. It was found that the optimum condition was at 80 °C and 14.2 MPa and when comparing the oil yield, oil extraction efficiency, and beta-carotene content obtained from the experiment at the optimum condition to the values obtained from the prediction with the mathematical model, it was revealed that the deviation value (%D) was less than 10 percent, indicating that the obtained mathematical models could predict the percentage of oil yield, extraction efficiency, and beta-carotene content well. In addition, it was found that the oil from the carrot peels obtained from the experiment was orange with L* a* b* C* and h* at 33.35 26.08 42.28 48.53 and 57.99°, respectively, beta-carotene content iodine value and oil acidity value were 0.27 mg/100mg db, 116.75 mg iodine/100 g oil, and 2.43 mg KOH/g oil, respectively and antioxidant properties based on the ferric-reducing antioxidant power assay was 529.08 µMFe 2+ /g.