Response surface optimization of ultrasound-assisted oil extraction from autoclaved almond powder

An investigation into Ultrasound-assisted extraction and autoclaving pretreatment was conducted for the oil extraction from almonds. The best possible combination of extraction parameters was obtained with the response Surface methodology (RSM), at a three-variable, three-level experiment Box-Benken design (BBD). The Optimum extraction parameters were as follows: extraction time, 55 min: extraction temperature, 51 degrees C: and solvent/sample ratio, 19:1, at a fixed ultrasonic frequency of 40 kHz and power of 150 W. Under these conditions, the oil recovery was 81.89 +/- 0.23% for the autoclaved almonds, which well matches with the predicted value. Furthermore, the oil composition was analyzed with GC-MS, and the effect of the autoclaving on the oil extraction was evaluated. The results showed that the autoclaving pretreatment increased the oil recovery, without affecting the oil composition, by 8.69%, which confirmed the efficacy of the autoclaving oil the oil extraction from almond powder. (C) 2009 Published by Elsevier Ltd