Abstract:

To improve the extraction yield of high-quality almond oil with low residual oil and reserve high natural activity in protein cake, an extraction method combining hydraulic pressing of almond with alcohol soaking-pressing of almond cake was explored. Almond was pressed at an 8-16-24-32-48-64 MPa static pressure gradients for 30 min, and then the obtained almond cake was soaked in 95% alcohol solution for 20 min, followed by the second pressing at an 8-16-24-32-48 MPa pressure gradients for 20 min. Results showed that the almond oil extraction yield is 74.15% by primary pressing, and the residual rate of oil in the cake is 23.99%. In the alcohol soaking-pressing stage, the best solid-liquid ratio is 3.5:1 (m/m), and the oil extraction yield reaches 62.53%, while the residual rate of oil is reduced to 10.57%. In conclusion, using the method of combining hydraulic pressing with alcohol soaking-pressing, the total extraction yield of almond oil reaches 90.32%.

Key words: almond, press, extraction yield, alcohol, soaking