Silvia MIRONEASA1, and Costel MIRONEASA2*
1 Faculty of Food Engineering, Ştefan cel Mare University of Suceava, 13th University Street, 720229,
Suceava, Romania
2 Faculty of Mechanical Engineering, Automotive and Robotics, Ştefan cel Mare University of Suceava,
13th University Street, 720229, Suceava, Romania
*Corresponding author: costel.mironeasa@usm.ro
Abstract
The hazelnuts represent important widely consumed tree nuts from the mountain areas in many countries, appreciated for their nutritional composition and valuable oil quality given by unsaturated fatty acids, especially oleic (80%) and linoleic (6%–12%) acids. Due to its bioactive substances, hazelnut oil is used in different fields of industry, such as food, pharmaceuticals, and cosmetics. Various methods were applied to hazelnut oil extraction, but finding alternative eco-friendly methods to obtain a high oil yield and high-quality extracted oil become a current issue. One of these methods consists of mechanical pressing assisted by ultrasound. A new device designed for oil extraction from oilseeds which includes a transducer with ultrasound and a concentrator that ensures uniform pressures throughout the mass undergoing extraction can be applied to improve hazelnut oil extraction yield. To carry out the extraction, the hazelnuts are heated beforehand to a temperature of approximately 70 C, the extraction mechanical pressure is in the range of 25-30 MPa, and the amplitude of the acoustic signal from the ultrasound generator transducer, 60 – 100 m. During the extraction, the pressing zone ensures a temperature of 70 – 90 C. Constructive elements and proposed extraction parameters ensure the optimization of the ultrasound-assisted extraction process. The performance features of this device make its use feasible for oil extraction from hazelnuts and allow for increasing the extraction yield of oil, being suitable for industrial production.
Keywords:
hazelnut; hazelnut oil; oil extraction methods; mechanical pressing; ultrasounds