Grasas y Aceites, Vol 69, No 3 (2018)

Microwave-assisted extraction of non-polar compounds from pistachio hull and characterization of extracts

H. N. Özbek
Department of Food Engineering, Faculty of Engineering, University of Gaziantep, Turkey

D. Koçak Yanık
Department of Food Engineering, Faculty of Engineering, University of Gaziantep, Turkey

S. Fadıloğlu
Department of Food Engineering, Faculty of Engineering, University of Gaziantep, Turkey

H. Keskin Çavdar
Department of Food Engineering, Faculty of Engineering, University of Gaziantep, Turkey

F. Göğüş
Department of Food Engineering, Faculty of Engineering, University of Gaziantep, Turkey


Soxhlet and microwave assisted extraction (MAE) methods were used to obtain non-polar compounds from pistachio hull. MAE parameters (liquid to solid ratio, microwave power, and extraction time) were studied to obtain maximum extraction yield. The optimal conditions were found to be liquid to solid ratio of 15:1 (v/w), microwave power of 250 W and extraction time of 12.5 min. The extraction yields were 9.81 and 9.50% for MAE and Soxhlet methods, respectively. The total phenolic content, antioxidant activity and tocopherol content of the extract obtained by MAE was found to be significantly higher than those of the Soxhlet extract (p < 0.05). The results showed that the extract contained α-tocopherols (567.65 mg/kg) and oleic acid (48.46%) as the major tocopherols and fatty acids. These findings propose that hull extracts can be considered as a good source of natural bioactive compounds and MAE can be a good alternative to the traditional Soxhlet method.


Antioxidant activity; Fatty acids; Microwave assisted extraction; Pistachio hull; Tocopherols; Total phenolic content

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