Abstract: It has been reported that peony seed oil is rich in α-linolenic acid and fat-soluble companions. Different extraction methods have significant effects on the quality and bioactive ingredients of peony seed oil. In this paper, peony seed oils were prepared by five different methods (aqueous enzymatic extraction, microwave-assisted aqueous enzymatic extraction, aqueous extraction, cold pressing, and solvent extraction), and their physicochemical properties, shelf life, fat-soluble concomitant contents, and volatile components were evaluated. The results showed that the acid and peroxide values of the oil obtained by aqueous enzymatic extraction were relatively low. Among the five oils, this one had the longest shelf life of 4.67 h, and exhibited the highest retention rate of fat-soluble concomitants (γ-tocopherol content of 45.787 mg/100 g, squalene content of 8.925 mg/100 g, and β-sitosterol content of 293.55 mg/100 g). In addition, the volatile components common to the five oils included aldehydes (α-methylcinnamaldehyde and hexanal), esters (ethyl palmitate), and hydrocarbons (octadecamethyl cyclononasiloxane and other alkanes). Among these oils, the one prepared by cold pressing contained the largest number of volatile components while the smallest number was found in the one obtained by solvent extraction. To sum up, the peony seed oil obtained by aqueous enzymatic extraction had the best the quality.

Key words: peony seed oil; extraction methods; physicochemical properties; fat-soluble concomitants; volatile components