Effect of different processing methods on physicochemical properties, chemical compositions and in vitro antioxidant activities of Paeonia lactiflora Pall seed oils

A research was performed to determine and compare the physicochemical properties, chemical compositions and in vitro antioxidant activities of Paeonia lactiflora Pall seed oils with ultrasonic-assisted solvent extraction, pressing and supercritical fluid extraction. Paeonia lactiflora Pall seed oil contained a high percentage of polyunsaturated fatty acids and monounsaturated fatty acids, especially oleic (31.62-32.88%) and α-linolenic acids (37.55-39.95%). The beneficial multiple dietary phytochemicals (tocopherol, phytosterols and squalene) and in vitro antioxidant activity were significantly influenced by the hull and processing method (P＜0.05). However, higher tocopherol (596.67-738.76 mg/kg) and phytosterols (5775.01-6055.62 mg/kg) contents were found in supercritical fluid extraction oils. Additionally, ten individual polyphenols were quantified, and significantly influenced by the hull and processing method (P＜0.05), with the content of benzoic acid and several individual flavonoids being the higher. According to the results, pressing might be the best process for extracting oil with a high number of polyphenols.

Keywords: Apigenin (PubChem CID: 5280443); Benzoic acid (PubChem CID: 5280805); Chlorogenic acid (PubChem CID: 1794427); Cinnamic acid (PubChem CID: 444539); Free radical scavenging capacity; Individual polyphenol; Kaempferol (PubChem CID: 5280863); Luteolin (PubChem CID: 5280445); P-cumaric acid (PubChem CID: 637542); Pressing; Quercetin (PubChem CID: 5280343); Rutin (PubChem CID: 5280805); Supercritical fluid extraction; Ultrasonic-assisted solvent extraction; Vanillic acid (PubChem CID: 8468).