Abstract: To optimize the extraction technology of different kinds of osmanthus frangrance (OF) seeds oil and to analyze its fatty acid composition,response surface methodology design was employed to optimize the reflux assistance extraction technology of OF seeds oil.Meanwhile,the chemical composition of the fatty acids was analyzed by GC-MS.Moreover,the in vivo antioxidant activities of OF seed oils were also evaluated.The results showed that the optimal extraction conditions for OF var.thunbergii Makino seed (OFMS) oil was the ratio of liquid to solid at 1∶13 mL/g,the extraction time at 80.0 min,and the extraction temperature at 72.0 ℃;the optimal extraction conditions for OF asiaticus Nakai seed (OFNS) oil was the ratio of liquid to solid at 1∶12 mL/g,the extraction time at 80.0 min,and the extraction temperature at 120 ℃;the optimal extraction conditions for OF var.Auranticaus seed (OFAS) oil was the ratio of liquid to solid at 1∶13 mL/g,the extraction time at 60.0 min,and the extraction temperature at 70.0 ℃ and the optimal extraction conditions for OF var.Semperflorens seed (OFSS) was the ratio of liquid to solid at 1∶13 mL/g,the extraction time at 71.0 min,and the extraction temperature at 71.0 ℃.Under the above conditions,the oil extraction yields for OFMS,OFNS,OFAS,and OFSS were 15.0%,17.8%,18.0%,and 16.0%,respectively.Further GC-MS analysis of OFNS and OFAS oils revealed that both of them were abundant in unsaturated fatty acids with a total content of 96.0%,and oleic acid and linoleic acid were the dominate fatty acids in two oils.When the concentration of OF seed oils were 5 μg/mL,the DPPH scavenging ratio of four OF seed oils were more than 79.0%.These results can provide the reference for further development and utilization of OF seeds.

Key words: Osmanthus fragrans seed, fatty acid, response surface analysis, GC-MS, antioxidant activity