Extraction Process And Antioxidant Activities Of Osmanthus Fragrans Oil

Osmanthus fragrans,a species of Oleaceae,is a famous gardening and aromatic plant.The large number of fruits of O.fragrans every year naturally fall off without being used.The olive oil extracted from the olive fruit of Oleaceae is also known as“liquid gold”.The present study examines three different methods for extracting oil from the fruit of O.fragrans,and analyzes the physical and chemical characteristics,fatty acid composition,and antioxidant properties of the O.fragrans oil.The main results are as follows:?1?The best processing conditions for soxhlet extraction of O.fragrans oil:petroleum ether solvent at60-90?,solid liquid ratio 1:15,extraction time 8 h,extraction temperature 85?.Under these conditions,the oil extraction rate was 39.86%.?2?The best processing conditions for supercritical CO₂ extraction of O.fragrans oil:pressure 30 Mpa,temperature 40?,extraction time 120 min,sieve mesh size 0.37 mm.Under these conditions,the oil extraction rate was 36.58%.?3?The best processing conditions for cold press extraction O.fragrans oil:room temperature,extraction time 60 min.Under these conditions,the oil extraction rate was 11.86%.?4?Physical and chemical properties of the oils extracted by the different methods:density 0.90,0.90,0.90;acid value 0.61 mg/100 g,20.75 mg/100 g,1.62 mg/100 g;iodine value 109.79 g/100 g,117.56 g/100g,112.28 g/100 g;peroxide value 0.069 g/100 g,0.035 g/100 g,0.022 g/100 g;saponification value 179.30mg/g,167.78 mg/g,165.45 mg/g.The acid value of O.fragrans oil extracted by supercritical CO₂ extraction was higher,and the acid value of O.fragrans oil extracted by soxhlet extraction and cold pressing was lower.?5?The extracted oils were methyl esterized and the analyzed via GC-MS.Soxhlet extraction oil is mainly composed of seven fatty acids:palmitic oleic acid?0.10%?,palmitic acid?14.02%?,oleic acid?31.45%?,linoleic acid?47.13%?,stearic acid?4.68%?,arachidic acid?0.18%?,and arachidic oleic acid?0.36%?.Supercritical CO₂ extraction oil is mainly composed of seven fatty acids:palmitic oleic acid?13.46%?,palmitic acid?33.10%?,oleic acid?46.11%?,linoleic acid?0.66%?,stearic acid?4.55%?,arachidic acid?0.19%?,and arachidic oleic acid?0.41%?.Cold pressed oil is mainly composed of seven fatty acids:palmitic oleic acid?0.67%?,palmitic acid?13.89%?,oleic acid?31.83%?,linoleic acid?46.44%?,stearic acid?4.54%?,arachidic acid?0.17%?,and arachidic oleic acid?0.36%?.The O.fragrans oil fatty acids obtained by the three methods have similar types and contents.The relative content of unsaturated fatty acids such as linoleic acid,oleic acid,palmitoleic acid and arachidic oleic acid accounts for about 80%.The relative content of saturated fatty acids such as palmitic acid,stearic acid,arachidic acid and 7-octadecenoic acid accounts for about 20%.Comparison of fatty acid composition and content of O.fragrans oil and five commercially available vegetable oils.The unsaturated fatty acid content is about 80%higher than peanut oil,oleic acid content higher than peanut oil,corn oil,flaxseed oil,sunflower oil,linoleic acid content higher than olive oil,peanut oil,linseed oil,O.fragrans oil has great development value.?6?Cold pressed O.fragrans oil was shown to have the greatest antioxidant activity by hydroxyl radical scavenging,DPPH free radical scavenging,and O₂^-ion scavenging experiments.