Study On Supercritical CO₂ Extraction And Antioxidant Activity Of Magnolia Officinalis Rehd.Et Wils.Seed Oil

As one of the three largest woody medicinal plants in China,Magnolia officinalis Rehd.et Wils.has great market demand,wide medicinal value,great development potential and good long-term benefit at home and abroad.The seeds of M.officinalis are dried seeds after ripening,which have high oil content in normal and full state,can be used to extract oil or make soap.The seeds of M officinalis have the effect of digestion and eyes in traditional Chinese medicine.It can be used to treat symptoms such as discomfort in the stomach.At present,the comprehensive exploitation and utilization of M officinalis seed is low,and the related research and reports are few.In this paper,the supercritical CO2 extraction technology of M officinalis seed oil was studied,the effective components,physicochemical properties and antioxidant activity of different M.officinalis seed oil were detected and analyzed.To provide some valuable reference for the future research and comprehensive development of M officinalis.1.In this experiment,the seed oil of M.officinalis was extracted and separated by supercritical CO2 extraction.On the basis of single-factor experiment with multi-factor co-existence,the response surface optimization method was used to study the related parameters which caused many effects on the oil yield in the extraction process.Through the interaction of response surface,the regression equation was established and the influence parameters in supercritical CO2 extraction process of M.officinalis seed oil were optimized.The optimum conditions for extracting M officinalis seed oil were obtained as follows:pressure is 34MPa,temperature is 41?,time is 130min.The theoretical oil yield of M officinalis seed is 21.8252%and the actual oil yield is 21.579%.The difference between them was 0.246%.2.The different kinds of seed oil of M.officinalis were extracted under the optimum extraction conditions,their physical and chemical properties were tested and analyzed.The seed oil of "officinalis subsp.biloba was lighter than that of M.officinalis seed oil,and all of them were clear and transparent,which are 0.862g/mg,0.893g/mg and 0.0701%,0.0698%.After data analysis,the relative density,water content and volatile content of seed oil of two kinds of M.officinalis were similar,but acid value,iodine value,saponification value and peroxide value were higher than those of M.officinalis.The acid value was 53.973 mg/g,61.306 mg/g;the iodine value was 100.813g/100g,102.226g/100g;the saponification value was 186.944 mgKOH/g,193.463mgKOH/g;the peroxide value was 0.030mmol/kg,0.140mmol/kg.The difference may be due to the higher content of unsaturated fatty acids in M officinalis subsp.biloba seed oil than in M.officinalis.3.GC-MS was used to detect and analyze the components of different species of M.officinalis,seed oil,and the differences were compared.Both M officinalis,seed oils contain higher unsaturated fatty acid methyl esters,the relative content can be more than 60%,and the M.officinalis subsp.biloba is relatively high.At the same time,both of them are mainly linoleic acid methyl ester and methyl oleate,followed by methyl palmitate,the relative content of three fatty acid methyl esters can reach more than 70%,and also contains a small amount of methyl linoleate.Methyl bromide,methyl behenate,methyl methanepentate,methyl stearate and methyl linolenate.The difference in the type and relative content of the fatty acid methyl esters contained in the two indicates that the species and geographical differences affect the composition of the fatty acids.4.The scavenging ability of DPPH,ABTS,hydroxyl radical and the reduction ability of iron ion in different kinds of seed oil of M officinalis were detected and analyzed,so as to determine the antioxidant activity of seed oil.When the concentration reached 2.0mg/mL,M officinalis seed oil and M,officinalis subsp.biloba seed oil had the strongest ability to reduce three kinds of free radicals and iron ions,which were 84.45mg/mL,84.35mg/mL;55.60mg/mL,47.29 mg/mL;81.50 mg/mL,79.38 mg/mL;0.2219 mmol/L,0.2167 mmol/L.The results showed that the seed oil of M.officinalis had certain antioxidant capacity,and the seed oil of M.officinalis was stronger,both of them were lower than Vc.Therefore,the two kinds of M.officinalis seed have important functions in medicine,food,etc.,especially the large amount of unsaturated fatty acids contained in it,which is beneficial to human health and thus shows its development and utilization value.