Preliminary Evaluation On Extraction Technology And In Vitro Biological Activities Of Blue Honeysuckle Seed Oil

Blue honeysuckle(Lonicera caerulea L.var.edulis Turcz.ex Herd.),an edible wild berry which located in northeast area of our country,has abundant nutritional value and medicinal value.At present,people consume blue honeysuckle mainly by the approach of fruit juice or fruit wine.The pomace containing fruit seeds,fiber,protein and other ingredients were discarded,resulting in a waste of blue honeysuckle resources.Different plant seeds have different contents of seed oil,and there is little research on blue honeysuckle seed oil at this stage.Therefore,using the fruit seeds from blue honeysuckle pomace as raw materials,blue honeysuckle seed oil was extracted,analyzed and detected.The seed oil was extracted by the enzyme-microwave extraction method,and the extraction process was optimized taking the oil yield as an indicator.The fat compositions and relative contents of blue honeysuckle seed oil were analyzed by GC-MS technology,the physical and chemical parameters of the oil were measured,and its thermal stability and oxidative stability were investigated.Finally,the in vitro biological activities of blue honeysuckle seed oil were evaluated,including antioxidant activity,cytotoxicity,lipid-lowering activity and liver protection.The main results of this research are as follows:1.The process of extracting blue honeysuckle seed oil by enzyme-microwave extraction method is established.The best process is that alkaline protease with a concentration of 2%,and firstly mix it with blue honeysuckle seed powder under optimal conditions(pH 10,water bath 50?)enzymatic hydrolysis reaction for 2 h,and then microwave extraction with absolute ethanol as the extraction solvent,liquid-solid ratio of 20 mL/g,microwave power of 500 W,microwave temperature of 51 ? and microwave time 20 min.At these circumstances,the best oil yield is 29.67±0.04%.The optimized oil yield of this method is close to 30.5%of the Soxhlet extraction method,and it has the advantage of green extraction.2.The fatty acid composition of blue honeysuckle seed oil was analyzed and determined.The main fatty acid components of blue honeysuckle seed oil by Soxhiet extraction method and enzyme-microwave extraction method are conjugated linoleic acid,namely 9,cis-11,trans-octadecadienoic acid and 10,trans-12,cis-octadecadienoic acid,and the both contents are more than 45%.By comparing the physicochemical indexes of the oils in the two extraction methods,it was found that the acid value and peroxide value of blue honeysuckle seed oil extracted by the enzyme-microwave extraction method were lower than that of the Soxhlet extraction method,meanwhile,the iodine value and saponification value were almost no differences from the Soxhlet extraction method.The TG analysis of the two methods showed that there was no significant difference in thermal stability.The oxidation stability test displayed that the CD value and POV value of the seed oil of the enzyme-microwave extraction method are relatively more stable during the test time.Therefore,the quality of blue honeysuckle seed oil extracted by enzyme-microwave extraction method is higher than that of Soxhlet extraction method.3.The in vitro biological activity of blue honeysuckle seed oil has been studied.In vitro DPPH and ABTS free radical scavenging experiments showed that it has strong antioxidant activity,no cytotoxicity to liver cells L02 within the concentration range of 100 ?g/mL.It shows lipid-lowering activity at a concentration of 40 pg/mL,which can inhibit sodium oleate-induced adipogenesis in HepG2 cells,reduce total cholesterol and triglyceride levels,and also have a liver protective effect.In summary,this study established an efficient and green extraction process for extracting blue honeysuckle seed oil by enzyme-microwave method.Compared with the traditional Soxhlet extraction,the seed oil extracted by this method has better quality and stronger stability.And blue honeysuckle seed oil is safe and non-toxic,with antioxidant activity,lipid-lowering activity and liver protection effect This research has laid the foundation for the efficient utilization of blue honeysuckle resources.The functional and health-care oil obtained from blue honeysuckle seeds has the potential for industrial development.