| Carthamus tinctorius L.is the only cultivated species in the genus of Carthamus and it is a kind of few economic crop with dual-purpose of oil,protein and pigment.The aqueous enzymatic extraction process was optimized with Yunxin No.6 produced in Xinjiang as raw material.Physical and chemical properties,fatty acid composition,contents of polyphenol,flavone and sterols in safflower seed oil compared with the oil under the traditional dip and some other common vegetable oils were analyzed.With the other five kinds of vegetable oil(soybean oil,rapeseed oil and so on)as control group,the antioxidant activity and oxidation stability of safflower seed oil were studied.1.Optimization of aqueous enzymatic extraction process for the production of safflower oil by response surface methodology.The effect of processing parameters,including enzyme type and proportion,ratio of material to liquid,total enzyme amount,extraction time,temperature and pH were investigated on oil yield.Results showed that a mixture of xylanase(UTC-X50),pectinase(NCB3/ZG-040)and alkaline protease(NCB3/ZG-002)(1:2:3,U/U/U)was found to be the most efficient enzyme for the extraction of safflower oil.The maximum yield of 84.68%was obtained as follows:enzyme dose,197.36U/g;material/liquid ratio,1:4(g/mL);performed at pH 4.2,50? for 131min with cell wall polysaccharide enzymes(xylanase and pectinase)and at pH 9.8,40? for 60min with alkaline protease2.Quality evaluation of safflower oil extracted by aqueous enzymatic extraction process.The physical and chemical properties of safflower oil obtained by aqueous enzymatic extraction and solvent extraction were studied.Comparing with peanut oil,sesame oil,soybean oil,walnut oil and rapeseed oil,the fatty acid composition,the contents of minor components in safflower oil were determined.The results showed that the iodine value and unsaponification content of safflower seed oil obtained by aqueous enzymatic extraction were higher than that of solvent extraction and peroxide value of the former was lower than the latter,which indicated the safflower seed oil obtained by aqueous enzymatic extraction had better quality,lower degree of saturation and oxidation.Safflower seed oil was rich in polyunsaturated fatty acids and the content of linoleic acid was 78.98%,which was significantly higher than the other five kinds of vegetable oil.The content of total flavone and sterols in safflower seed oil were 98.82 and 430.06 mg/100g respectively,which was significantly higher than the other five kinds of vegetable oil.The content of polyphenol was 160.14?gGAE/g,less than that of sesame oil.There were no significant effects on the fatty acid composition and sterol content of the safflower seed oil obtained with two methods,but the content of polyphenols and flavone of the safflower oil obtained by aqueous enzymatic extraction was higher significantly than that obtained by solvent extraction.3.Study on antioxidant activity and oxidation stability of safflower seed oil.The antioxidant activity of safflower seed oil was studied through the determination of free radical scavenging activity in vitro.The results showed that the IC50 value of DPPH·scavenging was 11.98mg/mL,less than that of soybean oil and significantly higher than that of rapeseed oil,sesame oil,walnut oil and peanut oil.The IC50 value of ABTS+·scavenging and ORAC value was 9.528mg/mL and 333.38?mol Trolox/g respectively,which were significantly higher than that of the other five kind of vegetable oil.We can conclude that safflower seed oil had a strong scavenging activity against DPPH-,ABTS+ and oxygen radical.The oxidation stability of safflower seed oil was studied by Schall oven test.The results showed that the oxidation stability of safflower seed oil was significantly lower than sesame oil,soybean oil and peanut oil.Its shelf-life could be prolonged from 2 months to 16 months in 20 ? with 0.015%DLTP and 0.005%TBHQ as multiple antioxidants. |
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