Separation And Microencapsulation Of Linoleic Acid In Safflower Oil

Linoleic acid is a kind of necessary fatty acid which is widely used in food industry and medicine producing. The methods of linoleic acid isolation, purification, and micro- encapsulation, stability of the micorencapsuled product are studied in this paper.The safflower seed oil contains about 70-80% linoleic acid and it is very suitable for high content linoleic acid producing: Saponification and acidification procedure can be employed for the preparation of fatty acid mixture from safflower oil, and then, using this fatty acid mixture as raw material, we can get high content linoleic acid via urea fractionation or supercritical CO2 fluid extraction (SFE). The optimum conditions of urea-inclusion crystallization method (UICM) for linoleic acid purification can be drew via an orthogonal design test: the concentration of urea in methanol is 0.3(g/mL), the volume of the solution used for the inclusion is 150ml/20g (urea in methanol/the weight of fatty acid), add the fatty acid mixture into the urea solution and store 24 hours at 10℃, then, separate and dry it. The content of linoleic acid is up to 95.66% and the recovery rate is 93.58%. Repeat the inclusion has no effect on the recovery of linoleic acid so we adopt one-inclusion technoloty.As for the SFE technology, we have tried in 3 different ways: simple column countercurrent extraction, extraction plus fractionation, and double column countercurrent extraction. The result shows that the extraction plus fractionation technology is much better than the two others: the linoleic acid recovery rate is 92.18%, the physical and chemical characters of the products is better than that purified by urea adduction fraction.The linoleic acid is microencapsulated with HI-CAP100, a kind of modified starch, and the spray drying conditions are optimized by response surface analysis(RSA) method using the microencapsulation efficiency and rate of the product as the response value. The optimizing parameters were figured out as follows: the total concentration of the mixture for spray drying was 40%, and then, it was homogenized at 25Mpa, inlet temperature of the heated wind in spray-drying process is 185℃and the outlet temperature is 90℃, thus the microencapsulation efficiency is 93.02%, the rate of the product and the linoleic acid content in it were up to 87.16% and 45% respectively.The moisture content, bulk density and granule size analysis of the 45% linoleic acid content microencapsulation showed that the product contained 2.11% water, the bulk density is 0.39g/ml, and more than 90% production can go thru 60 mesh(280μm) screen;The SEM check showed that the appearance of the microencapsulated linoleic acid is fairly good--smooth and well-encapsulated; The DSC analysis showed that the glassical transition temperature is 60.39℃, which meant that the production had fairly good stablility and it could be stored at room temperature; TGA test of HI-CAP100 showed that the wall material would...