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The diacylglycerol been widely used in industrial fields such as food, cosmetics and pharmaceuticals. Also found in recent years, diglycerides have to reduce the body lipids, visceral fat reducing effect, and the role of inhibition of weight gain. Diglyceride in the natural fats and oils content is low, therefore, the diglyceride synthesis technology increasingly widespread attention at home and abroad. Currently, diglyceride synthesis methods are mainly the chemical method and the enzymatic method. Compared to chemical catalysts, enzymes as biocatalysts, mild reaction conditions, low energy consumption, little environmental pollution, as well as a good area and location of the advantages of selectivity, and the by-product of the process of enzymatic synthesis of diacylglycerol, diacylglycerol high purity, good color. Enzymatic production of diacylglycerol, therefore, has become one of the hot areas of research, such as food and medicines. This thesis focuses on the lipase-catalyzed solvent-free systems bitterness and glycerol preparation glycerol diester its purification process system. The main contents are as follows: 1 fat from three sources and immobilized enzyme Novozyme 435, Lipozyme RM IM and Lipozyme TL IM screened Novozyme 435 best enzyme catalysts. Novozyme 435 as catalyst, octoate and glycerol direct esterification without a solvent system synthesis of glycerol diester process parameters. The single factor experiments investigated the the different dehydration ways substrate molar ratio, reaction temperature, enzyme dosage, reaction time, the initial amount of water and other factors bitterness conversion and diacylglycerol. On this basis, the use of response surface methodology to optimize the process parameters established bitterness diacylglycerol product regression model equation, to obtain the optimum process conditions: substrate molar ratio of 1.99:1, reaction temperature 51.5 oC enzyme 3.05%, the reaction time of 6.29 h. Measured diacylglycerol content In this under optimal conditions, up to 71.9%, 71.3 ± 0.88% content with the model prediction is very consistent, and prove that the model is reasonable and reliable. 3 silica gel column chromatography separation and purification caprylic diglyceride technology. Thin layer chromatography through silica gel plates from six eluent (chloroform - acetic acid esters, chloroform - methanol, n-hexane - acetic acid, petroleum ether - isopropanol, petroleum ether - n-butanol, and petroleum ether - anhydrous ether) in the initial screening of the petroleum ether - of anhydrous ether system for optimal mobile phase. Investigated in petroleum ether - anhydrous ether elution system of petroleum ether - anhydrous ether solution ratio, flow rate, sample volume of elution effect. The results show that when the loading amount of 4 g, and a flow rate of 2.5 ml / min, a non-continuous gradient elution 4.5:1,0.5:1 (v / v) petroleum ether - anhydrous ether solution, better separation, caprylic diacylglycerol purity of 94%, a return rate of 90%. Chromatographic conditions, the silica gel column using 5 times repeated, and the purity of the product remains at more than 90%, and the recovery is substantially maintained in more than 85%, and has good stability in operation.
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