Study On Lipase-Catalyzed Synthesis Of Structured Lipids From Conttonseed Oil Winterization Products

Cottonseed oil is an important edible vegetable oils with special functions. Although China’s annual production of a large number of cottonseed oil, cottonseed oil, but processing byproducts have not been fully utilized. In order to increase the added value and the nutritional value of cottonseed oil, this research take winterization products of cottonseed oil as raw materials in the raw material itself retains the beneficial ingredients of conditions to improve their physical and chemical properties, preparation of a low-calorie, high nutritional value of the functional structured lipids.This research studies the structured lipids preparation process, optimizing process parameters. Comparing the deacidification capacity of three kinds of Lye, the results show that aqueous KOH-ethanol deacidification best;Lipozyme RM IM lipase that have the best catalytic effect was selected from three kinds of Sn-1,3position immobilized lipases. The effects of reaction time, reaction temperature, enzyme dosage and substrate ratio on the enzymatic catalysis were studied, take the content of caprylic acid in the final structured lipids as the standards for evaluating the merits of process.Through mono-factor experiment to determine the optimum conditions.Four factors scope respectively are:reaction temperature60℃,reaction time10h, enzyme load10%,substrate ratio2:1.Mono-factor experiment and response surface analysis were used to optimize process parameters,according to experimental data the quadratic polynomial model using content of caprylic acid as response value with the factors(reaction temperature,reaction time, enzyme load,substrate ratio) was established,and significance test for this model.Optimal conditions were determined as follows:reaction temperature74℃, reaction time15.30h, enzyme load12%(by substrate weight), substrate ratio4:1(caprylic acid/cottonseed oil winterization,mole of ratio). In this condition, the prediction value of caprylic acid in the sructure lipid content is45.9872%.Using the best technology to expand the experimental conditions, before the modification of cottonseed oil winterization products and modified lipid structures were physicochemical characteristics of the detection and analysis of fatty acid composition respectively. The results show that the modified structured lipids are light yellow liquid, have better taste,Lovibond color and transparency;have less content of moisture volatiles,peroxide value,acid value,iodine value,and the melting point depressed;the smoke point obviously increased,and none of residual solvent in the structured lipids.These phenomena are fully explained,that enzymatic reaction have good effect to improve the winterization products of cottonseed oil physicochemical properties.Analysing the fatty acid composition in the pre-and post oils, the results show th-at the modified structured lipids have rich bitterness45.64%and30.18%linoleic aci-d, and greatly reduced levels of long-chain palmitic acid,stearic acid and other satura-ted fatty acids.Caprylic acid and linoleic acid have special effects in human body,wh-ich have special effects in reduce cholesterol content in the blood,to prevent atherosc lerosis,hypertension,hyperlipidemia,and so on.So initially determined the structure of th-e lipid-modified more nutritional value. This research has important value for oil dee-p processing technology and improving the added value of the products.