山核桃亚油酸分离及共轭亚油酸制备技术分析-separation of linoleic acid from carya cathayensis and analysis of preparation technology of conjugated linoleic acid.docx

PAGE PAGE IV Abstract Conjugated linoleic acids (CLA) are unique unsaturated fatty acids with various important biological and physiological functions. Their functionality and applications in foods, pharmaceuticals, cosmetics, and other industries have become hot research topics.However, the amounts of naturally occurring CLA are too little to satisfy the demands of people. At the present, chemical synthesis methods are an effective way to obtain large quantity of CLA, and alkali isomerization technique to prepare CLA is simpler and practical. This method synthesizes CLA using linoleic acid or plant oil with high content of linoleic acid as starting material by the isomerization. Carya cathayensis Sarg. oil contains abundant unsaturated fatty acid, especially oleic acid and linoleic acid, so it can provide raw material for the preparation of CLA. This study was carried out to research the extraction of linoleic acid from Carya cathayensis Sarg. oil, the separation and purification technology, oxidation stability and antioxidant activity of CLA to develop a new way for intensive processing of Carya cathayensis Sarg. The results were as follows: Both single factor and orthogonal experiments were used to optimize conditions for the separation and purification of linoleic acid from Carya cathayensis Sarg. oil by urea adduction fractionation. Effects of adduction temperature, time, the ratio of fatty acid to urea (W/W), and methanol to urea (V/W) on the purity and yield of linoleic acid were investigated. The results showed under the optimal purification conditions with the ratio of fatty acid and urea at 0.4, the rate of methanol and urea at 4, adduction temperature at -5℃, and adduction time of 24h, the content and yield of linoleic acid in Carya cathayensis Sarg. oil were 60.27% and 40.16%, respectively. Effects of related factors on the alkali isomerization of linoleic acid were investigated. Factors of reaction time, temperature, and the weight ratio of the linol