Isolation Of Alpha-Linolenic Acid From Bombyx Mori L. Silkworm Chrysalis

The silk industry is a traditional industry in China. It made important contributions to the economic construction of China. Siklworm as the largest part byproduct of silk industry, the actual utilization of is not available.In this research, the mixed fatty acids was prepared from silkworm and the compositions of silkworm lipids were analysised by gas chromatography, high performance liquid chromatography ,thin layer chromatography, and other methods. The results show that lipid content of silkworm was about 32.79% on dry basis. The content on lipids was about 70% ,unsaturated fatty acids, theα-linolenic acid content on unsaturated fatty acids was 32.79%.To purify alpha-linolenic acid (ALA) from silkworm lipids, urea crystallization and argentated silica gel chromatogramphy were employed in this work. Results suggested that fatty acid/urea ratio is key factor for ALA purity and recovery, urea concentration, the crystallization temperature and time are the second. When crystallization was carried at 0°C for 8 h, with fatty acids/ urea ratio of 0.1, urea concentrateion of 30%, ALA percentage increased from 30% to 87%. And the enriched lipid sample was subjected to urea crystallization for the second time, the concentration of ALA did not further increased, and the ALA recovery decreased significantly. After the further isolation of ALA from the enriched lipid by using argentated silica gel chromatography (ASGC), ALA percentage increased to 99%, and recovery of ALA was 63%. So the isolation of high purity ALA from silkworm lipids by urea crystallization then ASGC is feasible.