Extraction And Analysis Of Chemical Components Of Brassica Rapa L. Seeds Oil By Supercritical Carbon Dioxide

Brassica rapa L. seed is the dry and mature seed of Brassica rapa L., which is a centuried traditional Chinese medicine recorded in "Compendium of Materia Medica". Researches show that Brassica rapa L. seed contains12amino acids which contain7essential amino acids. There are isothiocyanate and nenitrile in essential oil of Brassica rapa L.. However, there is no comprehensive report on extraction process, qualitative and quantitative analysis of chemical compositions, as well as physicochemical properties of Brassica rapa L. seeds oil.In comprehensive consideration of problems on extracting efficiency, product purity and solvent residual, the study applied supercritical carbon dioxide to extract Brassica rapa L. seeds oil. According to the yield of product, response surface methodology was used to optimize the extraction process and determined the optimal parameters. At the same time, physicochemical properties and fatty acid compositions were measured, so as to supply theoretical foundation on comprehensive utilization of Brassica rapa L. seeds.Results of the study indicate as follows:1. The results showed that extraction pressure, temperature, and time have significant influences on the yield of Brassica rapa L. seeds oil. The optimal process parameters of supercritical carbon dioxide extraction were obtained as follows:loading100g, comminution granularity300μm, extraction pressure31.65MPa, extraction temperature46.10℃, extraction time80.40min, CO2flow rate40kg·h-1, the first separation temperature40℃and pressure8-9MPa, the second separation temperature35℃and pressure is tank pressure. Under these conditions, the maximum extraction rate was32.55%.2. Identified by gas chromatography-mass spectrometry, fatty acids in the oil were composed of7.99%saturated fatty acids and92.01%unsaturated fatty acids. Saturated fatty acids mainly included hexadecanoic acid(2.63%), Unsaturated fatty acids were rich in erucic acid(47.18%), oleic acid(14.26%), cis-11-Eicosenoic acid(10.71%) and linoleic acid(8.43%).3. Brassica rapa L. seeds oil was transparent and light color. The results showed that the Brassica rapa L. seeds oil extracted by supercritical carbon dioxide was high purity and good quality.