The Optimum Process And Physic-Chemical Properties Of Semen Raphani Oil Extracted By Supercritical Carbon Dioxide

Semen Raphani is the dry and mature seed of Raphnaus satirus L.. Research shows that Semen Raphani contains fatty oil and volatile oil. Fatty oil cntains large amounts of erucic acid, linoleic acid, and so on. It is rich in unsaturated fatty acids(especially oleic acid, linoleic acid and linolenic acid), which can enhance the digestive tract movement, treat the senile constipation. Another study shows that linolenic acid has a role in suppression and prevention of colon cancer. However, there is no comprehensive report on Semen Raphani oil extracted by supercritical carbon dioxide.In comprehensive consideration of problems on extracting efficiency, product purity and solvent residual, the study applied supercritical carbon dioxide to extract Semen Raphani oil. According to the yield of product, the research used response surface methodology 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 Semen Raphani.Results of the study indicate as follows:1. The results showed that extraction pressure, temperature, and time have significant influences on the yield of Semen Raphani oil. The optimal process parameters of supercritical carbon dioxide extraction were obtained as follows:comminution granularity300μm, loading150g, extraction pressure33.40MPa, extraction temperature47.80℃, extraction time77.4min, CO2flow rate35Kg-h"1, the first separation pressure8MPa and temperature40℃, the second separation pressure4-6MPa and temperature35℃. Under these conditions, the extraction rate was up to24.90%.2. Compositions of seed oil was identified by GC-MS. The totally fatty acids in the extracts were composed of7.30%saturated fatty acids and92.70%unsaturated fatty acids. Furthermore, erucic acid(34.87%), oleic (26.19%), linoleic (7.84%), and palmitic (3.37%) were found the most abundant fatty acids in Semen Raphani seed oil.3. Semen Raphani oil was transparent and light color. The results showed that the Semen Raphani oil extracted by supercritical carbon dioxide was high purity and good quality.