Decompressing Inner Ebullition Extraction (DIEE) of Crude Polysaccharides from Adlay Seed Oil Extracted Residues Using Plackett–Burman Design and Response Surface Methodology

A simple and efficient decompressing inner ebullition extraction techniquewas employed for the extraction of crude polysaccharides from adlay seed oil extractedresidues. A two-level Plackett-Burman design method was applied to identify the influencingdegree of factors for the polysaccharides yield, then a path method of steepestascent was undertaken to determine the range of the optimal value of important factors,and finally response surface methodology with a Box-Behnken design was employedto evaluate their optimal levels and also to investigate the interactions between the significantfactors. The optimal conditions were developed as the ratio of aqueous ethanolsolutions to raw material of 3.88 mL/mg, mass concentration of aqueous ethanol solutionof 70%, immersing time of 30 min, ratio of hot water to raw material of 37.83 mL/mg,operating gauge pressure of –0.082 MPa, extraction time of 5.99 min, and extractiontemperature of 80°C, respectively. Under the optimal conditions, the highest yield of thecrude polysaccharides was achieved at 6.78 %, which was very close to the predictedvalues (6.54%) obtained from the selected model. It was summarized that decompressinginner ebullition extraction method coupled with both Plackett–Burman design andresponse surface methodology is an effective way for the maximum extraction of crudepolysaccharides from adlay seed oil extracted residues, which even could be extendedfor the isolation of other natural products in separation science.