Process optimization for the enrichment of α-linolenic acid from silkworm pupal oil using response surface methodology

-Linolenic acid (ALA) was widely used in food and pharmaceutical industry, as an important medical material. In the present study, the mixed fatty acids (MFAs) extracted from desilked silkworm pupal oil were used raw materials for enriching ALA, using urea clathration method; their preparation process was optimized by response surface methodology (RSM). The research results indicated that the enrichment of ALA produced, by using urea clathration method from desilked silkworm pupal oil was effectively enhanced by RSM. Three parameters of the process for enriching ALA were optimized as follows, using RSM: the ratio of saturated urea/EtOH solution to MFAs was 2:1 (v/v); clathration temperature, 4°C and clathration time, 2 h. The adequately high R2 value, 0.9674 (adjusted R2 = 0.9086) indicated the statistical significance of the model. The purity of ALA after optimization was 31.87%, while predicted value, 35.60%. In conclusion, enrichment conditions optimization to enhance purity of ALA from the MFAs of desilked silkworm pupal oil can be easily and effectively done by RSM. The developed enrichment process of ALA indicated desilked silkworm pupal oil as a potential raw material for producing ALA.