Abstract: Response surface methodology (RSM) was applied to optimize the enrichment of α-linolenic acid in silkworm pupal oil by the method of urea adduction fractionation. This optimization was carried out based on our previous investigations on the effects of four process parameters, namely reaction temperature and time, the ratio of urea to fatty acids, and the ratio of 95% ethanol to fatty acids on α-linolenic acid content in urea inclusion compounds by single factor method, and the results showed that the optimum levels of the four parameters were determined to be －8.27 ℃, 8.91 h, 3.39:1 and 10.47:1, respectively. Under the optimum conditions, the content of α-linolenic acid in urea inclusion compounds was up to 70.28%. Urea adduction fractionation is an effective method for the enrichment of α-linolenic acid.

Key words: silkworm pupal oil, α-linolenic acid, urea adduction fractionation