Abstract: α-Linolenic acid was extracted and purified from sacha inchi oil by β-cyclodextrin inclusion complexation under ultrasonic condition where the efficiency of inclusion complexation could be enhanced. The effect of temperature, ultrasonication time and ratio of β-cyclodextrin to a 2:1 (m/m) mixture of mixed fatty acids prepared from sacha inchi oil and absolute ethanol on the α-linolenic acid content (i.e., purity) of purified product was examined by the one-factor-ata- time method. Subsequently, the operating parameters were optimized using response surface methodology (RSM) with Box-Behnken design and experimentally validated. The highest purity of α-linolenic acid of 59.16% was observed when β-cyclodextrin and the mixture of mixed fatty acids and absolute ethanol were mixed together at a mass ratio of 7.4:1 and then ultrasonicated for 73 min at 60 ℃. In this experiment, a new method for the extraction of α-linolenic acid has been established and our approach can provide useful evidence to optimize the extraction of other fatty acids from sacha inchi oil.

Key words: sacha inchi oil, ultrasonic assisted, α-linolenic acid, β-cyclodextrin, response surface methodology