Formulation and stability of silkworm pupae oil microemulsion

Because of the instability, perishable odor and peculiar smell, a microemulsion system was designed to safely and effectively supply α-linolenic acid from silkworm pupae oil. Microemulsion-loaded silkworm pupae oil was prepared from isoamyl acetate, castor oil polyoxyethylene ether 35 (EL-35), ethanol and water. The optimal microemulsion formulation was a 4% composite oil phase (silkworm pupae oil: isoamyl acetate, 1:2), 16% composite surfactant (EL-35: ethanol, 2:1) and 80% water, with uniformly dispersed spherical particles with diameters of 16.25 nm. The color of the microemulsion was transparent and had no peculiar smell. The investigation results of environmental stress show that the transmittance is 86%–99%, and there is no significant difference from the control group (p > 0.05). Compared with silkworm pupae oil, the total antioxidant capacity of the microemulsion was increased by 7.70 times. Microemulsion-loaded silkworm pupae oil exhibited good physical and antioxidation stability. This work provides a feasible new scheme for ensuring the nutritional and health functions of silkworm pupae oil and supplying α-linolenic acid safely and effectively.