Production and characterisation of high-quality silkworm pupal oil for omega-3 fatty acid supplementation

Abstract

The present work aimed to produce edible oil that is low-cost and rich in ω-3 fatty acids (mainly α-linolenic acid; ALA). Silkworm pupae are industrial wastes which could be a good choice as the raw material for silkworm pupal oil (SPO) is. Solvent extraction (SE), supercritical fluid extraction (SFE), and aqueous enzymatic extraction (AE) were compared (oil yields of 28.34, 26.75, and 23.11%, respectively), and crude SPOs showed similar fatty acid compositions. Crude SPO extracted by SE contained a total tocopherol of 289.56 µg/g, which was higher than that of AE. SE was recommended due to its low cost, high oil yield, and high preservation of bioactive compounds, and a further refinement process was adopted only for crude SPO from SE. The fatty acid composition of the refined SPO was not different from that of the crude SPO, which contained 37.51% ω-3 fatty acids. A low acid value (AV, 0.65 mg KOH/g) and peroxide value (PV, 5.79 meq O2/kg), with almost no detectable toxicants indicated that SPO would be a high-quality edible oil for ω-3 fatty acid supplementation.