Wei Shi's research while affiliated with Guangdong Academy of Agricultural Sciences and other places

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.

In this study, α-linolenic acid-enriched diacylglycerols (ALA-DAGs) were prepared via a two-step enzymatic way by combi-lipase using silkworm pupae oils as substrates. Firstly, several factors including temperature, mass ratio of water to oil, pH and enzyme loading were optimized for the hydrolysis of silkworm pupae oil. The maximum fatty acid content (96.51%) was obtained under the conditions: temperature 40 °C, water/oil 3:2 (w/w), pH 7, lipase TL100L loading 400 U/g, lipase PCL loading 30 U/g. Then, ALA was enriched by urea inclusion, with an increased ALA content of 82.50% being obtained. Secondly, the ALA-enriched silkworm pupae DAG oil (SPDO) was prepared by lipase PCL-catalyzed esterification reaction. After molecular distillation, the final SPDO product contained contents of DAGs (97.01%) and ALA (82.50%). This two-step enzymatic way for production of ALA–DAGs was successfully applied in a 100-fold scale-up reaction. Overall, our study provides a promising way for the preparation of ALA–DAGs.

A comprehensive identification of lipid compositions and tocochromanols in Antheraea perny i ( A. perny i) and Bombyx mori ( B. mori ) pupae oil is reported in the present study. Fatty acid profiling shows that both oils contain high levels (79.67% vs 71.11%) of unsaturated fatty acids, especially linoleic acid and linolenic acid. Moreover, linolenic acid is preferentially enriched at the sn ‐2 positions of triacylglycerols (TAGs). Liquid chromatograph‐mass spectrometry (LC‐MS) analysis demonstrates that POO (TAG with one palmitoyl and two oleoyls) is the primary TAG form with percentages of 20.18% in A. perny i and 15.00% in B. mori . The dominating phospholipid species are phosphatidylcholine (PC, 30.40% vs 54.61%) and phosphatidylethanolamine (PE, 34.82% vs 20.39%). Four sterol constituents with total contents of 382.56 ± 3.12 and 371.65 ± 2.98 µg g ⁻¹ are identified and analyzed quantitatively. Additionally, the levels of tocochromanols (20.15 ± 0.89 vs 17.15 ± 0.71 mg g ⁻¹ ) are quantified in both silkworm pupae oils. Overall, silkworm oil acts as an enriched source of functional lipids and tocochromanols. Practical Applications : A systematic investigation on the principal lipid classes and tocochromanols of Antheraea perny i pupae and Bombyx mori pupae oil is reported in this study. The informative data provide supporting evidence for comprehensive utilization of silkworm oil for production of nutritional and healthy products.