Intensification of the SFE Using Ethanol as a Cosolvent and Integration of the SFE Process with sc-CO2 Followed by PLE Using Pressurized Ethanol of Black Soldier Fly (Hermetia illucens L.) Larvae Meal-Extract Yields and Characterization

Abstract

The objective of this research was to investigate and compare the results obtained in the intensification and integration of (sc-CO₂) under different pressure conditions (25 and 30 MPa) at 60 °C. When intensifying the process, ethanol (10%) was used as a co-solvent (sc-CO₂ + EtOH). In the process integration, black soldier fly larvae flour, defatted via supercritical extraction (SFE), was the raw material for pressurized liquid extraction (PLE) using ethanol as solvent. The extract yields, fatty acid profile, free fatty acids, triacylglycerols (TAGs), oxidative stability, and nutritional quality of the oil obtained using sc-CO₂ + EtOH were evaluated. The composition of bioactive compounds (carotenoids, acidity, antioxidant compounds, tocopherols, and phospholipids) was determined in both extracts. The yields of the extracts were different by 32.5 to 53.9%. In the extracts obtained with sc-CO₂ + EtOH (10%), the predominant fatty acids were oleic, palmitic, and linoleic, with considerable levels of desirable fatty acids (DFA), tocopherols, and phospholipids. The nutritional indices showed good values for polyunsaturated and saturated fatty acids (PUFAs/SFAs), above 0.45%. Extracts from larvae meal defatted with SFE showed carotenoids, phenolic compounds, and antioxidant activity. HPTLC and HPLC analyses indicated the presence of amino acids, sugars, phenolics, and organic acids in their composition. This study revealed that the supercritical fluid extraction (SFE) process, or its conditions, can modify the fatty acid composition and the presence of minor bioactive compounds in the obtained extracts.

Keywords: anthropoentomophagy; bioactive compounds; extraction processes; fatty acids; insect; sustainable extraction.

Figure 1

Integration of green extraction processes for obtaining purified extracts of black soldier fly larvae meal.

Figure 2

HPTLC plates; (A) indicates the presence of amino acids with Ninhydrin as a developer; (B) indicates the presence of sugars with development using Molish reagent; (C) indicates the presence of compounds with fluorescence at 366 nm with mobile phase ethanol/ammonium hydroxide/water (75.5:12.5:12).

Figure 3

Chromatogram of the ethanolic extract of defatted flour from black soldier fly larvae with some maximum absorption spectra (UHPLC, Thermo Scientific Ultimate 3000 RSLC analytic system) reading at 280 nm.

Figure 4

Chromatogram of standard compounds (galic and benzoic acids, purocatechol) with maximum absorption spectra (UHPLC, Thermo Scientific Ultimate 3000 RSLC analytic system) reading at 280 nm.