Extracts from the edible insects Acheta domesticus and Tenebrio molitor with improved fatty acid profile due to ultrasound assisted or pressurized liquid extraction

Abstract

Extracts from the edible insects Acheta domesticus and Tenebrio molitor were obtained by ultrasound-assisted extraction (UAE) and pressurized-liquid extraction (PLE) using ethanol (E) or ethanol:water (E:W). Extraction yield, fatty acid profile, nutritional impact and cholesterol content were determined and compared with the initial insects. The highest extraction yield corresponded to PLE-T. molitor extracts. A decrease in total saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) contents, and an increase in the total polyunsaturated fatty acid (PUFA) content were observed for both UAE-E:W insect extracts, due to an enrichment in linoleic acid. The lipid indices (PUFA/SFA ratio, atherogenic and thrombogenic indices) for both UAE-E:W extracts were significantly improved compared with the initial insects. Although either extraction procedure led to cholesterol enrichment, the UAE-E:W conditions favoured the lowest concentration. Therefore, insects extracts with improved fatty acid profile can be selectively obtained, being UAE-E:W conditions preferred from the nutritional point of view.

Keywords: Acheta domesticus; Cholesterol; Edible insects; Fatty acids; Pressurized liquid extraction; Tenebrio molitor; Ultrasound assisted extraction.