Response Surface Optimization of Hexane Extraction and Chemical Characterization of Oil From Locusta migratoria

Abstract

Response surface methodology (RSM) was utilized to determine the effect of extraction temperature (25°C–50°C), extraction time (40–240 min), and solvent:solid ratio (6–20 mL/g) on oil yield from Locusta migratoria (LM) using hexane extraction. The optimum parameters obtained from response surface analysis were 30°C of extraction temperature, 80 min of extraction time, and 17:1 mL/g solvent:solid ratio. The highest oil yield obtained at optimum conditions was 50.33%. The fatty acid profile of extracted LM oil was primarily composed of oleic (36.82%), palmitic (23.88%), and linoleic (22.07%) acids. The oil principally covered triglycerides with equivalent carbon number (ECN) 48, 46, and 44, and the major triacylglycerols were palmitodiolein (14.97%), palmitooleolinolein (12.72%), and dipalmitoolein (11.79%). The sterol content of the LM oil was 12 638.66 mg/kg, and the main sterol was cholesterol, which covered 83.80% of the total sterols. The oil had a noticeable amount of γ-tocopherol (223.31 mg/kg), followed by α-tocopherol.

Practical Applications: Insects are encouraging candidates for incorporation in food systems due to their high nutritional value, low adverse environmental effect, and fast reproduction rate. Insect lipids have critical importance not only for being sustainable alternatives for plant- and animal-based oils; but also for enhancing consumer acceptance and industrial applicability. Moreover, oil extraction from insect matrix is essential before protein extraction. The findings of the current study show that hexane extraction is a convenient technique to obtain oil from Locusta migratoria, and the obtained oil is a valuable intermediate for food applications due to its considerable chemical composition.