Study On The Extraction, Composition And Refinement Of Chrysomya Megacephala Larval Oil

Larvae of Chrysomya megacephala, an important economic insect, are rich inhigh-quality oil. In this study, methods for oil extraction from C. megacephala larvaewere researched; oil content and fatty acid composition were compared among threedifferent dipterans, C. megacephala, Musca domestica L. and Hermetia illucens L..Process for refining oil from C. megacephala larvae was also preliminarilyinvestigated here.Crude oil was extracted from C. megacephala larvae using two different organicsolvent, anhydrous ethanol and petroleum ether. A higher oil yield was obtained withanhydrous ethanol. However, oil extracted using petroleum ether was clearer.Petroleum ether might have little influence upon the destruction of fatty acid by hightemperature due to its low polarity and boiling point, so it was more appropriate foroil extraction. Orthogonal experiments were carried out to optimize extractionconditions. The optimal condition was petroleum ether as the extraction solvent,temperature50℃, extraction time2.5hours, and solvent volume12ml/g. Under thiscondition, the rate of oil extraction from C. megacephala larvae reached83.90%.Oil content in larvae of C. megacephala (21.20%) was close to that of M.domestica (22.50%), but obviously lower than that of H. illucens (34.10%), revealingthat different feeds may affect the oil content of larvae from various species. Unsaturated fatty acid contents in larvae of C. megacephala and M. domestica were65.49%and59.59%, respectively, while that of H. illucens was only32.25%. C.megacephala larvae contained15kinds of fatty acids, including8saturated and7unsaturated ones. Unsaturated fatty acids predominately consisted of30.62%oleicacid,11.23%palmitoleic acid, and21.73%linoleic acid. H. illucens larvae contained7saturated and7unsaturated fatty acids. Unsaturated ones were primarily comprisedof18.36%oleic acid,19.16%palmitoleic acid, and18.96%linoleic acid. H. illucenslarvae contained5saturated and4unsaturated fatty acids. Saturated ones consisted of45.37%lauric acid,10.77%myristic acid, and10.54%palmitic acid; unsaturated oneswere comprised of12.78%obeic acid,12.08%linoleic acid, and6.94%palmitoleicacid.Oil of improved quality was produced after refining, including degumming,deacidifying and decoloring. However, meanwhile, the amount of refined oil wasreduced. Rates of recovery of oil were85%,53.55%, and27.85%, respectively, afterdegumming with water, deacidifying with alkali, and decoloring with adsorbent. Noobvious changes in oil iodine value and saponification valueoccurred after refinement,while oil color and acid value changed obviously. The quality of refined oil wasimproved, which appeared clear, transparent and close to colorless. With theexception of the iodine value, indicators of the refined oil met the first-gradestandards of industrial oil.