Fatty Acid Profiles of Extracted Black Soldier Fly Larvae (Hermetia Illucens) Lipid Either Enriched Into Saturated and Unsaturated Fatty Acids Fractions as Feed Additive

Abstract

Black soldier fly larvae fat (BSFL fat) derived from Hermetia illucens has gained considerable attention as an alternative lipid source due to its distinctive fatty acid composition, particularly its high proportion of medium-chain saturated fatty acids. However, crude BSFL fat contains a heterogeneous mixture of fatty acids with different saturation levels, which may limit its application when a more defined lipid profile is required. This study aimed to fractionate BSFL fat into Extracted FFA, Enriched SFA, and Enriched UFA fractions and to characterize the fatty acid profile of each fraction using gas chromatography-mass spectrometry (GC-MS). Chemical hydrolysis using potassium hydroxide in an ethanol–water system, followed by acidification with hydrochloric acid, produced the Extracted FFA fraction. The FFA fraction was then dissolved in n-hexane and subjected to winterization at −30°C for 48 h to separate the solid Enriched SFA fraction from the liquid Enriched UFA fraction. GC-MS analysis confirmed that chemical hydrolysis produced an FFA fraction with a fatty acid profile nearly identical to crude BSFL fat, indicating that hydrolysis mainly changed the lipid form without altering the relative fatty acid distribution. Winterization produced two contrasting fractions: the Enriched SFA fraction was dominated by lauric acid (C12:0, 46.10%), myristic acid (C14:0, 20.19%), and palmitic acid (C16:0, 16.91%), with a total SFA proportion of 86.70%. The Enriched UFA fraction, in contrast, contained the highest total UFA proportion (62.50%), driven by markedly elevated oleic acid (C18:1n-9, 47.24%) and linoleic acid (C18:2n-6, 11.66%). These findings demonstrate that chemical hydrolysis combined with winterization is a simple and practical approach to obtain BSFL fat fractions with targeted saturation characteristics, providing a compositional basis for future lipid-based applications in animal nutrition and feed technology.