Enrichment in specific fatty acids profile of Tenebrio molitor and Hermetia illucens larvae through feeding

Abstract

Tenebrio molitor (mealworms) and Hermetia illucens (Black soldier fly) larvae were analysed for the effect of feed composition on the fatty acid profiles. The larvae were raised on various feeds to which the basal diet had been supplemented to various levels with seed meals (flax seed, chia seed, hemp seed, and rapeseed). Fatty acid classes and composition of both insect larvae were similar in T. molitor and H. illucens larvae fat; however, the actual percentage composition differed; saturated (28.61% and 86.75%), monounsaturated (MUFA) (52.89% and 7.94%), and polyunsaturated (PUFA) fatty acids (18.49% and 5.31%). The supplementation of the basal diet resulted in larvae fat with increased omega-3 fatty acids levels, and subsequently a lower omega-6 to omega-3 ratio (T. molitor; 4.28:1 in the diet with 10% chia seed, H. illucens; 3.52:1 in the diet with 20% hemp seed) than those of the basal diets (50:1 and 9.91:1 in T. molitor and H. illucens respectively). In most of the larvae samples, the ratio achieved was closer to that recommended for a healthy diet.