Linseed to Increase N-3 Fatty Acids in Tenebrio Molitor (Coleoptera Tenebrionidae)

Abstract

to increase n-3 fatty acids in Tenebrio molitor (Coleoptera Tenebrionidae).The yellow mealworm Tenebrio molitor is one of the most promising edible insect species for human consumption and its potential use as a supplement of unsaturated fatty acids (UFA) for human diet, has been recently confirmed.The possibility to enhance polyunsaturated acids (PUFA), especially omega-3 (n-3) content, was evaluated in T. molitor mealworms. The purpose was to obtain an n-6/n-3 ratio more suitable for human consumption, which is useful for the secondary prevention of cardiovascular diseases. To this end, tests were carried out by adding linseed, as source of n-3 acid, to insect feeding diets. A decrease of saturated fatty acids (SFA) and an increase of PUFA contents, especially n-3 acid, was simultaneously observed in larvae fed on almost all the diets enriched with linseed. As a result, supplementation of feeding diets with linseed determined a favorable insect growth rate and a decrease of n-6/n-3 ratio to values more suitable for the prevention and treatment of cardiovascular diseases.

Influence of Different Diets on Growth and Nutritional Composition of Yellow Mealworm

“…The highest fraction of SFA is composed of palmitic acid, as its share ranged from 12.80 to 17.81% TFA for larvae grown on WB/RC and RB 100 diets, respectively. The same levels are reported in the literature [25,26,33,49]. Insect fats are valuable in terms of unsaturated fatty acids (UFA).…”

“…An important share (17% TFA) of α-linolenic acid (C18:3) has been found in the fat of larvae fed with WB/FC compared to the values found in other samples, where it ranged from 1.11 to 2.60% TFA for RB 100 and WB/RC, respectively. The enrichment of diets with flax flour increased also the α-linolenic acid share in mealworm fat in another research [46,49].…”

“…The high share of α-linolenic acid that is an ω-3, considerably reduced the ω-6/ω-3 ratio to 1.71 and increased the PUFA/SFA ratio to 2.79 in larvae bred on WB/FC. The insects diets enriched with flaxseed oil (up to 4%) or flax flour (10%) [51] significantly reduced the ω-6/ω-3 ratio, a result observed in mealworm larvae, as well as other insects [37,49]. The ω-6/ω-3 ratio reported elsewhere (15.90-21.03) [33] is comparable with the ratio (11.44 to 25.99) found in the present study for all the diets, excluding WB/FC.…”

“…The highest share of MUFA was found in mealworms fed with the RB 100 diet (49.35% TFA), and the highest share of PUFA was found in fat from larvae fed on WB/FC (46.63% TFA) and WB/SMc (41.15% TFA). Flax and S. marianum oil are known for their high content of PUFA, which resulted in the highest content of these fatty acids in the mealworm larvae [37,49,52,53].…”

The effects of the particle size of four different feeds on the larval growth of Tenebrio molitor (Coleoptera: Tenebrionidae)

“…Moreover, Dreassi et al (2017 evaluate the fatty acids requirements of mealworms by rearing them on diets with different fat contents. Francardi et al (2017) also studied the fat requirements and the composition of mealworm larvae reared on enriched diets.…”