Nutrient Composition and Growth of Yellow Mealworm (Tenebrio molitor) at Different Ages and Stages of the Life Cycle

Abstract

The nutrient composition of yellow mealworm (YM) Tenebrio molitor varies based on the stages of the life cycle, the rearing conditions, and the feeding substrate. This study monitored the growth of yellow mealworm larvae at 8, 10, and 12 weeks of age, separating samples into large-sized and small-sized insects. During the experiment, we measured the nutrient composition: dry matter (DM), crude protein (CP), crude fat (CF), crude fibre, chitin, crude ash, and nitrogen free extract (NFE) of YM at different age groups and sizes. We measured the nutrient composition of the pre-moult, moult, cuticle, and pupae as well. The results show that there is no significant difference between the compositions of the different age groups, but larger-sized individuals had a higher DM and crude fibre and lower chitin and NFE than the smaller sizes. The pre-moult and moult stages showed no significant difference in nutrient composition. Although the cuticle had a high DM (97.5%), that did not cause any significant difference between the DM of the moult and pre-moult, because it is only a negligible part of the total wet weight. With the increased DM, the crude protein content and the chitin content, fibre, ash content, and NFE increased, while the fat content decreased. The DM, CF, and chitin contents of pupae are significantly lower than those of the pre-moult and moult stages. Our results show that it is the size and not the age that has a positive effect on the nutrient composition of YM.

Impact of the Addition of Tenebrio molitor and Hermetia illucens on the Physicochemical and Sensory Quality of Cooked Meat Products

“…We used whole larvae, whereas many other authors used dried or otherwise heated insect larvae, which clearly has an impact on the proximate composition results of the insects [ 6 ]. Besides this, fat and protein concentration are also influenced by factors such as the species, age, or feeding of the insects [ 7 , 10 , 11 , 20 , 40 , 41 , 42 , 43 ]. Due to this, already published data on the protein and fat composition of H. illucens and T. molitor are quite variable.…”

“…Several publications presented only the nutrient composition related to the dry matter, e.g., [8][9][10][11]42,44,45]. Considering different publications that presented the protein and fat content of the whole insects and after recalculation of published data to the whole insect nutrient composition (considering dry matters for T. molitor of 37% to 39% and H. illucens of 28% to 33%), whole larvae of T. molitor consist of 16.6% to 20.5% protein and 8.2% to 14.1% fat [8,9,[40][41][42][43]46]. Whole larvae of H. illucens consist of 9.1% to 14.4% protein and 10.2% to 12.3% fat [10,11,29,44,45].…”

Acheta domesticus (house cricket) as human foods ‐ An approval of the European Commission ‐ A systematic review

“…(Aguilera et al., 2021; Azagoh et al., 2016; Baek et al., 2019; Kemsawasd et al., 2022; Kuntadi et al., 2018; Laroche et al., 2019; Meyer‐Rochow et al., 2021; Ordoñez‐Araque & Egas‐Montenegro, 2021; Toviho & Bársony, 2022; Zielińska et al., 2015)…”

Improving the nutritional values of yellow mealworm Tenebrio molitor (Coleoptera: Tenebrionidae) larvae as an animal feed ingredient: a review

“…The fat content of YML is relatively high (~ 22.3%–39.5% DM) compared to other protein sources commonly used in animal feed [ 5 , 24 – 27 ] (Table 3 ). The fatty acids profile of YML showed abundant unsaturated fatty acids (UFA) contents (21.9%–40% of total fatty acids content), whereas the contents of saturated fatty acid (SFA) is lower (22.7%–25.3% of total fatty acids content) [ 5 , 29 , 41 ] (Table 4 ).…”