Edible insects: a path towards more sustainable food systems?

By 2050: our planet will host 9 billion people. To meet the food and nutrition requirements the current food production system needs to alter its orientation and adopt more viable and sustainable options. At the same time, iron deficiency is the most prominent nutritional deficiency worldwide. Meat is generally a viable dietary iron source because of the high iron bioavailablity of heme iron, but increasing its consumption is not desirable if climate and nature conservation targets are to be met. Could insects play a role in providing dietary iron and assist towards transitioning to a lower population meat consumption?

Eating insects

Insect consumption as foods (entomophagy) is not a new concept in many parts of the world. It can offer significant opportunities to combine traditional knowledge and modern science in both developed and developing countries. Insects can be produced on food side streams using spent grains or bran and thus have a much lower environmental impact as conventional animal-based products. But whether insects can also serve as an adequate iron and zinc source for human diets has so far hardly been investigated. 30 g of dried insects contain as much iron as a 150 g steak or 30 g of dry beans: but how is iron from insects absorbed in humans?

‘’Our research aims to answer the question of whether edible insects can be
an adequate source of iron and zinc in the human diet’’, Niko says.

Rearing of Tenebrio molitor larvae in different substrates to evaluate growth performance (picture: Niko Hilaj).

Tenebrio molitor larvae production (picture: Niko Hilaj).

Breeding many insects

In collaboration with Wageningen University and Research, the research team of the Human Nutrition Laboratory at ETH Zurich became insect breeders. At the Ensectable AG production facility in Unterendingen (AG), the team accepted the challenge to breed Tenebrio molitor larvae (mealworms) aiming to identify the optimal growth conditions for increased iron and zinc concentrations and thus enhanced nutritional value. Dealing with thousands of beetles, laying eggs in our custom-made substrates to investigate the nutrient quality of grown-up larvae investigate was a once-in-a-lifetime experience. We had to solve several technical issues relating to the optimal rearing, such as providing optimal moisture in our substrates, while maintaining a low risk of mold growth. However, we could benefit of the large practical experience and insights of our rearing collaborator, Benjamin Steiner, a veterinarian who switched careers to become an insect breeder, and who is also member of the town council (Stadtrat) of Baden.

2 kg Tenebrio molitor or yellow mealworm beetles in one pot (Niko Hilaj).

Promising findings

The Human Nutrition Laboratory has large expertise of conducting human isotope studies. Thus, a series of clinical trials attempts to provide evidence on the true nutritional value of edible insects. Our current findings suggest that edible insects such as house crickets (Acheta domesticus) and yellow meelworms (Tenebrio molitor) are rich in iron and can be valuable dietary alternative source of moderately well absorbed iron - compared to well absorbed iron for planted based source foods.

The project is supported by the World Food System Center at ETH Zurich in collaboration with Coop, the Human Nutrition Laboratory at ETH Zürich and the Swiss Distance University of Applied Sciences (Fernfachhochschule Schweiz, FFHS). The rearing experiments were supported by World Food System Center fund.

ABOUT THE AUTHOR

Niko is a passionate PhD student at the Human Nutrition Laboratory at ETH Zurich in Switzerland. After completing his Food Technology master’s degree at WUR, he extended his industrial experience by focusing on process optimization and upscaling of novel iron-protein complexes for micronutrient fortification. Currently his research is focused on the bioavailability of iron and zinc from novel foods and food compounds. When Niko is not dreaming and experimenting, he likes being exposed to nature elements while riding his motorcycle.