3.8 Fat and Protein in Various Edible Insect Species

TABLE 3.8 Fat and Protein in Various Edible Insect Species

Insect species Common name Life stage used Protein (% dry matter)

Fat (% dry matter)

Acheta domesticus house cricket Adult 60–75 7–20 Gryllodes sigillatus banded cricket Adult 60–75 7–20 Locusta migratoria migratory locust Adult 40–60 10–25 Hermetia illucens Black soldier fly larvae/pre-pupae 30–60 20–40 Tenebrio molitor Common mealworm larvae 45–60 25–35 Alphitobus diaperinus lesser mealworm larvae 45–60 25–30 Bombyx mori silkworm larvae/pupae 50–70 8–10 Sources: Original table for this publication, using values averaged from various sources, including Rumpold and Schluter 2013; Jensen et al. 2019; Beniers and Graham 2019; Irungu et al. 2018.

Researchers are continuously discovering other applications for insect protein. For example, in Korea, insect powder from mealworms (Tenebrio molitor) has been tested in hospitals as a protein supplement to help patients, especially elderly patients, recover from various maladies (see photo 3.1). As a result, Korea’s MAFRA actively supports developing insect-based foods for health purposes (see photo 3.1 for examples).

Insects are a source of essential nutrients. Insects provide fats and important micronutrients, especially iron and zinc, which are often deficient in foodinsecure populations (Black et al. 2013). Protein and fat contents vary among edible insect species depending on the insect’s type and development stage (Rumpold and Schluter 2013; Roos 2018). An insect’s fat content is specific to that insect’s stage of development (examples in table 3.8). These micronutrients are an important contribution to diets in Africa where these minerals are often deficient among children (Black et al. 2013; Holtz et al. 2015). Minerals from insects and animals are characterized by high iron bioavailability (Hallberg et al. 2003) and, therefore, are important in diets dominated by staple plant foods. Iron in edible insect species has been shown to be highly bioavailable in laboratory studies (Latunde-Dada, Yang, and Vera 2016). Consuming the exoskeletons of insects provides chitin, an indigestible fiber. Insect chitin may have probiotic properties that enhance healthy bacteria in digestive systems (Selenius et al. 2018; Stull et al. 2018). One study shows that adding 5 grams of dry insect protein per day to a person’s total nutrient intake could alleviate that person’s risk of nutritional deficiency of zinc, protein, folate, and vitamin B12 in Africa (Smith et al. 2021).

ASF are important for combatting undernutrition. ASF include all foods that derive from animals, including fish, meat, dairy, and even insects, among many more. In food-insecure situations, households prioritize carbohydrate-rich staple foods to avoid hunger and meet dietary energy needs (Fraval et al. 2019).

PHOTO 3.1 Insect-Based Health Supplements from the Republic of

Korea

A mealworm powder product. The label’s translation: “Recommended for convalescent patients. Insect processed food. Protein-rich powder” A mealworm oil capsule. The label’s translation: “100% Mealworm. Patent no. 1-1859174. Ministry of Agriculture, Food and Rural Affairs” A “white-spotted flower chafer beetle” powder. The label’s translation: “Fill the man’s pride”

Photographs © Nanna Roos / University of Copenhagen. Used with permission from Nanna Roos. Further permission required for reuse.

But studies show that consuming a diverse diet protects against malnutrition (Development Initiatives 2018). As such, even small amounts of ASF in the diet benefit the nutrition and development of the most vulnerable, particularly children (Skau et al. 2015; Dror and Allen 2011; Bhutta et al. 2008). ASF improve the quality of protein intake and enhance the bioavailability of critical micronutrients. Meat is an important ASF, but unlike insects, red and processed meat is associated with the increased risk of some noncommunicable diseases (Godfray et al. 2018). In high-income countries with industrialized food systems, 60 percent of the protein in diets derives from ASF, in contrast to 20 percent in diets in low-income African countries (IFPRI 2015).

The demand for animal feed has increased in Africa. The rising demand in Africa for meat from fish, poultry, and livestock stimulated the demand for animal feed by 30 percent from 2014 to 2019 (Vernooij and Veldkamp 2019). The demand for meat, milk, fish, and eggs is concentrated in the East and West African countries with the fastest economic growth (Robinson and Pozzi 2011). Kenya, for example, has seen a steep increase in demand for animal feed because of the country’s growing demand for animal meat. From 2008 to 2018, Kenya’s animal feed production increased from 375,000 to 900,000 tons (Vernooij and Veldkamp 2019).

In 2019, the EAT-Lancet Commission on Healthy Diets from Sustainable Food Systems developed global principles for healthy and sustainable diets (Willett et al. 2019). The Commission’s guidelines point at reducing highincome countries’ meat consumption. However, the Commission specifically recognized that combatting undernutrition in food-insecure African populations depends on increasing the intake of ASF. In this view, the emerging

opportunity to scale up insect farming to meet dietary needs and reduce undernutrition is promising. However, farming edible insects as an alternative to traditional livestock was not included in the global guidelines, which cited the lack of evidence and documentation on insects’ health impacts and the benefits of scaling production (Willett et al. 2019).

There is also limited but promising evidence that insects as livestock feed improve animal health and nutrition. The partial or complete replacement of soybean meal or fishmeal in animal feed with insects can provide valuable nutrients and compounds that improve animal microbiota and optimize animal health. While few studies have been conducted on the effects of insectderived compounds in animal feeding trials, initial investigations are showing great promise. Most of the trial studies that investigate insects as a feed source in animal diets focus on the animal’s growth performance, the health and microbiological implications for the animal, and the insect’s nutrient composition (Sogari et al. 2019).

Mealworms are a promising aquafeed ingredient. A study tested the effect of yellow mealworm larvae (Tenebrio molitor) protein on the growth performance of shrimp (Macrobrachium rosenbergii) over 10 weeks (Motte et al. 2019). The shrimp gained the most weight and had the best feed conversion ratio (FCR) when mealworm constituted 50 percent of the shrimp’s aquafeed. The study also showed that mealworm feed can be a competitive alternative to traditional aquafeeds (Feng et al. 2019). In another study investigating the digestibility of five different insect meals in Nile tilapia fingerlings, mealworm larvae meal showed the best digestibility, indicating a potential alternative feed for fingerlings (Fontes et al. 2019).

There are opportunities to replace fishmeal with BSFL meal. BSFL meal has been explored as a replacement for fishmeal in trout and salmon diets (Renna et al. 2017) and for African catfish soybean meal diets (Aniebo, Erondu, and Owen 2009). Generally, BSFL meal can replace other protein sources with no negative effects on the fish’s growth and survival rate. One study shows that replacing 10–30 percent of fishmeal with BSFL meal in rainbow trout diets modifies the trout’s gut microbiota, hence improving the trout’s gut health. Compared with fish fed only fishmeal, the insect-based diets induced higher bacterial diversity and more mycoplasma in the fish. These changes in microbiota are attributed to the prebiotic properties of the BSFL’s chitin (Terova et al. 2019). The only downside is that replacing fishmeal with BSFL meal reduces the fat quality of certain fish, like trout, because BSFL lacks the healthy longchained omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid). That said, feeding fish offal to BSFL improves BSFL’s fatty acid profile.

Insect meal can substitute for poultry feed ingredients. BSFL can replace fishmeal in chicken feed without any negative effects on the chicken’s growth performance (Awoniyi, Aletor, and Aina 2003). Other studies have shown that feeding laying hens BSFL meal did not change the hens’ feed intake, body weight, or laying performance (Heuel et al. 2019; Osongo et al. 2018). A metaanalysis of 41 scientific publications that studied the growth performance effects