ACCORDING TO the United Nations (UN), human population is expected to exceed 9 billion by 2050. This means that the demand for food will increase dramatically over the coming decades whereas the Earth’s resources are limited. The way we currently feed ourselves, however, further decreases resources we can consume, thus making the situation even worse. As a solution to this problem, Food and Agriculture Organization of the United Nations (FAO) has been stressing the importance of “sustainable diets,” diets with low environmental impacts which contribute to food and nutrition security and to healthy life for present and future generations. Satisfying all these conditions, edible insects are emerging as an alternative food source. Let us find out why insects should be served at your next meal.
Nutritional values of edible insects
The nutritional values of edible insects are highly variable not only because of the wide variety of species but also because the values may differ depending on the metamorphic stage of the insect. In fact, large variation was found in the data when Rumpold and Schlüter (2013) compiled nutrient components of 236 edible insects. Yet, it was enough to prove that insects can be an important source of numerous essential nutrients; they provide sufficient amounts of protein, fulfill amino acid requirements for humans, are high in monounsaturated and/or polyunsaturated fatty acids, and are rich in micronutrients.
Because proteins are required for the structure, function, and regulation of the body’s cells, tissues, and organs, it is important to ingest the right amount of protein every day. People have mainly consumed meat and fish to satisfy adequate protein intake. However, this kind of diet turns out to be causing environmental harm as it results in reduced productivity of agricultural lands, pollution from fertilizers and pesticides, and climate change. In this situation, insects are regarded as an appropriate candidate for providing animal protein. For example, it has been proven by Lakemond in 2013 that mealworms and crickets have a protein content ranging from 19 to 22%, which is comparable to conventional meat products in terms of protein quantification.
Amino acids are very closely related to protein as they are the building blocks required for the biosynthesis of all proteins through human metabolism to ensure proper growth, development, and maintenance. While there are 20 proteinogenic amino acids, 8 of them – phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, leucine, and lysine – are classified as essential for humans. They must be attained from food as they cannot be synthesized in the human body. Among these, lysine is absolutely indispensable since it is not transaminated and its deamination is irreversible. Diets around the world are often low in lysine but fortunately, it can be obtained from some insect species. In the Democratic Republic of the Congo, for instance, lysine-rich caterpillars replenish lysine-poor staple proteins. Similarly, people in Papua New Guinea eat tubers that are poor in lysine but compensate for this nutritional gap by eating palm weevil larvae.
Edible insects are also a substantial source of fat. According to a research conducted by Womeni in 2009 to investigate the content and composition of oils extracted from several insects, their oils are rich in polyunsaturated fatty acids and usually contain α-linolenic acids (classified as omega-3 fatty acids) and linoleic (classified as omega-6 fatty acids), both of which cannot be synthesized by the human body. It has been proven by Michaelson in 2009 that these two essential fatty acids are crucial for nutrition as they seriously affect the development of children and infants. According to Naughton, a specific example of an edible insect with high fat content is Australia’s witchetty grub, a large, white, wood-eating larvae of several moths and beetles. Rich in oleic acid, it was the most important insect food of the desert and was a staple in the diets of Aboriginal women and children.
While micronutrients – including minerals and vitamin – play an important role in growth, immune function, and reproductive outcomes, micronutrient deficiencies are prevalent in many developing countries. Among these, iron deficiency has been marked as the world’s most common and widespread nutritional disorder by the World Health Organization (WHO). Thankfully, the intake of edible insects can improve iron status and help prevent anemia as a result. A table that compares the recommended dietary allowance (RDA) of minerals for a 25-year-old male with those supplied by the mopane caterpillar shows that the mopane caterpillar is an excellent source of iron; intake recommendation of iron for a 25-year-old male is 8mg per day whereas the Mopane caterpillar contains 31mg of iron per 100g dry weight. This figure is very high compared to beef, as it has an iron content of 6mg per 100g. In addition, most insects are generally believed to be good sources of zinc, which can lead to growth retardation, skin lesions, diarrhea, and impaired appetite if deficient. Again compared to beef, which contains an average of 12.5mg per 100g, palm weevil larvae, for instance, boasts a higher level of zinc as it contains 26.5mg per 100g.
Environmental values of edible insects
An increase in food production will be demanded in order to feed a growing world population. This will inevitably place a disproportionate burden on Earth’s ecosphere due to limited resources. If agriculture production continues in its present form, environmental problems such as increases in greenhouse gas (GHG) emissions, deforestation, and water pollution will be intensified. Thus, a dietary change is needed and insects can be an answer for this as well. There are a number of reasons why insect production is more sustainable than livestock production: more efficient feed conversion, potential to be grown on organic byproducts, lower emissions of GHGs and ammonia, and reduced water footprint.
When it comes to feed conversion, the need for grain and protein feeds rises in response to the increasing demand for meat. This is because far more plant protein is needed for the same amount of animal protein. Although feed-to-meat conversion rates vary depending on the class of the animal, the fact that insects require far less feed is obvious. According to Smil, 1kg of live animal weight in a typical U.S. production system requires the following amount of feed: 2.5kg for chicken, 5kg for pork and 10kg for beef. On the other hand, Collavo has found that the production of 1kg of live animal weight of crickets, for example, requires as little as 1.7kg of feed. Moreover, Nakagaki and DeFoliart estimated in 1991 that up to 80% of a cricket is edible and digestible compared with 55% for chicken and pigs and 40% for cattle. Thus, crickets are twice as efficient in converting feed to meat as chicken, at least four times more efficient than pigs, and 12 times more efficient than cattle.
Another advantage of edible insects is that they can be raised sustainably on organic side streams including bio-waste. Especially insect species such as the black soldier fly, the common housefly, and the yellow mealworm are drawing attention as they are very efficient at bio-converting organic waste; it has been proven by Veldkamp in 2012 that they can collectively convert 1.3 billion tons of bio-waste per year. Because of food and feed legislation, substituting high-quality feed with organic side streams is not permitted at present. However, once it is allowed, organic pollution will be greatly reduced.
With the exception of cockroaches, termites and scarab beetles, insects emit relatively few GHGs and relatively little ammonia in comparison with staple livestock. To be specific, according to Oonincx, edible insects such as mealworms, crickets, and locusts compare favorably to pigs and beef cattle in their GHG emissions and to pigs in ammonia emissions. Consuming insects is also environmentally-friendly in terms of water use. The term virtual water was first introduced by Chapagain and Hoekstra in 2003, which refers to the total amount of water used in the various steps of the production chain. It was estimated by Pimentel in 2004 that the production of 1kg of chicken requires 2,300 liters of virtual water, 1kg of pork requires 3,500 liters and 1kg of beef requires 22,000 liters. Even though concrete estimates of the volume of water needed to raise an equivalent weight of edible insects haven’t been provided, they are expected to be much lower; mealworms, for example, are more drought-resistant than cattle. Therefore, the act of consuming insects will likely prevent further threats on biodiversity, food production, and other vital human needs.
No longer disgusting
Despite the benefits listed above, consumer acceptance remains one of the largest barriers to the adoption of insects as an alternative food source. This is because people tend to imagine themselves swallowing the whole small, six-legged creatures upon talk of edible insects. However, in fact, insects can be processed and consumed in three different ways: as whole insects; in ground or paste form; and as an extract of protein, fat or chitin for fortifying food and feed products.
Insects, sometimes processed by roasting, frying or boiling, are often consumed whole in tropical countries. Yet, in most cases, it is difficult to notice whether a dish that contains insects really has insects in it. This is because they are usually ground into paste or powder and then added to low-protein foods to enrich their nutritional value. In Thailand and the Lao People’s Democratic Republic, chili paste with crushed and ground giant water bugs is sought-after as a main ingredient. The flavor of a giant water bug is even being reproduced artificially now. Another way of consuming insects is to extract the nutritional contents you need. Unfortunately, the cost of protein extraction is still prohibitive and more research needs to be conducted to render the process both profitable and applicable for commercial use.
Various attempts have been made to process edible insects into more palatable forms. As an affiliated restaurant with Korean Edible Insect Laboratory (KEIL) Corp., Papillion’s Kitchen provides dishes made of mealworm, crickets, grasshoppers, white-spotted flower chafer larvae and so on. Yet, the dishes – rice croquette, corn soup, cream pasta, chocolate chip, and so forth - do not look disgusting at all; they actually make your mouth water. In fact, Lee Jun-yeop (Researcher, Menu Development Team of KEIL) said, “Customers who have eaten dishes served in Papillion’s Kitchen show their surprise in that the taste of the dishes is not much different from food they usually have.” Lee also stated, “Those who had feelings of disgust in eating insects hesitated at first, but most of them responded positively after actually eating them.” He further added that people will soon be able to buy products that are currently available only at the restaurant also in nearby markets. Insects on your dish is no longer a story of a faraway future.
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It has been proven that eating insects is not only good for our health but also for the planet. Still, it cannot be denied that much more work needs to be done in order to fully realize the potential that insects offer for global food security. Nonetheless, insects make up the largest and most diverse group of organisms on Earth, giving them boundless potential to contribute to human well-being and sustainability.