Don’t be scared by them when you visit the night market on National Day…

During the National Day holiday, no matter which city you go to, the night market will always be a popular place to check in. When the whole street is shrouded in the atmosphere of human life, you may inadvertently discover many alternative foods, such as insects.

Fried locusts, fried silkworm pupae, roasted crickets... Can these things be eaten? Are they delicious? How should they be eaten?

What are edible insects?

The so-called "bugs" in a narrow sense refer to insects, that is, animals of the class Insecta of the phylum Arthropoda. The adults of this group of little guys mostly have six legs, wings on their backs, and a hard shell (exoskeleton) covering their bodies. The development from egg to adult is metamorphosis, such as the development process of egg, larva, pupa, adult or egg, nymph (or larva), adult. However, in the eyes of the public, spiders, centipedes, etc. can also be considered bugs.

Cicadas do not have a pupal stage in their development, but instead molt directly from nymphs into adults. Source: Wikipedia

Dutch entomologist Ide Junghema has compiled a list of all edible insects known to humans. Roughly speaking, there are 130 countries in the world that have the habit of eating insects, and there are 2,111 edible insect species.

Edible insects, data source: List of edible insects of the world my country's food culture has a long history, and it is no less advanced in this regard. For example, according to the "Book of Rites", the royal family and nobles of the Zhou Dynasty liked to eat sauce made from termites, and even used them as sacrifices to worship their ancestors. The "Compendium of Materia Medica" of the Ming Dynasty recorded 76 species of edible and medicinal insects.

The most common edible insects, source: The contribution of insects to food security, livelihoods and the environment Halloran

In some areas, insects are even star products. For example, the sweet-scented osmanthus cicada (water beetle) in Guangdong and the ant eggs (a mixture of yellow ant eggs, larvae and pupae) in Yunnan would not be taken out unless they met distinguished guests.

How's the taste and nutrition?

As the saying goes, "It's hard to please everyone." Everyone has different taste preferences. Some say cicada nymphs taste like nuts, while others describe roasted crickets as dried shrimp or fried anchovies. However, there is relatively clear research on the nutritional value of insects.

Insects have two distinct advantages over conventional nutrition.

First, protein. The "Dietary Reference Intake of Nutrients for Chinese Residents" recommends that men aged 18 to 55 consume 65 grams of protein per day, and women consume 55 grams of protein per day. Children, pregnant women, and the elderly can adjust as appropriate; in addition, it should include nine kinds of amino acids that cannot be synthesized by the human body.

Essential amino acids, of which histidine is the ninth essential amino acid, Source: homemade by the author

Insects excel in both aspects. A study published in LWT-FOOD SCIENCE AND TECHNOLOGY in 2021 showed that 100 grams of locust powder contains 70 grams of protein, about 3.5 times that of lean pork; it not only contains a full range of essential amino acids, but also exceeds the recommended dose for 8 of them.

The second is fatty acids. The "Chinese Dietary Guidelines" believe that modern people eat too much livestock meat. There is a lot of saturated fatty acids in livestock meat. Long-term and large-scale consumption may cause diseases such as diabetes. Therefore, the "Chinese Type 2 Diabetes Prevention and Treatment Guidelines" recommends that daily intake of saturated fatty acids should not exceed 30% of total fatty acids.

The conventional approach is to eat more fish. In fact, insects are also a good choice. The fatty acid content of insects depends on the species and development stage, but generally speaking, unsaturated fatty acids are more abundant. For example, the unsaturated fatty acid content of adult cotton locusts is more than 2.5 times that of saturated fatty acids.

In addition, insects contain a special substance called chitin. Chitin is also called chitin, which is essentially a polysaccharide. It is found in the shells of shrimps and crabs, the exoskeletons of insects, and the cell walls of fungi. Humans cannot digest chitin because they lack specific enzymes.

Chitin in leafhopper wings, source: Wikipedia

However, being indigestible does not mean it is useless. Sustainable Agriculture Reviews 36, published in 2020, pointed out that chitin can play a similar role to dietary fiber, increasing satiety, lowering postprandial blood sugar, increasing stool volume, and reducing the probability of constipation. Furthermore, chitin can bind to lipid molecules. In 2023, a study published in Nature magazine mentioned that in animal experiments, chitin improved lipid metabolism and had certain benefits in reducing obesity.

What should I pay attention to when eating?

When it comes to "eating", safety is the most important thing. According to the source, the risks of eating insects can be divided into two categories.

One type can be solved on the supply side.

Insects and humans have very different physiology, so generally there is no need to worry about zoonotic diseases such as avian influenza and swine fever. However, there are always exceptions. For example, insects may be contaminated by pesticides, heavy metals, and mycotoxins when they eat food containing these harmful substances.

For example, a study by Chen Tong and other domestic scholars showed that the digestive tract and some glands of mealworms secrete a small amount of toxins, which may cause damage to liver tissue and must be properly removed during processing. In 2006, a survey by the Chinese Journal of Food Hygiene showed that the E. coli contained in some insects exceeded the provisions of laws and regulations. A study by the European Food Safety Authority in 2015 showed that these problems can be solved by improving the breeding and processing conditions of insects.

Mealworm larvae, source: Wikipedia

Another type of problem is more special and is related to consumers.

For example, some consumers may experience acute allergies after eating insects. In addition, gout patients need to limit their intake of purines. Currently, there is relatively little research on the purine content of insects, so it may be safer to avoid them.

So, how can we eat insects safely?

(1) Choose a reliable seller. The seller should have complete licenses, a clean environment, and the products should come from farmed animals rather than wild ones.

(2) Be careful to prevent allergies. Have you ever had food allergies in the past? If so, it is best to be cautious when trying unfamiliar foods. People who have no history of allergies can start by trying "common insects", such as silkworm pupae, locusts, cicada nymphs, and crickets.

(3) Try to choose a safe processing method.

"No matter how small a grasshopper is, it's still meat." For meat, thorough cooking is the most important cooking principle. In 2019, a review published in Food Control stated that processing methods such as boiling, frying, and roasting can improve the safety of edible insects.

Conclusion

In recent years, many scholars have said that replacing some meat with insects can alleviate the food crisis and reduce environmental pressure. For ordinary consumers, insects can expand their diet if they are willing to try.

As the "Dietary Guidelines for Chinese Residents" states, food diversity is an important guarantee for health.

Food variety, source: homemade by the author

Author: Zhao Yanchang, member of China Science Writers Association

Reviewer : Ran Hao, Distinguished Researcher, Key Laboratory of Ecology and Environmental Protection of Rare and Endangered Animals and Plants, Ministry of Education (Guangxi Normal University)

Produced by: Science Popularization China

References

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