[Smart Farmers] The Wandering Earth from an Agricultural Perspective: Asking Nature for Protein! Here Comes the "Doomsday Food" Survival List

Author: Zhang Wei (Associate Researcher, Chinese Academy of Forestry)

Recently, "The Wandering Earth 2" has been a hit. In the "doomsday" setting of the film, humans will choose to live underground or escape from the earth on a spaceship, but one of the key factors restricting human survival is food. Many science fiction movies have imagined the scene of food shortage when the doomsday comes. For example, the food earthworms in the movie "The Wandering Earth 1" are a good source of protein. In the movie "Snowpiercer", people living at the bottom can only survive by eating protein blocks, and these protein blocks are made of cockroaches.

(Stills from the movie "The Wandering Earth" are from the Internet)

The world population has reached 8 billion in 2022 and will peak at around 10.4 billion in 2080. The population growth rate far exceeds the rate of increase in food production. Therefore, producing more food in a limited space has become an important topic that scientists are constantly exploring. Under the "big food view", humans can get calories from plants, food from rivers, lakes and seas, and protein from microorganisms. Although the doomsday scenes assumed in science fiction movies are far-fetched, there are already many "doomsday foods" in real life that can provide high protein.

One of the main sources of "doomsday food" is insects, such as the cockroaches mentioned above, which belong to the family Cockroaches. The biomass of insects on Earth is more than 10 times the total amount of other organisms. The insect body has a high protein content and a full range of amino acids. It is a natural resource with great potential and can be renewed. There are about 1 million species of insects in the world, and at the beginning of the 21st century, there were more than 3,650 known edible insects.

In fact, in some areas of southern Africa, 2/3 of the animal protein consumed by residents comes from insects. In China, people in Tianjin like to eat locusts, people in Guangdong like to eat water lice and warty sandworms (commonly known as "grass worms"), people in Jiangsu, Zhejiang and Sichuan like to eat silkworm pupae, people in Fujian like to eat fried earthworms, people in the Northeast like to eat ants and fried beetles, people in Shandong like to eat cicada nymphs, and in recent years, cooking and eating yellow mealworms (commonly known as mealworms) has become popular.

From the perspective of the development of insect food abroad, Mexico is the world's hometown of insect food, where more than 370 kinds of insects can be eaten. In the "Insect Restaurant" in Paris, you can eat fried flies, ant lion heads, roasted cockroaches, steamed maggots, beetle pies, and more than 100 kinds of insect dishes made from butterfly, cicada, silkworm and other insect larvae or pupae. Nepalese people wrap live bee larvae with cloth and squeeze them, and fry the squeezed liquid like scrambled eggs. Thai people eat water bugs dug out from the ground with chili peppers, and salt ants are also a popular snack food in Thailand. Colombians do not eat melon seeds or peanuts in theaters, but eat fried ants. Cameroonians treat VIPs with a dish of palm maggots with salt, pepper and onions, put them in a coconut shell and cook them over a low fire, which is unique. The United States uses earthworm meat and beef to make hamburgers, and Japan uses earthworm powder to develop nutritional health products. Recently, Japan has launched a cricket food that not only takes into account deliciousness and nutrition, but is also durable in storage, adding a new type of doomsday food.

Insect food (picture from the Internet)

In addition to insect food, microalgae has great potential in solving world hunger and malnutrition problems and can be used as an alternative to "doomsday food". There are more than 72,500 species of algae living in freshwater and seawater worldwide. The larger ones are called macroalgae, which account for 20% of all species, and the remaining 80% are composed of microalgae. Microalgae are rich in protein, antioxidants, plant vitamins, omega-3 fatty acids and other minerals. Compared with other crops, algae cultivation consumes less soil and the amount of water required for cultivation can be reduced by 90%; it also contains higher protein.

According to relevant research, the protein yield of microalgae is 4-15 tons per hectare per year, which is much higher than the protein yield of wheat and beans, which is 0.6-1.2 tons per hectare per year. However, microalgae usually have a "grassy" and fishy smell, which limits their use in the market. Currently, an algae company in the UK has developed an innovative technology to solve the above problems, reducing the chlorophyll content of microalgae and reducing its "grassy taste" while retaining natural nutrients. In the future, it is expected to produce more nutritious and better-tasting vegan microalgae foods.

Microalgae food cultivation (picture from the Internet)

In the future, in addition to naturally grown animal and plant foods such as insects and microalgae, "artificial meat" will be a rare "doomsday food". The "artificial meat" here is not the soy products made from soy protein that simulate the shape, color and taste of meat that are currently sold in supermarkets, but animal meat artificially cultivated in the laboratory using animal stem cells, sugar, amino acids, oils and a variety of nutrients.

Science fiction writer Lassie proposed the concept of "artificial meat" in 1897. In his novel "A Tale of Two Stars", he pointed out that "artificial meat" is one of the synthetic foods introduced by Martians from Earth. The first "edible" artificial meat appeared in 2000, when a biological science research consortium supported by Touro University in the United States cultivated artificial fish meat using goldfish cells. In August 2013, the world's first artificial beef burger came out and a tasting event was held in London. On August 27, 2019, KFC and artificial meat company Beyond Meat cooperated to launch the first artificial chicken product. In the foreseeable future, "artificial meat" will not only be as delicious as natural meat, but will also be superior to natural meat in nutrition, production efficiency, and environmental friendliness, thus bringing new ways to solve production pressures, the environment, and animal protection caused by population growth and meat shortages.