Regarding the cities of the future, leaders in all walks of life may have different imaginations: driverless cars, artificial intelligence, virtual reality... But people are iron rice is steel, for the future, the majority of foodies may only care about one question: in the future city, what do we eat?
In 2050, there will be 9.8 billion people on the planet, about 68% of whom will live in cities. To ensure that the world's 9.8 billion people are fed, fed and not hungry, we need to increase the food production we already have by 70%.
At present, the world's agricultural land has reached 38% of the total land area and is basically saturated. In the future, the extreme climate brought about by climate change will bring greater uncertainty to the production and supply of food.
"Interstellar" has depicted such a scene - the deterioration of the earth's climate environment, crop blight and sandstorms, human beings forced to return to agricultural society, and fight the food crisis. If the climate catastrophe depicted in Interstellar does indeed come, is there any other way to get through it than to migrate to space like in science fiction?
Source: Interstellar
There's a possibility that we can get out of farmland and pasture and synthesize food in the lab. And, the future of creating delicious food in the lab, without having to look at God's eyes, may be closer than we think.
Meat, with the dual properties of nutrition and deliciousness, is the magical creation of nature.
A native chicken, starting from the shell, after several months of growth to achieve the ideal meat quality. It is definitely not easy to replicate the life crystals that have been bred in the laboratory for the past few months, so that the artificial chicken is close enough to the genuine in terms of nutritional value and taste.
Nutrient content is a relatively easy problem to solve. The main nutritional value of meat is protein, so the first step in making artificial meat must be to extract protein as a raw material. Protein has no more than two sources: plants and animals. Synthetic with plant protein is called plant meat, made with animal protein... Wait, it's not called animal meat, it's called cell meat! As for why, we'll elaborate on that in a moment.
Let's start with plant-based meat. Soybeans, peas, and wheat are all common sources of plant protein. The protein is extracted from these plants, and the main raw material is there. After a series of processes such as fermentation and extrusion, seasonings and pigments are added to simulate the taste and appearance of real meat, and it is completed. At present, we can buy a lot of plant meat products in China.
Grandpa's plant-based broiler fried chicken
Image source: Xinhuanet
Making meat from plants has long been a novelty. As early as the time of Emperor Wu of Liang, vegetarian chicken made of soy products was used instead of chicken in Jai cuisine. Obviously, however, plant-based meat looks and tastes more like meat than vegetarian chicken because of the deeper processing method.
Vegetarian chicken, it really doesn't look like meat
Image source: sohu
For example, instead of using soybeans directly, soy proteins are isolated separately, and then the proteins are pulled into silk, so that they are intertwined to form a network of fibers to simulate the texture of real meat. In order to restore the complex and beautiful taste of real meat, it is necessary to add a variety of auxiliary spices: coconut oil to reduce the fat aroma of meat, wheat to reduce the strong taste...
Pea steak, good realistic texture!
Image source: novameat
Plant meat is committed to making fake real, but in fact it is more controversial to do how real it can be. Many people think that the taste of plant meat is far from real meat: either it tastes like soybean after chewing for a long time, or it is almost as meaty.
Therefore, in order to make the plant meat more delicious, the merchant also wants to break the head, and may add a variety of flavoring agents. This actually leads to a problem -
Many people eat plant meat for health: compared with animal meat, plant meat should contain lower calories and saturated fatty acids, which is good for cardiovascular health. But additives added to reduce the meat flavor may offset these health advantages. For example, coconut oil, which is added to add oil aroma, contains 80% saturated fatty acids. In order to taste good, a lot of salt is usually added (high blood pressure warning!). ）。
Wake up, diners
Image source: FoodNEXT
Therefore, the current plant meat is facing a dilemma: if you want to pursue a taste closer to animal meat, it is necessary to add more oil and other condiments, which will bring some potential health hazards, if you want to pursue a healthier concept, then the taste will not meet the standards of many consumers. Coupled with the not-so-cheap price, plant-based meat still seems to be an "okay but not necessary" option for people.
"Beans are not meat!" Plant meat is the East Shi Gong! ”
In the face of such calls, scientists can't help but think: Using plants to fake is not a novelty, can we make real meat in the laboratory?
A piece of meat, fundamentally, is the many, many cells in an animal. We can raise a piece of bacteria from a petri dish in a biology class, so can scientists use a similar method to grow the cells that make up the steak?
Image source: unSplash
Growing animal cells is certainly much more complicated than raising bacteria with Petri dishes. In order for a cell to grow and multiply like in an animal, it is necessary to provide it with growth conditions that are similar enough to those in the body, including a variety of nutrients, temperature, humidity, pH, and so on.
Getting cells to multiply is only the first step. Just piling cells together can't make a piece of meat. A piece of lean meat, in biological terms, is a muscle tissue, made up of muscle cells arranged in a specific pattern, and they need structure.
Three different kinds of muscle tissue, muscle cells are arranged in different forms
Image source: wikipedia
And it's not just lean meat in steak! If you are an expert in steak tasting, you must know that the division of different parts of steak is very exquisite. There are lean and fat and tendons in a steak, and the proportion and distribution of fat and lean in different parts are different.
Who looks hungry?
So, making a piece of cellular flesh that is fake real must satisfy at least these two points:
1 Material: Cultivate a variety of cells so that they can form different tissues such as lean meat, fat meat and tendons;
2 Structure: Assemble the cells into tissues, and then combine the different tissues to assemble them into a piece of meat.
The problem of material can be solved with stem cells. Stem cells are the "source of all cells" in the biological body, and can differentiate into various types of cells.
Image source: Mustard SpeakeGreen
After the stem cells have been extracted from the cows, the next step is to put them on a "scaffold".
This bracket is made of edible materials using 3D printing technology. Scaffolds provide structural support to cells, guiding them to differentiate and arrange them the way we want them to. Just change the structure of the stand, and theoretically you can make all the types of steaks you like: filer, sirloin, rib eye... Even better, you may be able to choose the proportion and position of the fat and lean meat and tendons yourself, so that you can achieve the freedom of steak customization.
Cell culture ribs
Image source: Aleph Farms
At present, some companies have successfully cultivated a complete steak in the laboratory with such technology. In addition to beef, at the end of 2020, stem cell chicken nuggets produced by a start-up in the United States (70% of which are cultured chicken cells, while also adding plant protein) have received regulatory approval and can be sold in Singapore, which is also the world's first commercial cultured meat product, but stem cell meat is still a long way from being widely used worldwide.
So then again... Since it's all meat, why bother to put together a piece of cells from scratch?
First of all, the efficiency of growing cellular meat is much higher than that of farmed animals. A cow takes more than a year to be raised to produce a piece of cellular meat, and it only takes 2-8 weeks in the laboratory to grow a piece of cellular meat.
Fresh meat with all kinds of care
Source: Lychee News
And not just in terms of time efficiency, but also in resource efficiency. After the cattle eat the feed, only about 10% of the energy in the feed is stored in the meat, and the rest is consumed by breathing, eating, exercising and other processes. Growing cellular flesh avoids a large part of this depletion and improves energy utilization.
The environmental impact of cell-grown meat is also much lower than that of animal farming. 14.5% of global annual greenhouse gas emissions come from livestock – the largest of which is emitted from feed production processes, and... Cow burps and farts to excrete methane.
Hiccup~
Source: THECONVERSATION
As ruminants, cattle have a variety of microorganisms in their stomachs that help them convert the grass they eat into nutrients that are easily digested and absorbed. This conversion process produces a large amount of methane gas. While methane emissions don't seem to be as much, as a greenhouse gas, it's a full 25 times more powerful than carbon dioxide.
In addition to carbon emissions, the pollution caused by animal droppings is also staggering. The mainland's livestock industry produces 3.8 billion tons of manure every year, and if it is not handled well, the pollutants such as antibiotics and germs in the feces enter the water source and soil, which may cause environmental pollution and health risks.
With cell culture technology, it means we can eat delicious meat more environmentally friendly. Fish and bear paws!
The only thing that sounds sci-fi than growing a steak out of cells is synthetic starch technology, which became a hot topic last year.
Last year, researchers at the Tianjin Institute of Industrial Biology of the Chinese Academy of Sciences realized for the first time the synthesis of starch from carbon dioxide in the laboratory, which sounds as outrageous as making bread out of air.
But it doesn't seem so outrageous?
If you think about it, the grass at the doorstep of your home is converting carbon dioxide in the air into carbohydrates every day through photosynthesis.
Think of it this way, the process of synthetic starch is actually a large-scale reproduction of photosynthesis.
In photosynthesis, carbon dioxide and water are raw materials, sunlight is energy, and carbohydrates and oxygen are products.
In synthetic starch technology, the high concentration of carbon dioxide emitted by the factory is the raw material, the electricity and hydrogen energy converted from solar energy are energy sources, and the starch is the final product. Using electricity and hydrogen energy, the raw material can first be converted into simple hydrocarbons, such as methanol.
However, the biggest difficulty of synthetic starch technology is actually the next step: how to convert simple hydrocarbons like methanol into complex starch molecules.
amylose
methanol
Plant synthesis of starch requires more than 60 steps of reaction and transport between cells. The premise of these reactions is that there are various corresponding enzymes to catalyze them.
In the lab, researchers try to find a more streamlined path to get starch with fewer reactions. They first locked dozens of possible paths and then tried one by one.
In the process of practice, the various enzymes used often "fight", resulting in the final product being far from the ideal. Therefore, in order to make the product of the reaction completely controllable, it is necessary to adjust and test repeatedly.
In the end, the researchers simplified the reaction from carbon dioxide to starch to 11 steps. This means that we can synthesize starch with much more efficiency than plants – 8.5 times the rate at which corn synthesizes starch by photosynthesis. The annual yield of starch obtained by planting 5 acres of corn can be obtained in the laboratory with a bioreactor of 1 cubic meter.
Will patches of wheat field lose their jobs?
Image source: istock
In the future, when synthetic starch technology is fully industrialized, the exhaust gas of the factory may not need to be discharged into the air, but directly into the starch synthesis device, turning the waste gas into a resource - or an extremely productive resource.
However, between us and such a future, there is also a mountain called "cost". In order to reduce the cost of synthetic starch to the level of agricultural cultivation, it is necessary to at least increase the efficiency of electric energy utilization by several times and the rate of converting starch by dozens of times.
Of course, there is another question that we may be more concerned about - is synthetic starch good or not?
Rib noodles
Source: iStock
Although no one has tasted it yet, synthetic starch will at least not taste exactly like natural starch — because the only thing that can be synthesized in the laboratory is amylose, which is composed of amylose and amylopectin molecules. Due to the nature of amylose, noodles with synthetic starch may be stronger than ordinary noodles, but due to the lack of amylopectin, the noodles of synthetic starch will lack stickiness, and it is easy to paste after cooking for a long time.
So after solving the technical and cost problems, synthetic foods will face a similar problem: does plant-based meat eat like meat? Is Lanzhou ramen made of synthetic starch delicious? Is the boiled beef spelled out by cells the same taste as the boiled beef raised by eating grass?
Don't break the myth of boiled meat slices in my heart
Image source: iStock
The answers to these questions are more subjective and more individual than breaking through the technical and cost barriers. Maybe cell beef won't taste exactly like farmed beef, but that might just mean we need to treat cell beef as a new ingredient and create a new way of cooking that suits it.
In the future, when synthetic foods become more widespread, we will be able to make ingredients that are as similar to nature as possible with greater efficiency than nature and at a lower environmental cost. It may be difficult to replicate nature completely, but because of this, what kind of synthetic food culture will be bred by highly adaptable and creative humans is also worth looking forward to. *★
∧∨ flip up and down to see the reference content
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plant-based steak
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Audit: Deputy Chief Physician of Shanghai Municipal Center for Disease Control and Prevention Dr. Wang Zhengyuan of Nutrition
EDIT: rain
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Original title: Exhaust gas to noodles? Shiver, foodies of the future city
Source: Shanghai Science and Technology Museum
Edit: Garrett