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  • Nowadays, a lot of people are looking for ways to eat less meat and other animal products, because of either ethical or environmental concerns.

  • The good news is that there's a ton of plant-based alternatives, from just straight-up plants like chickpeas to products like tofu and seitan, also known as "wheat meat."

  • But, there may actually be a way to still get animal products without having to raise, and then butcher, animals.

  • Like, lab-grown meat, also known as "cultured meat" or "cellular agriculture."

  • With this technology, you can make things like protein mixes and chicken nuggets, and this isn't just a potential dream for the future.

  • Some of these are already hitting the shelves!

  • Firstly, let's talk about milk.

  • Now, there are already dairy alternatives, like soy milk, almond milk - There's every kind of milk now.

  • But they don't have some of the signature proteins found in real dairy.

  • Particularly, a macromolecule called casein makes up about 80 percent of the protein in milk, and whey, which is a mix of a couple of enzymes, makes up the other 20 percent.

  • But a couple of companies are now producing and/or selling what they're calling "animal-free dairy."

  • Instead of using cows, they use transgenic microbes, microorganisms with foreign genetic instructions to make proteins.

  • Scientists already know the amino acid sequence for the casein and a whey protein, so it's pretty easy to turn that into a genetic sequence and add it into a microbe like a yeast cell.

  • These microbes are then grown in a reactor, kind of like beer fermenting in a vat.

  • When the company's ready to make some milk, they filter the casein and whey proteins out of the brew, and then those are mixed with other ingredients, like fat and sugar.

  • What you end up with is something that apparently looks a great deal like the kind of milk you would get from a cow.

  • One company has already turned this into commercial products like ice cream.

  • And milk isn't the only product companies might be able to make this way.

  • Another company is using a similar process to make transgenic egg whites.

  • So, that's cool, but while those are definitely animal products, they are not meat.

  • Meat is, after all, not just protein.

  • It's, traditionally at least, actually part of an animal, largely the animal's muscles.

  • But there are a number of companies that are looking for ways to grow animal cells without needing the entire animal.

  • In fact, the first lab-grown meat has already hit the market in 2020.

  • Singapore approved the sale of lab-grown chicken.

  • To do this, scientists take stem cells from an animal, obtained by a small tissue sample.

  • Stem cells are a kind of cell that can turn into many different types of cells, including, for our purposes, muscle cells.

  • These cells are then allowed to grow in a solution of sugars, proteins, and other nutrients.

  • A kind of scaffolding made of proteins may also be used to help give the cells something to grow on.

  • When enough cells have been grown, they're harvested, and in the Singapore example, they have, so far, been turned into chicken nuggets.

  • Though you could conceivably turn it into other products as well.

  • The company, in that case, has said the process takes about 14 days.

  • The taste is apparently, drumroll please ... uh, like chicken.

  • Though the texture apparently doesn't quite match and is closer to firm tofu than chicken.

  • Texture, it turns out, is hard to pull off.

  • That's because meat also contains things like fat, connective tissue, and, like, capillaries and veins, but also, importantly, the muscle cells aren't just, like, a clump.

  • In real tissue, muscle cells are packed into long fibers - the "grain" of the meat.

  • This kind of structure is hard to mimic.

  • That's why a lot of the focus so far has been on things like ground meat, because the texture isn't quite as important.

  • But researchers have been making breakthroughs.

  • Playing around with different scaffolding designs, like long strings, has yielded some promising results.

  • And in early 2021, for example, a Japanese team announced that they had success with a method that combined both a place where the cells could grow and zapping them with electricity to make the muscle cells contract.

  • That combination made the individual cells actually come together into the proper muscle fibers that impart so much of the texture to meat.

  • They were using cow stem cells, and so they tested their results by cooking teeny-tiny steak strips.

  • That technique is still small-scale, and they're only one of many different groups working on this in different ways, but they think this technique could be a way forward.

  • These inventions mean that we may soon see animal-free "animal products" on our grocery shelves that provide us ways to eat less meat without eating less meat!

  • Thanks for watching this episode of SciShow!

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Nowadays, a lot of people are looking for ways to eat less meat and other animal products, because of either ethical or environmental concerns.


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Animal-Free Animal Products With Cellular Agriculture(Animal-Free Animal Products With Cellular Agriculture)

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    Julianne Sung 發佈於 2021 年 07 月 13 日