字幕列表 影片播放 列印英文字幕 We need to talk about meat. Unless you’re a practicing vegan or vegetarian, you’re probably getting a large percentage of your protein from livestock like cows, pigs, and chickens. Now I’m not here to judge your eating habits. I’m addicted to the taste of flesh myself, but our meat-heavy diets are bad for the planet. Livestock raised for food makes up about 14-18% of our greenhouse gas emissions, and the land requirements to grow their food is responsible for about 80% of all deforestation in the Amazon. But there may be a way to have our beef-cake and eat it too, as researchers from Harvard just announced they’ve developed a technique that brings realistic lab-grown meat one step closer to the dinner table. The issue the team was trying to solve was how to grow skeletal muscle tissue in long thin fibers, like how it occurs naturally in livestock. If you’ve ever looked at the grain of a steak or at shredded pork or chicken, you’ve seen what I’m talking about. Mimicking that fiber structure has been a huge challenge for lab-grown meat. You can’t grow muscle cells like that in a petri dish all by themselves. They need something to hold on to as they grow. So the researchers set out to find a material they could use to grow their cells in 3D. The material had to be edible, something the cells could easily latch on to, and cheap enough to produce to keep costs down. The scientists settled on gelatin, and they spun it into fibers using a technique inspired by cotton-candy. The finished product is similar to the supportive extracellular matrix of natural muscle tissues. With their gelatin nanofibers spun, the researchers tried growing rabbit and cow muscle cells on them. While the finished products did not contain as many muscle fibers as natural meat, they did achieve a texture that was similar to the real thing. Now don’t go thinking lab-made beef is what’s for dinner. There are a number of other hurdles scientists need to clear before more sustainable and slaughter-free meat is on store shelves. For example, scientists will have to figure out how to grow cells without using animal serum, the most common being Fetal Bovine Serum, or FBS. FBS is harvested from the fetuses of slaughtered pregnant cows. It’s very expensive, and most lab-grown meat techniques rely on large quantities of it. So any product that relies on FBS isn’t helping much to cut down on greenhouse gasses, cost, or cruelty. There’s also the matter of taste. Meat is more than muscle; its flavor and juiciness also comes from fat. Growing fat cells in a lab that mesh with muscle and recreate the texture of steak has proven to be a challenge. And to get cells to reach maturity, we're searching for better sources of stem cells. But even if these technical hurdles are all solved, the finished product may be only slightly less damaging to the environment than raising livestock. Because of the energy lab-grown meat takes to manufacture, growing all our steaks and burgers in a dish may cut greenhouse gas emissions from beef by as little 7%, and actually produce about 4-5 times more greenhouse gasses than chicken or pork. So, lab-made meat is still a work in progress. And even if it’s eventually appetizing, cheap, and eco-friendly, it may still face challenges from the powerful livestock industries that have a beef with competition. They’re already pushing lawmakers to pass laws that forbid calling it “meat,” or they may come up with some other marketing campaign to turn public opinion against it. Then again, they may see the potential upsides of lab-grown meat, like some large meat processing companies have, and invest in projects developing alternative proteins. But even with money pouring into research and progress being made by scientists like the ones at Harvard, lab-made meat that’s tasty, slaughter-free and environmentally friendly is still a long ways away. Say they perfect lab-made meat and create a burger patty that was indistinguishable from ground beef. Would you eat it? Why or why not? Let us know in the comments. Make sure to subscribe to Seeker and thanks for watching.
B2 中高級 實驗室培養的肉類的這一突破可以讓它看起來像真正的肉一樣。 (This Breakthrough in Lab-Grown Meat Could Make it Look Like Real Flesh) 14 1 林宜悉 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字