About Science
Lab-grown steak gets a little muscle
The alt-meat industry has created quite a sizzle, promising delicious burgers, steaks and even sushi that is grown from animal cells in the lab.
But most cellular agriculture still looks like mush. The manufacturing process — which starts with animal muscle and fat grown from stem cells in petri dishes — is fine for making burgers, but it fails to provide the kind of texture needed for more substantial cuts of meat, like steaks.
But scientists at Harvard University are reporting in a new study that they have found how to more closely mimic the form and flavor of real meat, by growing the muscle cells of cows and rabbits on a gelatin scaffold. Their research was published in the journal Science of Food.
To mimic this cellular environment, Kevin Kit Parker, a bioengineer at Harvard, and his colleagues decided to make scaffolds out of different concentrations of gelatin, a protein product derived from collagen. When collagen-rich meat cuts, such as beef chuck, are cooked, the heat naturally melts collagen fibers into softer gelatin, giving meat its succulent texture, Parker said.
To make gelatin microfibers, the researchers dissolved commercially available gelatin powder in water and spun it like cotton candy. Rotating the gelatinous slurry at high speeds allowed fibers to form at the bottom of the spinner. Using enzymes, the researchers then cross-linked the fibers to form a strong, woven structure for cells to grow on.
Rabbit and cow cells latched onto the gelatin scaffold, growing until they formed about a square inch of muscle.
To test whether the final product resembled the texture and behavior of meat that chefs and home cooks use every day, the researchers performed a variety of food industry analyses: simulating cooking by heating the labgrown meat on a hot plate, compressing it as if with a meat mallet and measuring the force needed to cut each piece of meat. They found that their lab-grown meat fell in between the springiness of a hamburger and a beef tenderloin. Knvul Sheikh
Ah, fall, time to sniff that pumpkin spice and … katsura?
Sugar, red and Japanese maples: You can drive up and down the East Coast to enjoy their fiery pyrotechnic shows each fall. Along the way, you may want to stop, take a deep breath and try to catch a whiff of the katsura tree’s sweet scent.
Autumn seems to belong to pumpkin spice, and odors are often overlooked when it comes to fall foliage. We rave about how leaves die colorful deaths and rarely discuss how their scent changes with old age. But right about now, the leaves of the katsura, found all over New York City and in many other parts of the United
States, are just beginning to turn.
the ia matter chemical that Autumn’s work decompose plant in of reaction in katsura the fungi and bacterose earthy scent is soil. But a leaves caramel conjures and burned sugar.. fall spice, As the leaves ignite, changing from plum purple or green to yellow, they abandon the haylike smell of leftover chlorophyll and adopt a scent more appropriate for a bakery.
a flavor A team researcher in Germad led by Ralf Berger, ny, collected and analyzed leaves from Katsura trees throughout the year, and found maltol, a chemical compound used in flavor
enhancers, perfume and incense. Joanna Klein
For some crabs in laboratory maze, right turns only
According to a new study, shore crabs can learn to navigate a lab-rat-style maze and remember it weeks later. While crabs that have never seen the maze before bump around aimlessly, experienced crabs race to the finish line with no wrong turns. The study, one of the few to look at whether crustaceans can perform such feats, suggests that crabs are quite capable of remembering routes.
Maze running could also be a way to measure the effects of changes in the sea, like ocean acidification and warming, on crabs’ cognitive abilities. Veronique Greenwood
How the butterfly discovered daylight
Once upon a time, perhaps some 300 million years ago, a tiny stream-dwelling insect akin to a caddis fly crawled from the water and began to live on mosses and other land plants. The creature would become the ancestor of the 160,000 species of moths and butterflies that populate Earth today.
A new study explains why nocturnal moths evolved into daytime butterflies. It wasn’t to avoid darkness-loving bats, as biologists once thought, but to enjoy an abundant new drink: the nectar of flowering plants.
The researchers reconstructed the ancient timeline using DNA sequences of contemporary moths and butterflies. They calculated that the ancestral moth emerged some 300 million years ago, at the end of the Carboniferous era, well before the oldest known moth fossil, which is only 200 million years old. Nicholas Wade
He sings very loudly, just not very well
The pressures of sexual selection have made peacocks gorgeous, wood thrushes sonorous and birds of paradise great dancers. The white bellbird has a different quality.
According to a new paper, this goofball boasts the loudest birdsong ever recorded. And he sings the most piercing note right into potential mates’ faces.
The white bellbird is a favorite among birders in Brazil. When several sing at once, they are “deafening,” and sound like “several blacksmiths trying to compete,” said Arthur Gomes, a student who contributed to the new research. Until a few years ago, assessing the amplitude, or loudness, of birdsong required an unusual amount of devotion and tech-savvy. But new tools are making the pursuit much easier. Cara Giaimo