Bowls of decidedly pink-tinged rice are about to feature on sustainable food menus, according to researchers who created rice grains with beef and cow fat cells grown inside them.
Scientists made the experimental food by covering traditional rice grains in fish gelatin and seeding them with skeletal muscle and fat stem cells which were then grown in the laboratory.
After culturing the muscle, fat and gelatin-smothered rice for nine to 11 days, the grains contained meat and fat throughout, resulting in an end product the researchers believe could become a nutritious and flavourful food.
Prof Jinkee Hong, who led the work at Yonsei University in South Korea, cooked and tasted the beef-cultured rice, which he hopes will be a more affordable source of protein than traditional beef, with a much smaller carbon footprint.
“When cooked, the rice retains its traditional appearance but carries a unique blend of aromas, including a slight nuttiness and umami which are characteristic of meat,” Hong said.
“While it does not exactly replicate the taste of beef, it offers a pleasant and novel flavour experience,” he added. “We tried it with various accompaniments and it pairs well with a range of dishes.”
Rice is predominantly a carbohydrate with smaller proportions of protein, fat, vitamins and minerals, the scientists write in the journal Matter. Integrating animal cells into rice makes it “possible to ensure a sufficient food supply”, they note, by creating “a new complete meal”.
The hybrid rice is more brittle than soft and sticky traditional rice, but it contained 8% more protein and 7% more fat. Rice with more muscle cells had a beef and almond-like odour, while rice with more animal fat smelled more of cream, butter and coconut oil.
According to the scientists’ calculations, hybrid rice could make food production more sustainable. Producing 100g of beef protein releases nearly 50kg of carbon dioxide, they write, while 100g of protein from hybrid rice would release less than 6.27kg of the gas. Hybrid rice should also be more affordable, they add, costing about $2.23 (£1.80) per kg compared with $14.88 (£12) per kg for beef.
Beyond making food more sustainable and affordable, the researchers believe hybrid rice could improve emergency food supplies to regions facing famine and serve as rations for astronauts and the military.
For the first experimental batches of hybrid rice, the researchers took muscle and fat cells from hanwoo cattle slaughtered at the local abattoir. But the team is exploring sustainable supplies of cells that can be maintained in the lab without needing more animals. Future versions of the rice could contain other types of meat or fish to cater for different tastes and nutritional requirements, Hong said.
The work received a mixed reception from independent experts. Prof Hanna Tuomisto, who researches sustainable food systems at the University of Helsinki, doubted that the rice would have a major impact. The end product contained 4.8g of cultivated beef cells per kg of rice, she said, meaning only 0.5% was meat and 99.5% rice. “The product is still basically rice and would be used to replace rice or other carbohydrate sources in a meal,” she said. “For replacing meat, the percentage of the protein in the final product would need to be higher.”
But Neil Ward, a professor in rural and regional development at the University of East Anglia, said hybrid rice raised the prospect of providing animal nutrients with greenhouse gas emissions that were eight times lower and at less than one-sixth of the cost. “This line of research holds promise for the development of healthier and more climate-friendly diets in future,” he said.
