Researchers from Imperial College London have developed an innovative method for growing meat protein inside lettuce and tobacco plants, in an attempt to provide a sustainable alternative to traditional meat.
Although the idea may seem strange, it comes at a time when calls are mounting to reduce meat and dairy consumption for environmental reasons.
The research team focused on myoglobin, the iron-rich protein responsible for the red color and distinctive taste of meat. To achieve this, the researchers used a "gene cannon" technique, first cloning myoglobin genes from pigs and cattle, then blasting them into the chloroplasts (the organelles responsible for photosynthesis in plants) of tobacco and lettuce seedlings.
The team chose tobacco as an ideal laboratory model for developing the technology, while lettuce was selected because it is a food crop that could be used in the future to produce food ingredients. After these plants were grown to maturity, subsequent generations inherited the modified genes.
Measurements showed that myoglobin production was approximately 800 mg per kilogram of tobacco leaves and 810 mg per kilogram of lettuce leaves. By comparison, real meat contains between 8.1 and 11.2 mg of myoglobin per gram.
Although the concentration is lower in plants than in meat, researchers assert that plant-based agriculture is significantly more resource-efficient than livestock farming, as plant myoglobin can achieve protein productivity per hectare that rivals, and may even surpass, animal production, with much less water consumption and fewer greenhouse gas emissions.
Dr. Alexia Grove, a co-author of the study, said, "Plants can be engineered to produce animal-like myoglobin in their chloroplasts, providing a more sustainable way to produce an important component of plant-based meat products." She added that the protein can be extracted from the leaves, purified using industrial methods, and then added to plant-based meat products to improve their color, flavor, and nutritional value, as it is identical to animal myoglobin.
Currently, the most common method for producing artificial meat relies on microbial engineering, where animal proteins are inserted into the genome of bacteria or yeast. However, this new study offers a plant-based alternative that may be more appealing to consumers.
For his part, Professor Derek Stewart, co-director of the National Center for Alternative Proteins, described this achievement as "an exciting step forward," noting that the resulting protein was structurally sound (i.e., folded in the correct geometric shape that determines its function) and bound to heme (an iron-containing compound responsible for the red color in meat and oxygen transport), both of which are essential to giving the final product a color and flavor similar to real meat.
The team is currently planning to develop an industrial purification method, in preparation for using this technology in the large-scale production of plant-based meat ingredients in the future.
