Article by Lori Luo & Roberta Lock
Using Soy Protein to Grow Engineered Meat
Tom Ben-Arye et al., Shulamit Levenberg Lab
Behind every juicy steak you dig into is a whole supply chain focused on raising a cow. Animal agriculture has its own share of issues, needing large amounts of resources and space for the animals to flourish. Scientists are working on eliminating the animal altogether by growing meat in a lab. However, creating engineered meat isn’t as simple as placing cells in a petri dish. One of the biggest challenges is that cells need a nice environment suited to their needs to live and grow. In this study, researchers tested using soy protein to create a tasty and nutritious environment for the cells.
What did these researchers do?
Textured soy protein (TSP) is a byproduct of soy processing and notably has some key properties that make it a useful scaffold, such as high protein content and porosity. The researchers used TSP to create scaffolding and evaluated its ability to serve as an effective environment for bovine (cow) cells. They looked at a few important factors, such as how well TSP was able to support cell growth and if the cells were able to successfully distribute evenly throughout the scaffold. Once the cells attached, the researchers observed how the tissues developed, and noticed that there were higher levels of the proteins that cells make to improve their environment, showing that they were settling into the matrix. Most importantly, they evaluated how the tissues performed as meat, looking at their physical properties and taste after cooking it. Lucky for us, all volunteers reported a “pleasant meaty flavor”.
Muscle Formation in Textured Soy Protein Scaffolds
Why is this important?
Creating artificial meat allows us to solve many of the problems presented by traditional beef production. Lab grown meat lets us use less resources, like land and water, and contributes less greenhouse gasses to the environment. The use of a common food by-product provides an inexpensive, edible, and scalable method for housing cells for the development of a lab-grown meat. These successes in cell growth and development in this scaffold are additionally promising, as mimicking the natural environment cells grow in has long been a challenge for tissue engineers.
How did the researchers do this?
TSP scaffolds were generated using TSP flakes, which were sterilized and soaked in water overnight, then cut into cylinder shapes. Two types of TSP were observed: TSP-1, which contains 69% protein, and TSP-2, which contains 53% protein. To evaluate the properties of the scaffold, different mixtures of cell types that are native to cow muscle were added, namely pure bovine satellite cells (BSCs), co-culture of BSCs with bovine smooth muscle cells (BSMCs) or bovine endothelial cells (BECs), or a tri-culture of all three populations. These populations were chosen to model the complex cellular environment of the native tissue, which contains many different cell types.
What comes next?
TSP is a promising solution for scaffolding for engineered meat and could one day be used for mass production. However, there are still a lot of issues that need to be solved. Further study and evaluation needs to be done on TSP to ensure that it mimics the native connective tissue in muscle to ensure that the meat performs as expected during processing. Other similar materials should be explored as well, such as seitan, to provide more alternatives for consumers. Additionally, large scale culture of BSCs is difficult due to the time and resources it requires. Thus, methods of optimizing scale-up of cell culture and scaffold production need to be developed, and other types of cells that either contribute or lead to bovine muscle tissue should be explored as well. This work, however, shows important early steps towards lab grown meat. Maybe one day the steak on your plate will have been artificially grown with lab cultured cells and soy protein!