Lab-grown meats: How natural are they?

Industrial scaling of laboratory meat

Until today, most tissue engineering occurred in medicine, meaning that existing production processes and facilities are not designed for meat production. Any plan to commercialize cell-based meat must first solve these two following problems:

• How do we “feed” the cells?
• How do we grow them in large quantities?

One example would be that; to make this single hamburger, one would need to use most of his laboratory space to stack meat-cell culture trays in towers.

The difference between established bioprocesses and cultured meat bioprocessing is based on the complexity of the environment for both muscle-cell proliferation and differentiation.

The issue is that, to produce 1 kg of protein from such cells, we would need a 5000-liter bioreactor tank, which is not even proven for meat culture. So the main limitations in scaling up seem to be production costs and the lack of commercially available meat culture bioreactors.

Efficient culture media 

To mass produce lab meat, scientists must solve how to efficiently feed cells, since they require complex culture media.  The latter needs to contain sugars, salts, pH buffers, amino acids, micronutrients, and growth factor proteins.

The industry is considering growth medium recipes, since 80% of the final product’s cost is likely to be from culture media.

Of the aforementioned ingredients, growth factor proteins are the most difficult and expensive to obtain. These proteins are essential for cell proliferation and differentiation.

Most of the culture media used for meat production contain fetal bovine serum. This comes with a sense of irony. On one hand, the meat is not coming from slaughtered animals, but its essential nutrient, the serum, is. Alternative nutrients will have to be sought after, since serum-free media causes slower cell growth.

Another obstacle according to tissue engineer Torin Yeager at Finless Foods, is that growth factor proteins are not readily available to scientists or companies who want to mix barrels of media rather than liters. Getting them will be “an interesting design challenge,” agrees Jess Krieger, a researcher at Kent State University who studies meat tissue engineering.

What further complicates matters is the lack of a universal growing medium for all meat types.  Companies like Finless Foods are working on ways to feed the fish cells that will make up their bluefin tuna products.

Cells of different species, and even different cells within the same species, require different nutrient to thrive, says Yeager. While some components may be general to all animal cell species, up to half of the recipe may be different.

On the other hand, companies must also choose a cell line, which will initially come from an animal biopsy. The choice will be based on cells that multiply rapidly and have predictable performance , says GFI Senior Scientist Liz Specht.

Food safety of cultured meat

With regard to the safety of this new food, all aspects of the process should be considered:

Obtaining cells

The first step in producing a safe food product is to start with safe ingredients. In the traditional meat sector, we focus primarily on GMP (good manufacturing practice). In cultured meat, we focus on the source of the cells, which we have to watch closely. Van Eelen (2007) describes it as:

“These initial cells can be obtained from specially selected donor animals.”

Donor animals are kept under very strict environmental conditions, in other words, quarantined in clean rooms, with optimal feeding conditions, etc. Hygienic measures should resemble those of a laboratory setting rather than a farm’s, with specific pathogen free donor animals. Protocols should be provided to raise and keep these animals disease free, and they should be periodically tested for communicable diseases.

Sampling technique

All publications agree that samples should be taken with aseptic techniques (Vein, 2004), but the methods are rarely described. Of course, it depends on which tissue is used to collect stem cells. However, collection must be done through surgical procedures to avoid any contamination, as it is much more difficult to resolve it than preventing it.

Various procedures are described for handling the sample after it has been taken, such as rinsing the sample in ethanol solution (Benjaminson et al., 2000) or suspending it in a solution containing a combination of antibiotics (Verbruggen et al., 2017). So if antibiotics are used to keep samples free of contamination, we must ask ourselves:

Will they reach the final product?

Problems with culture media components

Some futuristic views propose that cultured meat could be healthier than natural ones, since we will have the possibility to influence their composition. On the other hand, the result of the changes in the environment for any objective must be closely monitored since cell motabolization can lead to the production of dangerous molecules.

All the components of the culture media must be safe to eat , as they could remain in the final product, in addition, some problems related to the components of the culture medium have been detected:

Fetal bovine serum:

With the use of this serum some technical difficulties arise, such as:

A high variability of the quality of the batch (Farzaneh et al., 2017) .

It may also contain viruses from fetal intrauterine contamination, such as BVDV .

These viruses can interfere with cell culture growth and / or be a food safety concern (Wessman and Levings, 1999) .

Antibiotics:

Broad spectrum antibiotics have been used in different publications (Freshney, 2016). If the use of antibiotics in cellular media for in vitro meat production becomes the norm, several problems could arise, namely:

It could increase antibiotic resistance, which is already a big issue (Ventola, 2015).

In short, antibiotics should not be present in the culture media, but will it be possible to grow meat without them?

Some researchers have found that not using antibiotics creates a loss of batches if contamination is present. It is difficult to determine the percentage of batches affected, but for example in the experiment carried out by Benjaminson et al. (2002) , 8% of the crops (48 in total) were contaminated and had to be discarded, so the loss of batches reduces efficiency and ultimately creates more waste of resources, which increases the ecological footprint of meat cultivated.

Cultured meat & the environment

The reduction in the production of greenhouse gases (GHG) has been proposed as one of the greatest potential advantages of farmed meat over conventional livestock production systems.   

In a work recently published in the journal Frontiers in Sustainable Food Systems (February 2019), greenhouse gases (GHG) from the production of beef cattle were compared with cultivated meat.

The preliminary conclusion of this study was that livestock systems are associated with the production of CO₂ and Nitrous Oxide, including significant emissions of CH₄, while emissions from cultivated meat are almost entirely CO₂ from power generation.

Under continued high global consumption, cultivated meat produces less warming initially than livestock. However, it has been noted that this gap is potentially narrowed in the long term. In some cases, livestock production caused much less warming, as CH₄ emissions don’t accumulate, unlike CO_2. In short, cultivated meat is not set to be too climatically superior to traditional livestock production.

Labeling related issues

Regulation (EU) 2015/2283, on novel foods states that when new foods are added to the EU list of authorized novel foods, there may be requirements regarding labeling, in order to fully inform the consumer in describing the food or clarify its composition.

In any case, the EU Regulation on Food Information for Consumers (also known as “the FIC Regulation”) will apply to in vitro meat once it is authorized, but its application can be difficult.

For example, there is an obligation to indicate on the label the name of the food, but there are unresolved problems regarding the name of in vitro meat, since this food is not yet on the market, there is no legal or common name. Many names already coexist (in vitro meat, cultured meat, clean meat, laboratory meat, etc.), and the choice of the name is quite delicate.

On the other hand, laboratory meat does not meet the current European definition of “meat”. According to the FIC Regulation, the definition of meat, for labeling purposes, is: “skeletal muscles of mammal and bird species recognized as fit for human consumption with included or adherent natural tissue (…)”.

In vitro meat does not consist of ‘skeletal muscles’, nor ‘naturally’ included or adherent tissues, which would mean that the term ‘meat’ could not be used in the current state of EU law. For the EU, probably only the submission of a new maintenance application to EFSA could start a process towards a regulatory framework.

Conclusions

According to the available information, cultured meat presents numerous advantages. However, apart from the great challenges encountered in the production process, there are still many challenges that we face in traditional production. The necessary commitments should be made for the following reasons:

With today’s large-scale processes, the challenge will be to achieve prices that match natural meat production.

It is not clear which cells are the best for cultured meat production, and neither is their source for that matter. Will laboratory animals always be needed as supply points? How “innocent” will the cell harvest be? It is clear that the animals will continue to be involved.

The ideal culture media often discussed in articles are without serum, antibiotics, and added hormones. It’s not clear how to achieve these goals, since most of the experiments described still employ them.

From a food safety perspective, risks may appear during production, so controls must be implemented for consumer safety.

One of the main arguments in promoting lab meat is its lower environmental impact. But as we have seen, it can lead to greater CO₂ accumulation on the long run_. Therefore, it may not be as advantageous as once thought. More studies will be needed when these products hit the market.

Laboratory meat does not meet the current European definition of “meat”, which would mean that the term ‘meat’ could not be labeled as such and difficulties are expected when applying the EU Regulation on food information for consumers.