By Kevin Bailey, PhD, Technical Analyst
Although the global production of food is sufficient to feed the current human population, the 2018 Global Report on Food Crises published by the World Food Programme estimated that 124 million people in 51 countries are currently facing acute food insecurity or worse.
These figures are an increase compared to the 108 million people reported in this situation in 2017. Although the rise was largely attributable to intensified conflict and insecurity in certain countries, persistent drought and poor harvests have also been a factor.
Too many cows?
Intensification of livestock farming cannot provide a solution, due to its considerable environmental impact. A report by the University of Oxford and Agroscope, an agricultural research institute in Switzerland, shows that meat and dairy products provide only 18% of total calories and 37% of protein in an average human diet, but account for 83% of arable land use and 60% of the greenhouse gases emitted by agricultural activities. To compound this, conversion of forest and woodland into grazing for cattle has also led to a loss of biomass biodiversity. However, simply removing meat from diets does not provide a complete solution, although this approach does considerably reduce the environmental impact of food production, amongst other benefits.
Plants under threat
Globally, wheat, corn and rice provide nearly 60% of total plant calories that humans consume, with the majority of the balance being provided by potatoes, soybeans, cassava, sorghum and legumes. Over recent decades, there has been a decline in genetic diversity within each crop and the number of species commonly grown. Consequently, Increased crop diversity has been a focussed area of research in tackling the issues of food security, reducing vulnerability to pathogenic or pest outbreak.
As the current human population of 7.6 billion is expected to reach 9.8 billion by 2050, greater stress will be applied on the livestock and agricultural industries to meet the demand of food availability for human consumption. As developing societies shift more towards a meat-based diet this increases the demand on global resources. Meeting this demand will be hampered by evolving environmental issues such as climate change, urbanisation and soil degradation, which will impact on the availability of arable land.
Consequently, there is a huge necessity to research into environmentally sustainable solutions to overcome the current and potential food availability shortfall.
Science to the rescue
One area of research that is becoming increasingly more prominent is that of the commercial production of cultured, or ‘clean’, meats in controlled laboratory environments. This process takes a cell from a living animal, usually either a stem, myoblast or myosatellite cell, and proliferates this with a protein in a suitable culture medium, usually consisting of a cocktail of glucose, amino acids and minerals, in a bio-reactor to provide oxygen to the growing cells.
Limitations with this technology are that the proteins shown to be most efficient for cell growth have been serum based and have been traditionally extremely expensive. For example, one litre of bovine serum used to cost up to £700, and 50 litres of serum may be required to grow enough tissue to produce a single burger! The first cultured meat burger, produced by the research team headed by Prof. Mark Post at Maastricht University, cost over £230,000 and took over 2 years to produce. However, continued research into new sera, cell lines and culture media has reduced this price around £8 a burger.
An animal-free alternative?
Crucially, to ensure that culture meat production on a commercial scale is viable and attractive, an animal-free alternative to serum is required to make ethical gains compared to traditional meat production practices. Current research is focussed on identifying which substances in blood are required for cell growth and potentially a solution may be found using algal or fungal extracts or the products of microbial fermentation, or using recombinant DNA technology to manufacture growth factors. In addition, further research needs to be undertaken to optimise the cell lines used, increasing the rate of cell proliferation and reducing the dependence on specific sera for growth. If this research is successful, in theory, it would be possible to continue to produce meat indefinitely without introducing new cells from a living organism.
Viable commercial cultured meat production will also require the development of edible, non-toxic-to-cells 3d scaffolds that can diffuse oxygen through the cells to support growth, otherwise the tissue grown will be flat or may be damaged on scaffold removal. Consequently, current cultured meat products in development are predominantly ground products, such as sausages, burgers and nuggets, as the tissue can be pelletised, which removes the need for a scaffold.
An uncertain future…
A key concern is that as the current cost of commercial cultured meat production is high, preservatives and fillers will be added to products to bulk them out, reducing their nutritional value. If this occurs, and more efficient non-animal derived protocol cannot be developed, it will be unlikely that commercial cultured meat production will be readily adopted by the public and act as viable alternative to the growing food crisis.
Photo credit to David Parry at culturedbeef.org