Give peas a chance

When the sun comes out, Germans and Australians have something in common: we light a fire and start cooking food outdoors. The usual barbecued suspects are sausages of questionable origin, something sitting in a red marinade, and charred but somehow-still-raw chicken breast. While this does sound mouthwatering, a new trend might bring a fresh player to the barbecues and kitchens around the world – plant based protein products.

Let’s have a look at what makes plant protein special.

Plant based protein is not a complete newcomer. It’s no secret that soy and pulses (peas, lentils and the like) are high in protein. Tofu, a soy based protein-rich food, has been around for hundreds of years. You might love it or hate it, depending on whether you ate it in an Asian restaurant… or on meat-free Monday at the work mess hall.

Until now, the caveat of eating plant based protein (apart from tofu) is that they always come with baggage: starchy and non-starchy carbohydrates (think fibres) define the texture, taste and mouthfeel of pulse-derived products . Plus, they have an olfactory impact on digestion, which is fancy speak for ‘they make you fart a lot’. That’s where the new era of plant protein is different: it’s products that are just protein.

What exactly is this plant protein?

The main protein in soybeans, and in pulses, are globulins. These storage proteins are sources of nitrogen, sulfur and carbon during the plant’s germination. These molecules form the most important building blocks of everything else in the cell, required for making new protein, DNA and membranes, to name a few.

To keep the storage proteins out of the way of other cellular processes, they accumulate in protein bodies, small masses of protein enclosed by a membrane. During early growth, the nutrients are quickly mobilised to keep the plantling alive until its roots are developed enough to take up nutrients from the soil.

How to turn plant protein into food

While soy protein ruled the market for a long time, pea protein recently entered the spotlight. The famous and super-hip “Beyond Meat” burger consists largely of pea protein. However, if you think of mushy peas, it doesn’t really resemble meat in shape or taste. So how do you get from a pea to something that’s bound to replace meat?

Globulins are not very soluble in water on their own. If you drop the pH however – through the addition of acids – the protein can be solubilised. It’s not unlike raising the temperature of water to dissolve sugar: it takes certain physical conditions to turn a solid into a solution.

Once the globulins and other plant proteins are in solution, they can be separated from the starchy and non-starchy carbohydrates. In a process called ultrafiltration – think a coffee filter but a lot finer and with added pressure – the protein fraction is separated from the rest. This raises the protein content from around 20% in peas to over 80% in pea protein concentrates.

no animals were harmed in the making of this burger.

Now is the time for ingenious food processing: several different approaches turn the protein concentrate into something that has the texture, cooking behaviour and taste of meat. Hot extruders press the protein mass into shape, spindles rotate and create long fibres of protein, and seasoning, colouring and shaping does the rest of the work of creating convincing meat-like burgers or filets. Without advanced food chemistry, these meat alternatives could not exist.

And the ingenuity goes on: through enzymatic reactions, properties of the pea protein concentrate such as emulsification and gel strength can be optimised. Through these treatment, pea protein extracts can also replace egg white as a binding agent.

A justified effort

There are very good reasons to go through all the trouble of isolating, extruding, shaping and seasoning pea protein instead of just cutting up a cow or whatever is in a sausage (my guess is roadkill leftovers). Apart from the question of animal lives, there are other advantages to a non-meat meal. For example, 90% less greenhouse gases and 46% less energy is used to make non-meat burgers than meat, according to a study by the University of Michigan (comparing the Beyond Meat burger to a beef burger).

Based on a comparative assessment of the current Beyond Burger production system with the 2017 beef LCA by Thoma et al, the Beyond Burger generates 90% less greenhouse gas emissions, requires 46% less energy, has >99% less impact on water scarcity and 93% less impact on land use than a ¼ pound of U.S. beef.

Heller, Martin C. and Gregory A. Keoleian. (2018) “Beyond Meat’s Beyond Burger Life Cycle Assessment: A detailed comparison between a plant-based and an animal-based protein source.” CSS Report, University of Michigan: Ann Arbor 1-38.

Then there are the properties of the protein itself. Being plant based, the protein contains all essential amino acids. Nine of the 22 amino acids found in protein have to be taken up through food and the best source are plants – mammals simply can’t make them.

As we learned, adding more peas to your life might just be a good idea. We composed a handy pea-filled sentence to remind you to eat your vegetables peas.

Pursuing processed plant protein products permanently permits prosperous personal proliferation.

(this sentence counts towards your ten-pea-a-day)

Even though the Beyond Burger sold out in Germany within a couple of hours, more and more plant based meat alternatives appear on the market.

So maybe it’s time you give peas a chance when you light your next barbecue.

References

Overview over textured protein production processes

Overview over seed storage proteins

Overview over pea protein

Study comparing the Beyond Burger and conventional beef by the university of Michigan

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