Plant Protein
Click on the links below to find out more on:
- What is plant protein?
- Current demand for plant protein in Europe
- Benefits of plant protein crops
- Adding value to plant protein
- Products derived from plant protein
What is plant protein?
Protein is an essential nutrient that fuels the growth and metabolism of all living organisms. That which is derived from plants is by far the most abundant source available globally and is highly significant in the formulation of diets for both livestock and humans. The human demand for plant protein within a particular region of the world is often closely aligned with the relative economic development of that region, with populations in less developed regions sourcing their protein requirements directly from plant-based sources.
Within Europe due to the relative affluence of the region, plant proteins tend to be a source of nutrition for livestock, which in return provides animal-based protein sources for human consumption. This has resulted in the predominance of plant based protein sources such as cereals and grassland due to their suitability to grow in most regions in Europe. Oilseeds are by far the most commonly grown protein source for the livestock industry within Europe.
There are several other high yielding protein crop alternatives suitable to the pedoclimatic conditions within Europe. Of these faba beans, field peas, lentils, lupins, chickpea and soya are most commonly grown. These crops are grown, however, to a much lesser extent throughout Europe due to their relatively low return and the absence of stable markets. This sale of the majority of these crops into lower value markets such as the livestock feed sector and the lack of large scale processing facilities to transform these products into human edible feedstuffs are preventing farmers from gaining maximum value for their crop.
Current demand for plant protein in Europe
As previously mentioned the livestock sector is one of the biggest consumers of plant protein in Europe with almost 70% of all plant protein available in the EU, consumed by the pig and poultry sectors. A large proportion of this again is in the form of imported soya bean meal, which is a much sought after protein source due to its high protein concentration and good amino acid balance. The potential exists to displace a proportion of this market with protein crops of European origin.
Due to concerns around environmental sustainability and animal welfare, European consumers are also demanding more plant based products. The plant based food industry in Europe grew by ~49 % between 2018 – 2020 and generated a net sales value of ~€3.6bn. This contradicts the levels of protein cop production in Europe with over 1/3 of all plant protein consumed by EU citizens being imported.
Benefits of plant protein crops
For Consumers:
- High in Fibre, protein and many vitamins/minerals
- Low cholesterol
- Can contribute to climate resilient and circular food systems
For Agriculture:
- High yield potential for cool-season legumes due to the temperate and humid Irish climate. Ireland consistently yields the highest for peas and beans compared to the other 26 European Union countries
- Excellent break-crop in cereal rotations, impeding the build-up of cereal diseases, pests and weeds Potential to include in a combi-cropping arrangement with cereals or indeed other legumes
- Legume protein crops promote biological nitrogen fixation, which allows for lower inputs (no nitrogen application in legume crop plus potential to decrease input of N for following crop)
- Improve soil quality through beneficial effects on soil biological, chemical and physical conditions
- Improve biodiversity, especially in regards to promoting insect pollinators
- Increase the resilience of farming systems through crop diversification. At the moment, European agriculture heavily relies on only a few core crops. Expanding this will diversify the risk of crop failure due to extreme weather events
Adding value to plant protein
Plant protein can be extracted to form many products.
Plant Protein Flour: The initial step post-cleaning and removal of hulls / seed coats is milling for the production of flour
Plant Protein Concentrate: The above flour can be further processed by air classification. This involves the separation of small proteins from larger starch and fiber granules by passing through a circulating air stream. The separation occurs based on size and density of particles producing a course and fine fraction; the former is not moved by air while the latter experiences translocation to produce protein concentrate. Air classification will increase the protein content in the flour to between 60-80% protein. Plant protein concentrate can also be produced by a wet process similar to the one used to produce plant protein isolate described below but air classification is becoming more popular due to reduced water and other resource use.
Plant Protein Isolate: An alternative to the production of protein concentrate is the production of plant protein isolate (>80% protein). The most common method to produce protein isolate is pH extraction, this involves increasing the pH to >pH7 where the protein is most soluble the fiber and starch can then be removed by a centrifugation process. Then to remove the protein from say soluble sugars and oligosaccharides the protein is brought to its iso-electric pH where it will precipitate. The precipitate is then washed, neutralized and spray dried to produce a protein isolate (>80% protein) ingredient.
Products derived from plant protein
There are many plant protein products that can be produced such as breads, snacks, biscuits, pasta, processed meats, beverages, sauces.
Benefits of including plant protein in foods:
- Enhanced protein, soluble/insoluble fibre, resistant starch, lower glycaemic index, good for gut health, increased B vitamins
- Many plant proteins don’t contain sulphur-containing amino acids, therefore in baking when combined with e.g. wheat flour, the blend results in a well-balanced essential amino acid profile
Things to consider/challenges as ingredients:
- Plant proteins can contain anti-nutritional compounds (phytates, tannins, vicine, covicine, enzyme inhibitors) and can have ‘beany’ sensory attributes.
Processing to overcome these challenges:
- Soaking, boiling, toasting, microwaving, fermenting, germinating, dehulling – can de-activate the anti-nutritional compounds.
On the ingredient side flours, protein concentrates and protein isolates are ingredients that can be used to convey a function in various consumer products we use daily for example:
Plant protein emulsions – i.e. drinks that contain plant protein where the plant protein is stabilized to ensure oil and water in the beverage do not separate
Plant protein supplements - e.g. plant protein isolates used as sports recovery drinks
Plant protein flour – used to fortify bread / biscuits etc. Plant protein flours for use in baking are currently under review by Teagasc researchers in terms of their techno-functional properties such as gelling, water holding capacity, emulsion stability, structural effects, product volume and density, dough rheology, internal structure, crumb staling, sensory acceptability and nutritional composition.
Edible Coating: Plant protein isolates have been used to produce edible packaging / coating to protect other foods.
Further Details
Teagasc researchers are currently coordinating two large-scale projects looking at the development of the plant protein industry in Ireland and in Europe. Further details on these projects can be found at the links below:
