Processing pulses

Pulses, such as beans, chickpeas, peas, lentils and broad beans, are essential foods for human consumption and for the sustainability of the planet. Once harvested, these seeds undergo cleaning and drying stages and, in some cases, industrial processing, which makes them safer, tastier and easier to cook.

Cleaning and drying

Immediately after harvesting, the pulses are cleaned to remove stones, leaves and dust, and are dried in the sun (in traditional systems) or in hot-air dryers in an industrial setting. This process is important to prevent the growth of mould and to preserve the grain for longer.

 

Peeling and Milling

In some processes, the first step in processing is hulling, which involves removing the outer husk from the seed. The husk is rich in fiber and can be used to make animal feed or natural fertilizer.

In some cases, the grains are ground into flour, which is used in a variety of food products, ranging from pasta and bread to instant soups and gluten-free products.

There are two main types of milling:

  • Dry milling enables the separation of fractions with different physical properties, associated with different protein and starch contents;
  • Wet milling, in which the grain is mixed with water and the pH is adjusted to extract proteins, starch and fiber.
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The resulting flour can be divided into different fractions:

  • protein fraction, used to produce vegetarian burgers, pasta and biscuits;
  • a fraction rich in starch, used in porridges, sauces and baby food;
  • fibrous fraction, used in wholemeal cereal products or fiber supplements.

 

PROTEIN EXTRACTION

Pulses are excellent sources of plant-based protein. In factories, these proteins can be isolated using methods that involve water and variations in pH. This process yields protein concentrates (around 60–70% protein) and isolates (generally over 80% protein), which are used in the production of protein-rich foods such as plant-based shakes, energy bars and meat alternatives.

New technologies, such as ultrasound, high pressure and pulsed electric fields, can increase the efficiency of protein extraction and reduce water and energy consumption.

 

 

BY-PRODUCTS AND UTILISATION

Nothing is lost:

  • The peels are used as fertilizers or biofuels;
  • The fibers and starch are reused in animal feed, fortified products or biodegradable plastics;
  • Liquid waste is treated and reused, thereby reducing the environmental impact.

This comprehensive utilization forms part of what is known as the “circular economy”, with the majority of by-products being reused.



 

SUSTAINABILITY AND THE ENVIRONMENT

Pulses are among the most environmentally friendly crops. They reduce the need for nitrogen fertilizers due to their ability to fix atmospheric nitrogen. As a result, they improve the soil, reduce greenhouse gas emissions and save water, requiring far less water than meat production and many other animal-based foods.

That is why increasing your consumption of pulses is a simple way to improve your health and protect the planet.



 

A tip for planning your meals

Include pulses at least three times a week, in soups, salads, stews or vegetable burgers. When choosing processed products containing pulses (such as chickpea pasta or lentil snacks), check that they are low in salt and fat.

And remember: eating local and seasonal pulses helps to support Portuguese farmers and reduce the environmental impact of your diet.