Pulses for Human Consumption: Drying, Sorting and Storage

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Growing interest among Danish organic farmers in cultivating pulses such as lentils, faba beans, and peas for human consumption raises the question of how such crops should be handled during harvest and storage. When a crop is sold as food, the quality requirements are stricter than for feed crops. There are also often small batches that must be handled separately and with great attention to cleanliness - especially since the product typically must also be guaranteed gluten-free.

Technical solutions under investigation

There can be additional work and necessary investments associated with producing faba beans, lentils, peas, and similar crops for food use. The task should not be underestimated; food use must be considered throughout the entire chain - from the field to the buyer - emphasizes Special Consultant Lars Egelund Olsen, Innovationscenter for Økologisk Landbrug.

He has contributed to collecting experience and knowledge about processes and technical solutions that can work on farms when it comes to gentle handling, rapid drying, safe and hygienic storage, sorting, and cleanliness.

“These are often late crops that may have to be harvested with a high moisture content. The crop may for various reasons have been grown in a mixture with cereals that must be separated, and finally it may involve specialized productions down to perhaps five tonnes or less. This requires special silo and drying conditions, but also different handling already in the field,” explains Lars Egelund Olsen, who has visited organic farmers and companies in an effort to create an overview of suitable methods.

The work takes place within the project “Healthy and Tasty Pulses”, where one of the goals is to guide farmers towards successful production.

Think through the entire process

- Many of the machines and systems we use in feed production are not designed to be completely clean. There are always some kernels left in augers, elevators or in a corner of the combine harvester. That is not acceptable when we produce gluten-free products," says Lars Egelund Olsen.

Below you will find a guide to gluten-free production with a focus on options, requirements and economy:

Guide: Gluten-free crop production (pdf, 7 p.)

There are a number of issues to consider when handling pulses for human consumption:

Gentle harvesting and minimal handling

There is a high risk of cracking or damaging the kernels during harvest, especially when the seeds have a high moisture content, and kernel quality is particularly important for food use. Therefore, the harvested product should be handle as gently as possible. Harvest directly into big bags, boxes, or containers, which can then be transported to storage and dried without passing through augers and elevators.

Cleaning both before and after drying

It can be advantageous to clean the raw material both before and after drying. Before drying, wet and larger impurities can be removed, making the drying process easier. After drying, lighter impurities can be separated. A screen cleaner can be useful for this purpose, and the on-farm drying and cleaning can later be followed up by professional fine cleaning.

Rapid drying at low temperatures

High temperatures can damage quality, so the choice of drying system is important. A continuous-flow dryer operates with high heat for a short time and is most suitable for larger batches. A batch dryer can handle smaller quantities at lower temperatures. Small batches can also be dried in closed boxes or big bags. For example, Gl. Buurholt offers such solutions and specializes in developing mobile cleaning systems.