TECNALIA obtains dietary fibre with different technological and functional properties

4 March 2024

TECNALIA obtains ad-hoc fibre from agri-food by-products

TECNALIA's Healthy Food team includes professionals with extensive experience in researching, designing and optimising processes for valorising compounds from agri-food by-products.  An example of this can be found in the recovery of fibre.

Imbalances between food availability and demand, due in large part to population growth and the effects of climate change, are putting pressure on natural resources. They also result in an urgent need to find new sources of ingredients and foodstuffs.

In this regard, millions of tonnes of by-products per year from the agri-food industry can be valorised to obtain high added-value compounds. They can also be incorporated into new food applications such as polyphenols, polysaccharides or fibres, thereby reducing stress in the agri-food chain and giving the sector a boost.

TECNALIA has been working for years on obtaining ad-hoc fibres for incorporation into different matrices and food applications. Many of the by-products from the food industry are made up of skins, pulp or food waste with a high fibre content, which can be recovered and fed back into the chain with added value. There are a number of different examples such as cardoons, artichokes and citrus by-products that have a high content of valuable fibre.

Dietary fibre and its different properties

TECNALIA’s centre does research into obtaining fibre with different technological and functional properties, assesses the most suitable extraction and stabilisation process and determines the most technically and economically viable strategies for the company.

Dietary fibre is essential for a healthy diet. It is found mainly in fruits, vegetables, whole grains and legumes. Although it is renowned for its ability to prevent or relieve constipation, fibre provides other health benefits.

Dietary fibre can be broken down into two types of fibre: soluble fibre that dissolves easily in water and can be found in citrus fruits, apples, peas, etc., and insoluble fibre found in wheat flour and vegetables such as cauliflower. The strategy to be followed will depend on the type of fibre and its purpose.

Technologies for recovering fibre

Some of the most important technologies used in fibre recovery include physicochemical technologies and the application of enzymatic processes.

  • Physicochemical technologies are widely used in obtaining fibre. They mainly consist of applying successive solid/liquid extraction steps with an aqueous solvent at different temperatures. The associated physicochemical processes need to be studied so as to preserve the quality of the fibre and other compounds of interest that can be found in the product.

As TECNALIA explained, “The application of extraction steps using solvents with a different polarity affects the type of fibre (soluble and insoluble), its capacity to hold water and the resulting particle size. Furthermore, applying successive washes can have a positive effect on removing the colour associated with the pigments in the sample”.

However, although temperature helps in the extraction of compounds from a food matrix, it can also cause undesirable effects due to the presence of sugar and the associated Maillard reactions. That is why TECNALIA also uses high-pressure extraction technologies and ultrasound extraction technologies (UAE) that improve the quality of the final product and preserve its properties.

  • Enzymatic processes are starting to play a very important role in sourcing ingredients. In the food industry, enzymes play a crucial role in obtaining dietary fibre as it is possible to modulate the properties of the final product by varying the type of enzyme, concentration, pH, etc.

Enzymes in obtaining foodstuffs

Enzymes are used to improve the quality and functionality of the fibre by hydrolysing cellular components and releasing natural fibres.

The main benefits of using enzymes can be summed up as follows:

  • Efficiency: enzymatic processes can be more efficient and selective than traditional chemical methods.
  • Product quality: enzymes make it possible to obtain fibres with specific properties such as size and solubility.
  • Sustainability: the biodegradability of enzymes contributes to more sustainable production.

In short, applying enzymes in the production of dietary fibre is a promising strategy for improving food quality and reducing environmental impact. As TECNALIA pointed out, “In certain cases, the effects of depectinisation are evaluated to modulate the properties of the fibre as a texturiser”. This makes it possible to develop fibre ingredients with different water absorption, texture, taste, smell, colour, etc. properties

The experience of TECNALIA's Healthy Food team in extraction, purification, stabilisation and analysis processes, and their knowledge of fruit and vegetable raw materials and how to obtain ingredients from them, provides an important technical advantage that responds to the needs of the industry.

Moreover, the equipment in the technology centre's laboratories makes it possible to access different extraction and encapsulation technologies. This means that TECNALIA is able to respond to the different needs and demands of the sector.

In fibre extraction processes, the research team is able to define the most suitable strategy for obtaining different water dispersible powder products with minimal colouring. These are applied in different food formulations after assessing the technical and economic feasibility of doing so.