Interest in plant-based food models continues to grow. Within the context of sustainability, foods developed through minimal processing methods aim to support healthier products while preserving their nutritional integrity.

However, the nutritional value of a food does not depend only on the amount of nutrients it contains. It is also important to understand how much of those nutrients can be released during digestion and how much can ultimately be absorbed by the body.

This is where the concepts of bioaccessibility and bioavailability become particularly important.

Within the Sustain-a-bite project, researchers are studying the effects of minimally processed plant-based products on the absorption of minerals and glucose using cell models.

What are bioaccessibility and bioavailability?

Bioaccessibility refers to the amount of nutrients released from the food matrix after digestion.

Bioavailability refers to the amount of those released nutrients that can enter the body through the human intestinal system.

A food product may contain high levels of minerals, but this does not necessarily mean that the body can fully use them. For this reason, the development of plant-based foods should consider both their techno-functional properties and their physiological effects.

“A high mineral content does not necessarily mean that the body can fully utilise those minerals.”

Studying iron, zinc and calcium

The Sustain-a-bite project will study the bioaccessibility and bioavailability of three essential minerals: iron, zinc and calcium.

Iron is involved in processes such as oxygen transport, energy production and cell division.

Zinc is present in the structure of more than 300 proteins and can influence gene regulation and immune response.

Calcium is a structural mineral and an essential component of bones and teeth. It also participates in physiological regulation through intracellular communication.

Plant-based ingredients can contain compounds such as oxalate and phytic acid, which bind to minerals and reduce their bioavailability.

Minimal-processing applications may help reduce the levels of these compounds and support intestinal absorption. The objective is not to increase mineral bioavailability excessively, but to bring it to an optimum level for the body.

The role of the food matrix

The structure of the food matrix is another important factor in nutrient absorption.

Solid foods may sometimes slow down absorption when compared with liquids. However, a longer digestion process may also spread nutrient absorption over time and extend the bioavailability process.

For this reason, the project will investigate the effects of different food matrices, including solid, semi-solid and liquid foods.

“The food matrix is one of the most important criteria for achieving optimum nutrient absorption.”

Studying glucose absorption

The research will also examine glucose, which is particularly relevant in relation to metabolic diseases.

The amount of glucose or digestible carbohydrates in a product is important, but so are its bioaccessibility and bioavailability after digestion.

The Sustain-a-bite project will therefore study post-digestion and post-absorption glucose levels in minimally processed foods presented in different forms.

Modelling the human intestinal system

To study nutrient absorption, the researchers use a bicameral cell system that models the human intestinal system.

The most important feature of this model is the formation of a cell monolayer with tight junctions.

The integrity of this monolayer is verified through TEER measurements, or Transepithelial Electrical Resistance.

Once the cell model has been established, it can be used in bioavailability studies to determine nutrient absorption rates.

Connecting health and sustainability

When developing plant-based foods, several interconnected elements must be considered: nutrient content, processing technology, techno-functional properties, bioaccessibility and bioavailability.

Without this integrated perspective, a product described as healthy may remain physiologically inadequate. At the same time, the correct processing method may help transform a food with a modest nutrient content into a more bioavailable source.

The Sustain-a-bite project applies this approach to bring science closer to everyday food and to ensure that sustainable nutrition considers both environmental and biological sustainability.