Phospholipids on a pea

Neutron reflectometry provides valuable insights into the molecular intricacies of plant-based food

To this day, one of humankind’s greatest challenges is to provide universal, stable access to food around the globe. While we currently rely heavily on animal-derived products, in particular to cover our protein requirements, numerous problems associated with an overconsumption of meat and dairy call for a switch to more sustainable protein sources.

Peas are sometimes considered a Swiss Army knife amongst alternatives to animal protein. They can be grown in various climate zones, cause few allergies and have a high protein content. Two types of pea proteins - legumin and vicilin, which differ strongly in their chemical properties - have been identified as being of particular interest for plant-based food. Their appeal is due to their ability to form films at oil-water interfaces. This implies that they help mix water-soluble components with oils and fats or create foams, which is highly appreciated in plant-based desserts or cappuccino. A detailed, molecular-level understanding of pea protein adsorption to fatty molecules is crucial for optimising the formulation, texture and mouthfeel of plant-based food.

“Interestingly, we saw that legumin did not seem to interact with the phospholipid film, even if we changed its composition.” Vicilin, on the other hand, changed its structure while also attaching to the phospholipid film. “When we constructed a mathematical model of our data, we were able to deduce that vicilin formed soluble molecular complexes with the phospholipid molecules”, adds Atıl.

This study, providing molecular-level insights into protein behaviour at lipid interfaces, is an important step towards a more general understanding of the hidden nature of plant-based foods. “With plant proteins becoming increasingly important alternatives to animal-based food, such research will help us guide the design of delicious, appealing plant-based products”, says Tommy Nylander, principal investigator of the study together with Milena Corredig.