In 2020, sales of more than 1 billion EUR were recorded as a new record high for the entire segment of vegetarian-vegan products, with plant-based alternatives to milk making up one of the strongest sales groups. Even though only a few people in Germany live a strictly vegan lifestyle, the willingness to buy alternatives to dairy products has steadily increased. The range of alternatives to dairy products is broad: from plant-based H-drinks to fermented products and cheese analogs. Depending on the temperature-time combination, plant fractions or individual subunits are denatured, which changes their structure and also their physical properties. For example, if one has a native extracted pea protein, a gel is formed when heated. With a comparable protein content, this is not possible with a pea protein isolate, since the proteins in the preparation are already partially or completely denatured.

We postulate that with quantitative analytics and a better understanding of thermally induced changes in plant protein fractions, processes can be designed and optimized for desired physical properties. Accordingly, this project focuses on the following:

• developing a HPLC (High-performance liquid chromatography) method to quantify individual plant protein fractions in raw materials, intermediates and final products
• determining the formal kinetics of thermal denaturation of the globulin fraction and its subunits and their interaction 
• characterizing and building understanding of changes in physical properties as a result of denaturation and, if applicable, aggregation of proteins 

The methods developed in the project for quantifying individual protein fractions of pea and oat can be used directly by food-producing companies and their suppliers as well as by analytical laboratories. They can be used to characterize starting materials for production, for example, to determine the extent and chemical-physical effects of denaturation in protein preparations. With such information, starting materials for the processing of plant alternatives can be qualified and thus be selected, or process parameters can be adjusted in order to achieve the desired quality level and to avoid faulty production.