Cowpea research at TUM explores legume’s potential as a sustainable protein source

Researchers at the Technical University of Munich (TUM) have been investigating the potential of cowpea as a future protein source for human nutrition, as interest grows in climate-resilient crops and alternatives to imported soy.

• Doctoral researcher Victor Christian Kaharso investigated cowpea proteins and processing methods at the Technical University of Munich.
• The project focused on germination as a way to reduce antinutritional compounds and improve functionality for food applications.
• Researchers said cowpea could support more resilient food systems in both tropical and temperate regions.

Victor Christian Kaharso, a doctoral candidate from Indonesia, began research at TUM in October 2024 within the Plant Proteins and Nutrition group led by Prof. Ute Weisz. His work focused on cowpea (Vigna unguiculata), a drought-tolerant legume already widely cultivated in parts of Asia and Africa, primarily as animal feed.

Kaharso said the crop had significant untapped potential for human nutrition.

“I would like to explore the potential these beans hold for human nutrition through my work,” he said.

Cowpea contains around 20-25% protein and up to 60% carbohydrates while remaining naturally low in fat. The legume also contains iron, magnesium, and B vitamins. Researchers highlighted its heat tolerance and drought resistance as increasingly important characteristics as climate change places additional pressure on agricultural systems.

The project explored how cowpea proteins and starches could be isolated, characterized, and processed for food applications ranging from flours to plant-based products.

Researchers also examined the crop’s potential role in Europe. Kaharso noted that cowpea could potentially serve as a locally cultivated alternative to imported soybeans, helping support more resilient regional food systems.

A major focus of the research centered on overcoming antinutritional compounds naturally present in cowpeas. These compounds can interfere with mineral absorption, inhibit digestive enzymes, and contribute to gastrointestinal discomfort, limiting the crop’s wider use in food manufacturing.

To address this, the project investigated germination as a natural processing strategy.

Researchers said germination could reduce antinutritional factors while also modifying protein and starch structures in ways that improve functional properties such as solubility and gel formation. These characteristics are considered important for industrial food applications including bakery products and beverages.

The research program consisted of three interconnected studies.

The first examined twelve cowpea varieties, comparing differences in composition, structural organization, and the effectiveness of wet and dry fractionation techniques for isolating proteins and starches.

“I am interested in how the different varieties differ in the composition of their constituents and in the structure in which these occur within the beans,” Kaharso said.

The analysis focused on protein solubility, antinutritional compounds, and the structural organization of proteins and starches within the cowpea matrix.

The second study investigated how enzymatic activity triggered during germination degraded antinutritional compounds and improved nutritional quality.

The third explored how germination-induced biochemical changes altered the molecular structure of proteins and starches, affecting properties important for industrial food applications including solubility, gel formation, and processing suitability.

“My studies should provide both basic and practical knowledge of how cowpeas can be better utilized,” Kaharso said. “I will help to promote them as a potential plant-based food ingredient for more resilient and sustainable food systems in tropical and temperate regions.”

The research formed part of wider work at TUM examining how agriculture and food science can respond to climate change, biodiversity loss, and the need for more sustainable food production systems.