Harnessing pea protein and guarana extract for plant-based innovation

Research at the State University of Campinas (UNICAMP) in São Paulo, Brazil, has demonstrated the potential of a novel approach to enhancing plant-based proteins for the food industry. By combining heat-treated pea protein with guarana extract, researchers developed a compound capable of stabilizing an oil-in-water emulsion enriched with vitamin D3. This discovery offers a promising solution for creating healthier, nutrient-rich plant-based beverages. Conducted at the Process Engineering Laboratory of UNICAMP's School of Food Engineering, the study was supported by the São Paulo Research Foundation (FAPESP) and published in Food Research International.

The appeal of plant-based proteins lies in their ability to stabilize emulsions, form gels, and provide essential amino acids, yet poor water solubility often impedes their use in food and beverage formulations. This challenge inspired the researchers to explore methods for improving the solubility and functionality of pea protein. Heat treatment and conjugation with guarana extract—a plant native to the Amazon and rich in phenolic compounds—proved particularly effective. According to Marluci Palazzolli da Silva Padilha, the study’s corresponding author, “The addition of guarana extract enhances the protein’s capacity to stabilize emulsions, valorizing a bioactive-rich product of the Amazon.”

Pea protein is already valued for its affordability, low allergenicity, and emulsifying and gelling properties. However, its commercial application is hindered by issues such as off-flavors, gritty texture, and limited solubility in water. To address these barriers, the researchers tested the effects of heat treatment and guarana conjugation on pea protein, creating an emulsion with vitamin D3—a nutrient crucial for immune function and bone health but notoriously unstable in water-based solutions. Tests revealed that after 30 days of storage at room temperature and exposure to ultraviolet light, over 77% of the vitamin D3 in these emulsions remained intact. Additionally, simulated digestion experiments showed that bioavailability of vitamin D3 was higher in emulsions stabilized with the modified protein and guarana compared to those using pea protein alone.

The simplicity and scalability of these methods make them particularly appealing for industrial applications. Heat treatment at 90 °C for 30 minutes resembles the pasteurization processes already standard in food production, while pH adjustments to optimize interactions between phenolic compounds and proteins are commonly employed to refine flavor and ensure safety. Professor Rosiane Lopes da Cunha emphasized the broader implications of this approach, noting, “These findings open the door to developing plant-based emulsifiers with enhanced functional properties. Other plant proteins may also benefit from similar strategies to expand their use in the food industry.”

While the study demonstrated clear benefits, the researchers caution that optimizing protein modification depends on the specific composition of the plant protein and the phenolic extract used. This underscores the need for tailored approaches when developing functional food ingredients. The research illustrates the potential for creating value-added plant-based products while showcasing the versatility of guarana and its ability to contribute to sustainable food innovation. For more details, the article, Combining heat treatment and conjugation between guarana extract and pea protein isolate to produce O/W emulsions loaded with vitamin D3, is available in Food Research International.

(Main picture shows Marluci Padilha and Rosiane Cunha)