New Study Reveals How Pea Protein Hydrolysates Impact Satiety

Researchers from the Leibniz Institute for Food Systems Biology at the Technical University of Munich have conducted a study demonstrating that different hydrolysates derived from pea protein affect satiety in varying ways. Published in the journal Molecular Nutrition & Food Research, this research offers insights that could aid in the creation of new plant-based foods aimed at weight management.

Protein hydrolysates are formed by breaking down proteins into smaller fragments, including peptides and amino acids. These ingredients are becoming increasingly vital in the production of plant-based foods, which are gaining popularity due to their lower environmental impact compared to animal-derived products. Despite their advantages, many hydrolysates possess a bitter taste that can deter consumers.

Katrin Gradl, the study’s lead author, pointed out that this bitterness arises from specific peptides and free amino acids. Nevertheless, emerging research indicates that these bitter compounds could play a role in enhancing feelings of fullness. Some studies suggest that less extensively hydrolyzed proteins may slow gastric emptying, while more extensively hydrolyzed proteins might prompt a quicker hormonal satiety response in the intestines.

Pilot Study on Satiety Regulation

To explore these hypotheses, the research team, led by Veronika Somoza, conducted a pilot study involving 19 overweight men with a body mass index (BMI) ranging from 25 to 30 kg/m². Participants consumed 15 grams of one of two different pea protein hydrolysates two hours before a test breakfast on separate days. Hydrolysate H1 was characterized by a less bitter taste and a higher degree of hydrolysis (35%), while Hydrolysate H2 was more bitter and less hydrolyzed (23%).

The researchers tracked participants’ energy intake during breakfast, allowing them to eat freely, and measured gastric emptying rates along with hormone levels in their blood.

The results revealed that participants who ingested the more bitter Hydrolysate H2 experienced delayed gastric emptying and consumed approximately 126 kilocalories less at breakfast. In contrast, Hydrolysate H1, which had a lower bitterness and higher hydrolysis, significantly reduced levels of ghrelin and DPP4 in the blood. Lower levels of ghrelin, a hormone associated with hunger, signal the body to feel less hungry, while reduced DPP4 levels prolong the activity of satiety hormones.

Somoza explained, “Our results show that both hydrolysates influence the feeling of satiety in different ways. Hydrolysate H2 quickly made the subjects feel full, so they ate less. Hydrolysate H1, on the other hand, had a delayed effect and presumably promotes a longer-lasting feeling of satiety between meals.”

Implications for Functional Food Development

The study underscores the importance of both bitterness and the degree of hydrolysis in the effectiveness of protein hydrolysates for satiety regulation. These findings hold potential for the development of functional foods that can naturally assist in reducing energy intake, catering to the growing demand for plant-based dietary options.

The body mass index (BMI) serves as a key metric in this research, helping categorize individuals as underweight, normal weight, overweight, or obese based on their height and weight. The study’s findings could have significant implications for nutrition strategies aimed at weight management, particularly as the market for plant-based proteins continues to expand.

Pea protein hydrolysates available today typically fall under the category of partial hydrolysates, produced through chemical or enzymatic processes. The degree of hydrolysis reflects how many peptide bonds within the protein have been broken down, influencing the size of the remaining protein fragments and amino acids.

With increasing interest in plant-based nutrition, this research lays the groundwork for new developments in food science, highlighting the intricate relationship between protein structure, taste, and body response. Further studies may build on these results to refine dietary strategies that promote health and well-being.