Roquette’s Nutrition Research Manager, Elodie Dehay Harmel, on protein quality – the next frontier in nutrition science

As nutrition science moves beyond simple protein content, Roquette’s Elodie Dehay Harmel, Nutrition Research Manager, explains why digestibility, bioavailability and health outcomes are becoming the new measures of protein quality

Numbers are seductive. They fit neatly on the front of a pack, reduce complex science to something consumers can understand at a glance and make competing products easy to compare. Few nutrients have benefited from that simplicity more than protein. Across supermarket shelves, it has become shorthand for health, with increasingly prominent claims used to signal everything from fitness and satiety to weight management and healthy aging. Unfortunately, nutrition rarely conforms to the simplicity of a front-of-pack claim.

Researchers are asking questions that rarely featured in product development conversations a decade ago. How efficiently are amino acids absorbed? How does the food matrix influence digestion? Can different protein sources affect metabolic health in different ways? What role do they play in shaping the gut microbiome? And perhaps most importantly, what actually defines a high-quality protein?

Roquette’s Nutrition Research Manager, Elodie Dehay Harmel, believes the industry is entering a very different phase of development. “We’re definitely seeing a shift, with consumers turning to plant proteins for health reasons just as much as environmental or ethical ones,” she explains. “This is partly down to the growing body of evidence linking plant-forward dietary patterns with improved health outcomes, including lower risks of cardiovascular disease, type 2 diabetes and certain cancers.”

That changing evidence base is also reshaping the industry’s narrative. Sustainability remains one of the sector’s strongest selling points, but it is no longer the only one. Increasingly, the case for plant proteins is being made through the lens of personal health, giving consumers a reason to choose them not simply because they are better for the planet, but because they may be better for themselves.

The result is a more discerning marketplace. Protein content may still attract attention, but it is no longer the only measure of value. Increasingly, consumers want to understand what a protein contributes nutritionally, not simply how much of it a product contains.

“People are starting to look beyond protein content and calories alone, and weigh up the wider health benefits and nutritional density that plant proteins can offer. As they become more informed, they’re also considering factors such as protein quality, satiety, digestibility, fiber content and which ingredients can help them meet their own specific health and wellness goals.”

In many ways, this represents the industry’s biggest change in emphasis since plant proteins entered the mainstream. Attention is moving away from how much protein a product contains and towards the health outcomes that protein can help deliver.

Sustainability will always remain important, but the clear, evidence-based benefits of plant proteins in areas such as healthy aging, metabolic health, satiety and muscle maintenance are fast gaining ground with health-savvy consumers too

“Ultimately, we expect health functionality to become one of the defining growth drivers for the category,” says Dehay Harmel. “Sustainability will always remain important, but the clear, evidence-based benefits of plant proteins in areas such as healthy aging, metabolic health, satiety and muscle maintenance are fast gaining ground with health-savvy consumers too.”

The GLP-1 effect

Perhaps the biggest catalyst has come from an unexpected direction. The rapid rise of GLP-1 receptor agonists has fundamentally changed the nutritional priorities of millions of consumers. As appetite decreases, maintaining adequate nutrient intake becomes more challenging, placing greater emphasis on foods capable of delivering more nutrition in smaller portions.

Protein has emerged as one of the biggest nutritional priorities, helping address one of the principal concerns surrounding rapid weight loss: preserving lean muscle mass while overall food intake declines.

“The rise of GLP-1 medication use is likely to have an impact on protein consumption too,” Dehay Harmel says. “As appetite decreases, users are becoming increasingly focused on getting enough protein to help preserve lean muscle mass and maintain overall nutritional adequacy. This creates an opportunity for high-quality plant proteins that can deliver nutrient-dense nutrition in convenient formats that fit changing eating habits and lifestyles.”

Yet reducing the discussion to GLP-1 users would miss the bigger picture. Longer life expectancy, growing interest in healthy aging, personalized nutrition and a greater focus on metabolic health are all raising the same question: how can foods deliver more nutritional value in every bite?

The challenge is no longer simply to add protein. It is to extract as much nutritional value as possible from every serving.

Beyond muscle health

The implications extend beyond nutrition science itself. As researchers build a better understanding of the gut microbiome, attention is increasingly turning to the role individual ingredients may play in supporting digestive and metabolic health – areas once considered largely separate from discussions around dietary protein.

“One area of growing interest is digestive health,” Dehay Harmel explains. “Recent research suggests that shifting from an animal protein-rich diet to a more flexitarian eating pattern – that includes a greater proportion of plant protein sources – can positively influence the gut microbiota’s composition and activity.”

Those changes are about more than microbial diversity. Studies have also reported improvements in recognized cardiometabolic risk markers, including body weight, insulin resistance and LDL cholesterol, reinforcing the growing view that gut health and metabolic health are deeply interconnected.

The same pattern is beginning to emerge at the ingredient level. “A recent clinical study found that pea protein helped reduce post-meal blood glucose responses when consumed alongside carbohydrates,” she says. “What’s interesting is that the effect was achieved without the larger insulin response typically associated with some animal proteins, highlighting the potential for pea protein to support a more balanced metabolic response after eating.”

The significance extends well beyond pea protein itself. It reflects a broader shift in nutritional research, where protein is increasingly being evaluated not simply by its composition, but by its physiological effects after consumption.

For ingredient manufacturers, that changes the commercial conversation. Protein content alone is unlikely to remain a meaningful point of differentiation if competing ingredients can demonstrate measurable benefits for metabolic health, satiety or digestibility.

That, in turn, raises another question. If protein quality is becoming increasingly important, how should manufacturers communicate the fact that not all plant proteins are created equal?

Not all proteins are created equal

That question becomes particularly important because consumers often talk about pea protein as though it were a single ingredient. It isn’t. Two ingredients may both originate from the same crop, yet behave very differently depending on how they have been processed. Protein concentration, solubility, flavor, emulsification, water-holding capacity and digestibility can all vary, allowing manufacturers to select ingredients that are optimized for very different applications.

“The key is communicating the value that different production methods can bring,” says Dehay Harmel. “Not all pea proteins are the same, and understanding those differences is becoming increasingly important as manufacturers look to meet more specific nutritional, functional and formulation requirements.”

Explaining those differences may prove just as important as developing them.

Processing is often viewed negatively by consumers, yet modern ingredient technologies have dramatically expanded what plant proteins can achieve. Today’s manufacturers can select from ingredients with different protein concentrations, digestibility profiles, flavor characteristics and functional properties, tailoring solutions for everything from ready-to-drink beverages to high-protein snacks and meat alternatives.

One of the biggest misconceptions is that functionality and nutrition are competing priorities. In reality, there’s no reason why plant proteins can’t deliver both

“One of the biggest misconceptions is that functionality and nutrition are competing priorities,” Dehay Harmel explains. “In reality, there’s no reason why plant proteins can’t deliver both. Advances in processing technologies mean manufacturers now have access to a broad range of pea protein ingredients with distinct technical and nutritional characteristics.”

The challenge, she argues, is deciding how much of that science consumers actually need to hear.

“Rather than focusing solely on how a protein is produced, we could instead explain what those production methods enable. Does the ingredient perform better in a ready-to-drink beverage? Does it deliver a cleaner taste profile? Does it provide improved nutritional quality or functionality in a high-protein snack? Because these outcomes can really make or break consumer appeal.”

Plant proteins may follow a path remarkably similar to whey. Most consumers never set out to learn the differences between concentrates, isolates and hydrolysates – they simply came to recognize that each offered different benefits. Plant proteins may follow the same path.

“We’re already seeing this happen in categories such as ready-to-mix and ready-to-drink beverages, where terms like pea protein isolate or pea protein hydrolysate are becoming more familiar to consumers, much like whey protein categories have been for years,” she says. “There’s also growing interest in the science behind these products. Clinical research is helping build a deeper understanding of how different plant protein ingredients can support nutritional quality and specific health outcomes, giving manufacturers another way to differentiate products and communicate value.”

Defining protein quality

Throughout the conversation, Dehay Harmel returns to one phrase again and again: protein quality.

“We’ve spent years talking about how much protein a product contains, rather than how effectively that protein can support health outcomes,” she says. “That needs to change. The focus needs to move beyond quantity and towards quality.”

At first glance, it sounds like semantics. In reality, it marks one of the most important distinctions in modern nutrition science.

Protein quality is shaped by two fundamental questions. Does a protein contain the amino acids the body needs? And how efficiently can those amino acids actually be absorbed and used? Protein percentage alone cannot answer either.

“Amino acid profile is a key part of that,” Dehay Harmel explains. “Different protein sources contain varying levels of the essential amino acids that our bodies can’t produce themselves, and those differences influence how effectively protein can support functions such as metabolism, muscle maintenance, growth and overall well-being.”

Researchers have spent decades trying to answer those questions, leading to the development of recognized measures of protein quality such as the Protein Digestibility Corrected Amino Acid Score (PDCAAS). Despite the emergence of newer methodologies, it remains the most widely recognized global benchmark.

“PDCAAS remains a widely used, validated and globally recognized reference method in the food industry, providing a useful and practical benchmark for assessing protein quality across a broad range of applications,” she says.

Increasingly, however, researchers are looking towards the Digestible Indispensable Amino Acid Score (DIAAS), which measures the digestibility of individual indispensable amino acids at the end of the small intestine rather than relying on total protein digestibility.

The difference is important. Rather than treating protein as a single measurement, DIAAS evaluates the digestibility of individual indispensable amino acids, providing a more physiologically relevant picture of how a protein performs once consumed. It also makes it easier to distinguish between higher-quality proteins, particularly when they are used in blends.

We’ve spent years talking about how much protein a product contains, rather than how effectively that protein can support health outcomes. That needs to change. The focus needs to move beyond quantity and towards quality

“DIAAS shifts the focus from total protein to individual indispensable amino acids and measures their ileal digestibility, which more accurately reflects amino acid absorption in humans,” Dehay Harmel explains.

For all its advantages, DIAAS has one significant drawback. The gold-standard method relies on measuring ileal amino acid digestibility in humans - an invasive and technically demanding process that limits its routine use. That is why so much current research is focused on developing reliable in vitro models that can estimate DIAAS without the need for human studies.

Even then, no single score can fully define protein quality. “Other important but often overlooked factors include anti-nutritional compounds such as phytates or trypsin inhibitors, which can limit amino acid availability; food matrix effects, where the structure of the food influences digestion and absorption; and the kinetics of amino acid absorption, often described as the ‘fast versus slow protein’ concept, which can impact bioavailability and therefore muscle protein synthesis and satiety.”

Ultimately, protein quality doesn’t end with the ingredient. It ends with the food consumers actually eat.

“At Roquette, we focus on characterizing protein quality at the ingredient level, while collaboration with B2C partners is essential to assess the final nutritional quality within the finished food matrix, as formulation and processing can significantly influence amino acid bioavailability.”

Nutrition for the individual

For manufacturers, that creates a very different innovation challenge. Rather than developing products for the average consumer, the focus is shifting towards ingredients that can support increasingly specific nutritional objectives across different life stages and lifestyles.

“Today’s consumers are realizing that one size doesn’t fit all when it comes to nutrition,” says Dehay Harmel. “Rather than following broad dietary trends, many people are reaching for high-protein products that align with their individual health goals.”

Ingredient innovation is already moving in that direction. Manufacturers are developing proteins for specific life stages and physiological needs, while combining carefully selected amino acid profiles with complementary ingredients such as fiber and micronutrients to create more targeted nutritional solutions.

Perhaps the greatest sign of the category’s maturity is that it no longer needs to justify itself by comparison with meat. Increasingly, plant proteins are being valued for what they offer in their own right.

“Plant proteins already play an important role in functional foods and beverages, and this is only becoming more significant as consumer expectations evolve,” she says. “As consumers become more proactive about managing their health, they’re looking for foods and beverages that support healthy aging, metabolic health, weight management and overall wellness.”

Perhaps the biggest transformation, however, is one of perception.

“Plant proteins have come a long way in terms of taste and texture,” Dehay Harmel concludes. “In the past, consumers were willing to compromise on eating experience in exchange for health or sustainability benefits, but that's no longer the case. Taste remains the single most important factor influencing plant-based food purchases, and improvements in ingredient technology mean today's products can deliver on both nutrition and enjoyment.”

As the category matures, she expects manufacturers to move beyond simply replicating animal products and instead embrace the intrinsic qualities of plant ingredients themselves.

“Rather than focusing solely on replicating meat, there’s growing interest in products that celebrate the unique qualities of plants for what they are. Consumers are increasingly open to foods that showcase the flavor, texture and nutritional benefits of ingredients such as peas, fava beans and other plant protein sources, rather than trying to mimic animal-based products.”

This is an extended version of an exclusive interview conducted for the forthcoming nutrition edition of Protein Production Technology International. To receive the magazine free of charge, along with weekly news, exclusive interviews and technical analysis from across the future protein industry, subscribe here