For years, protein ingredients were evaluated through a very simple question: how many grammes per serving? This logic remains useful for comparing products, but it is no longer sufficient to judge their true nutritional value. In 2026, the scientific literature shows that we need to think in terms of protein quality, digestibility, food matrix and the complementarity of sources, rather than raw quantity alone.
Why the gram is no longer enough for protein ingredients
Two foods can display the exact same protein content while having a very different nutritional effect. The reason comes down to the essential amino acid profile, their bioavailability and the way the food is structured. The review published in 2026 in Comprehensive Reviews in Food Science and Food Safety emphasise that the PDCAAS and DIAAS scores assess foods in isolation, whereas in real life, proteins are consumed in meals, menus and daily diets where the sources complement each other.
This limit is particularly important for plant proteins. Their amino acid profile is sometimes less balanced than that of certain animal proteins, but the complementarity between cereals, pulses and other sources often makes it possible to correct this shortfall. In other words, an ingredient that looks weaker on paper can become very appealing once incorporated into a formulation or a balanced meal.
The food matrix is a game changer
The nutritional value of a protein does not depend solely on its chemical composition. It also depends on its food matrix in which it is taken. The 2026 review on plant proteins reminds us that processing can improve digestibility, but can also reduce the availability of certain amino acids, notably lysine, which is sensitive to thermal treatments and Maillard reactions.
This is a key point for manufacturers: an isolated protein does not behave in the same way as an enriched biscuit, a protein drink or a textured bar. Fibre, lipids, starch, water and technological processes alter amino acid release, digestion speed and sensory acceptability.
Be careful with sulphur-containing amino acids
An often underestimated angle in the debate on plant-based proteins concerns the sulphur-containing amino acids, particularly methionine and cysteine. The 2026 review of Sustainable Food Technology emphasises that several processing methods can reduce their bioavailability through oxidation, cross-linking or the Maillard reaction
This is important because a protein can remain “high in protein” on paper whilst losing some of its functional quality. The authors also point out that conventional analytical methods may overestimate the actual content of available sulphur-containing amino acids, which makes it difficult to interpret technical data sheets and claims. For fortified formulations, this argues in favour of more detailed measurements than simply the total protein content.
Alternative proteins are not all created equal
Alternative proteins are attracting a great deal of attention, but they do not form a homogeneous group. A 2026 study published in Food Chemistry evaluated microbial and insect proteins using the INFOGEST digestion model. The results show that digestibility and even the estimation of the true protein content can vary significantly depending on the source and the nitrogen calculation method.
This is an important reminder: a “protein-rich” ingredient on a technical data sheet is not necessarily of high nutritional quality. If part of the nitrogen is not in protein form, or if digestibility is poor, the real benefit diminishes. For protein ingredient formulations, it is therefore necessary to look beyond the marketing indicator and examine the biological performance of the ingredient.
Rethinking products enriched with protein ingredients
Protein-enriched products do not automatically become better quality simply because they contain more grams of protein. A 2026 review on protein fortification of cereals shows that these products can improve the amino acid profile and overall protein intake, but only if the formulation takes into account digestibility, satiety and sensory quality.
This sensory aspect is by no means secondary. A 2026 study on a cocoa-based drink enriched with alternative proteins shows that the protein source affects viscosity, texture and acceptability. If the product is not well received, it will be consumed less, and its actual nutritional value will decline accordingly.
Towards a “whole diet” approach”
Perhaps the real conceptual breakthrough of 2026 lies here: we need to move away from a “single food” approach towards a “whole diet” approach. The review by Nudel and Kerem proposes a framework for protein quality of the overall diet which aggregates indispensable amino acid contributions at the daily dietary level, rather than at the level of an isolated food.
According to this approach, the Mediterranean diet, the DASH diet or certain pregnancy diets may have an underestimated protein quality if only individual foods are taken into account. By applying this framework, the authors obtain corrected 18% to 30% values that are higher than those obtained using conventional calculations based on the sum of individual products. For applied nutrition, this changes the way protein ingredients are formulated, assessed and communicated.
Conclusion: protein ingredients no longer justify the price increase
The “gram war” is becoming less relevant. In 2026, scientific evidence shows that protein quality depends on the amino acid profile, digestibility, food matrix, processing methods and the complementarity between foods. When it comes to protein ingredients, the real question is no longer simply “how much does it contain?”, but how, in what context and with which other ingredients this gram actually works.
References
- Nudel A, Kerem Z. From Single Foods to Whole Diets: A Critical Framework for Assessing Protein Quality, Taking into Account Complementarity and Matrix Effects. Rev. Food Sci. Food Saf. 2026;25(4):e70571. DOI: 10.1111/1541-4337.70571. “Whole-diet protein quality” framework, amino acid complementarity, matrix effect, correction from 18% to 30% versus conventional calculations. pubmed.ncbi.nlm.nih
- Patrícia et al. Nutritional quality and processing of plant proteins for healthy and sustainable foods. Proc Nutr Soc. 22 January 2026: 1–9. DOI: 10.1017/S0029665126102213. The role of processing on digestibility, amino acid availability and nutritional quality. pubmed.ncbi.nlm.nih
- Graham R, Motta de Matos A, Parr T, Brameld JM. Evaluating the quality of novel alternative protein sources (microbial and insect proteins) using the INFOGEST in vitro digestion model. Food Chem. 2026;501:147468. DOI: 10.1016/j.foodchem.2025.147468. Digestibility and nitrogen assessment of alternative proteins. pubmed.ncbi.nlm.nih
- Plant proteins for human health: the current situation and future needs. Food Funct. 2026;17(4). DOI: 10.1039/D6FO00549G. The role of plant proteins in human health and the importance of the food matrix. pubs.rsc
- Plant-Protein Fortification of Cereal Foods: Market Insights and Nutritional Implications for the Dietary Exposome. Annu Rev Food Sci Technol. 2026; publication of 5 Feb. DOI: 10.1146/annurev-food-052924-062915. Cereal fortification, nutritional quality and formulation. pubmed.ncbi.nlm.nih
- Influence of Alternative Protein Sources on the Physicochemical Properties and Sensory Evaluation of a Buffalo Whey-Based Cocoa Beverage. J Food Sci. 2026;91(4):e70999. DOI: 10.1111/1750-3841.70. Texture and acceptability according to protein source. pubmed.ncbi.nlm.nih
FAQ
1. Why not just rely on the number of grams of protein?
Because two foods with the same total protein content can have very different qualities depending on their digestibility, amino acid profile and food matrix.
2. Are plant proteins of lower quality?
Not necessarily. They can be very interesting if they are well combined, well formulated and consumed as part of a varied diet. The problem is not the absolute “value”, but the actual quality and the context of consumption.
3. What is the matrix effect?
It is the idea that a nutrient does not act alone, but within a complex food structure. Structure, texture and the interactions between components modify digestion, absorption and the physiological effect.
4. Are alternative proteins all equivalent?
No. Microbial, insect or plant proteins do not have the same digestibility or the same compositional quality. They must be evaluated on a case-by-case basis.
5. Is a product higher in protein always better?
No. A product can be richer in grammes but less interesting if it is less digestible, less balanced in amino acids or less acceptable from a sensory point of view.