Research is revealing how kokumi peptides – compounds that enhance mouthfeel, depth, and richness – can naturally amplify flavours in foods from aged cheeses to low-sodium meats and plant-based alternatives.
These findings suggest kokumi-active compounds may be key to achieving robust flavours in health-conscious foods without added sodium or artificial additives.
In recent years, other scientists have revealed more about kokumi’s role in flavour retention for low-sodium foods and found new ways for kokumi ingredients to improve plant-based and fermented products. All of these scientific discoveries help grow the still limited understanding of the mechanisms behind kokumi’s effects.
The most recent study, published this month in Food Chemistry and conducted by scientists from the Technical University of Munich, found that kokumi-active peptides, particularly γ-glutamyl dipeptides like γ-Glu-Cys and γ-Glu-Gly, accumulate significantly as cheese ripens, lending mature varieties like Gouda and Parmesan their characteristic mouthfeel and depth.
Analysing 122 cheese samples with ripening times from two weeks to 15 years, the researchers found that older cheeses had significantly higher levels of γ-glutamyl peptides, especially γ-Glu-Cys and γ-Glu-Gly. They also found that the peptides build up predictably over time, contributing to a richer, more complex taste profile.
The researchers built a new database of 56 γ-glutamyl peptides to help producers track kokumi development under varying ripening conditions. The database, combined with a high-throughput liquid chromatography–mass spectrometry (LC-MS) monitoring technique, could help producers better understand how to achieve flavour-rich profiles.
By adjusting factors such as humidity, temperature, and microbial strains, producers could boost kokumi-active peptides during ripening to achieve specific flavour profiles more consistently.
While cheese ripening naturally boosts kokumi-active peptides, recent findings show the benefits of these compounds in other foods, particularly low-sodium products. Research published last year highlighted kokumi’s potential to maintain taste complexity in low-salt dry-cured ham.
Y-glutamyl peptides like γ-EF and γ-EW were found to restore the savoury, lingering qualities typically lost when sodium is reduced. Kokumi peptides compensated for the flavour gap, with researchers noting that “kokumi activity of … short γ-glutamyl peptides found in dry-cured ham elaborated with a reduced content of salt might counteract the sensory deficiencies produced by the salt restriction and improve the taste of the final product”.
Published in the journal Foods, this study suggests kokumi’s application could extend to other savoury products like sauces, snacks, and prepared meal. For producers aiming to meet lower-sodium targets without sacrificing taste, kokumi offers a natural alternative to synthetic flavour enhancers, providing strong, complex flavours in processed foods.
Plant-based products, often lacking the sensory depth of animal-derived foods, could benefit from kokumi’s effects – particularly in combination with monosodium glutamate (MSG), which supports kokumi-active compounds in binding to the calcium-sensing receptor (CaSR). Research from last year found that MSG not only enhances umami but also intensifies kokumi’s sensory effects, increasing qualities like mouthfeel and roundedness.
Published in the Science of Food, the study describes this synergy as providing a model for achieving complexity in foods such as vegan burgers, dairy-free cheeses, and even cultivated meat, where achieving the same depth as animal-based products can be challenging. The researchers noted that “[Achieving a] good balance of umami and kokumi substances … gives a scientifically useful background for providing newly developed foods, including cultured meat and plant-based meat substitutes, with good taste characteristics.”
Another study from earlier this year in the Journal of Agricultural and Food Chemistry explored how fermentation with Lactobacillus johnsonii can enhance kokumi in pea protein-based beverages. The fermentation process was shown to reduce bitterness and create six new taste-active peptides, including γ-Glu-Leu and γ-Glu-Tyr, which contribute to mouthfeel and roundness in the beverage.
The researchers used sensoproteomic analysis to identify the enzymes in L. johnsonii that produce kokumi-active peptides, highlighting fermentation as an effective technique for enhancing flavour complexity in vegan and dairy-free products.
The studies into specific food types build on insights into kokumi’s effects that emerged from a 2022 study in the Journal of Future Foods, which used molecular docking and dynamics simulations to examine how kokumi peptides bind to CaSR receptors. Peptides like γ-Glu-Cys-Gly, γ-Glu-Leu, and γ-Glu-Tyr were found to bind effectively with CaSR, primarily through hydrogen bonding and hydrophobic interactions. Key amino acids like Arg66, Ser147, and Ala168 in the receptor were identified as critical for kokumi binding.
Fundamental research published in Scientific Reports in 2021 explored kokumi perception differences between humans and carnivorous species, specifically the domestic cat, to better understand CaSR function.
This comparative study found that while the CaSR receptor in both humans and cats binds kokumi-active peptides, cats responded differently to certain kokumi compounds. “[O]ur in vivo data shows that cats are sensitive to CaCl2 as a kokumi compound, but don’t show this same activity with glutathione, whereas for humans the reverse is true,” the study noted. “[K]okumi is an important taste modality for carnivores that drives the palatability of meat-derived compounds such as amino acids and peptides, and … there are differences in the perception of kokumi taste between carnivores and omnivores.”
These findings indicate that while kokumi’s mouthfeel and flavour-enhancing properties are significant across species, individual taste receptors may respond uniquely. This variation could be useful in fine-tuning kokumi applications in human food, where the interaction between CaSR and specific compounds may differ based on product composition.
Together, these findings show that kokumi peptides can provide a natural path to rich flavours across food categories. From enhancing depth in aged cheeses to maintaining flavour in low-sodium and plant-based foods, kokumi compounds offer producers the tools to create satisfying flavours. With an expanding understanding of how kokumi peptides develop and bind in foods, there is potential for broad applications in both traditional and innovative food products.
