Food scientists at the National University of Singapore (NUS) have developed a novel fermentation process that significantly enhances both the nutritional value and flavor profile of kombu, a type of seaweed, potentially unlocking its wider use as a functional food ingredient. The research, published in the International Journal of Food Microbiology on , details how a co-fermentation process utilizing lactic acid bacteria (LAB) and aroma-producing yeast can improve nutrient absorption while mitigating the strong odors that often limit consumer acceptance.
Kombu (Saccharina japonica) is a staple in the cuisines of Japan, Korea and China, recognized for its high nutritional content. However, its dense cellular structure often traps nutrients, reducing their bioavailability. Simultaneously, its characteristic “fishy” or “grassy” aroma can be a barrier to broader consumption. The NUS team aimed to address both these challenges concurrently.
By combining enzymatic treatment with LAB and yeast co-fermentation, the researchers created a probiotic kombu blend that not only improves nutrient bioavailability but also enhances its flavor. This approach builds upon previous work demonstrating that enzyme-assisted LAB fermentation can release trapped nutrients, and extends it by introducing yeast to generate more desirable aroma compounds.
Laboratory analysis revealed that co-fermentation improved the survival rate of probiotics compared to LAB-only fermentation. Crucially, the process also increased levels of γ-aminobutyric acid (GABA), a bioactive compound linked to calming effects, stress reduction, and potential mental health benefits. The co-fermentation process significantly reduced undesirable off-flavors while introducing fruity notes reminiscent of banana and pear aromas.
“Kombu has a tremendous amount of untapped potential to be a superfood, but for its health benefits to reach a wider population, kombu has to be more palatable and its nutrients more accessible,” said Associate Professor Liu Shao Quan from the Department of Food Science and Technology at NUS Faculty of Science. “While enzymatic treatment followed by lactic acid bacteria fermentation liberates beneficial nutrients, the combination with yeast fermentation further produces fruity aroma compounds, improving the flavour profile of the fermented kombu.”
Commercial Potential for Functional Seaweed Ingredients
The resulting co-fermented kombu blend is enriched with probiotics and GABA, offering potential benefits for both gut and mental health. Researchers suggest this opens opportunities for a new generation of seaweed-based functional foods and beverages that deliver benefits beyond basic nutrition. This could include fermented seaweed drinks, probiotic supplements, or even incorporation into plant-based food products.
Dr. Lu Yuyun, Senior Research Fellow and co-corresponding author of the research paper, added: “Our unique co-fermentation method of processing kombu is the gateway to creating new health products. With our tastier fermented kombu, we could create fermented seaweed drinks, probiotic seaweed-based supplements or even use it as ingredients in plant-based foods. This approach may also be adapted to other seaweed species to broaden the range of appealing seaweed-derived products.”
Currently, few commercial kombu products utilize LAB-yeast co-fermentation, highlighting the technical novelty and potential industry relevance of this process. The NUS team is now focused on refining the fermentation parameters to improve scalability and facilitate product development.
Ms. Geng Chenhan, a third-year PhD student and first author of the research paper, concluded: “Elevating the flavour profile of kombu makes it more enticing to a broader range of consumers. Our next goal is to optimise fermentation conditions, such as fermentation sequence, time and temperature, to further improve process efficiency and product quality. In future, we will also conduct sensory evaluation to better understand consumer preferences for seaweed-based foods.”
The development comes as interest grows in exploring “kokumi,” a flavor-enhancing sensation found in fermented and aged foods, as a potential sixth basic taste alongside sweet, salty, sour, bitter, and umami. While scientists are still debating the precise nature of kokumi, the NUS research demonstrates a clear pathway to enhancing the palatability of seaweed through fermentation, potentially tapping into this complex flavor profile. The process also aligns with broader trends in the food industry towards utilizing fermentation to improve both the nutritional value and sensory experience of plant-based ingredients.
