Results and Discussion
The concept explored in this work centers on the potential of steamed soybeans to act as a natural agent for salt reduction in seawater, inspired by the role of soybeans in traditional miso production. To investigate this, static experiments were conducted using steamed soybeans and simulated seawater with an initial concentration of 3%, representative of typical ocean salinity.
The experimental setup involved immersing 100g of steamed soybeans in 100mL of simulated seawater for a static period of 1 hour at room temperature (25 °C, 56% humidity). A preliminary observation indicated that the salt adsorption capacity of the soybeans gradually weakened after approximately one hour. Based on this, the experiment involved sequential exchanges of steamed soybeans. After the first hour, the salt concentration in the simulated seawater decreased from 3.0% to 2.3%. The used soybeans were then replaced with a fresh 100g batch, and the process was repeated. After the second hour (with the second batch of soybeans), the concentration further reduced from 2.3% to 1.5%. A third exchange in the third hour brought the concentration down from 1.5% to 1.17%. Finally, a fourth exchange in the fourth hour resulted in a reduction from 1.17% to 0.89% (
Figure 2). This demonstrates a progressive and significant reduction in salt concentration through repeated exposure to fresh steamed soybeans.
A subsequent experiment was conducted with a lower initial salt concentration (0.89%) using 40g of steamed soybeans in 40mL of simulated seawater for 1 hour. This resulted in a further reduction to 0.77%. These results suggest that by repeatedly changing the steamed soybeans, it is theoretically possible to reduce the salt concentration in simulated seawater to levels approaching zero percent, potentially rendering the water suitable for drinking according to established standards (typically below 0.5-1% for palatability and health). The observed effectiveness of steamed soybeans in salt adsorption appears promising, and a preliminary observation suggests they may be more effective than other foodstuffs like okra in this regard.
An intriguing observation during these experiments was that applying a frequency of 116 Hz appeared to further enhance the salt reduction, decreasing the concentration from 3.0% to 2.2% in one hour compared to 2.3% without this low-frequency sound treatment.
The frequency of 116 Hz is of particular interest due to its appearance as a prominent peak frequency in studies related to human chanting practices. Specifically, 116 Hz has been studied in the context of chanting Nam-Myoho-Renge-Kyo and has been referred to as the "fundamental sound of life" (Hiratsuka and Wakae, 2019). More directly relevant to the observed salt reduction, previous research has indicated that exposure of seawater to a sound at 116 Hz for 30 minutes significantly reduced chloride ion concentration (Hiratsuka and Imamura, 2020). Given that chloride ion is the dominant physiological anion and plays a crucial role in balancing key cations like sodium, potassium, and calcium both in seawater and biological fluids, the observed reduction in salinity in the116 Hz experiment might be linked to this specific effect on chloride ions.
The biological significance of chloride ions, particularly within the central nervous system, where chloride channels are integral to maintaining electrical potentials, regulating cell volume, and influencing cell proliferation and programmed cell death, suggests potential broader implications. It can be hypothesized that if external stimuli, such as specific frequencies like 116 Hz, can modulate chloride ion behavior in aqueous systems (like seawater or even potentially biological fluids), this could hypothetically influence various biological functions, including brain activity, the function of other physiological systems, or even cellular responses relevant to conditions like cancer (for rev., see Ruggiero, 2024). Specifically within the context of oncology and radiation therapy, modulating ion homeostasis via non-thermal means like specific sound frequencies could theoretically impact cancer cell viability, proliferation, or sensitivity/resistance to radiation. For example, altered chloride channel function is implicated in cancer progression and treatment response, making interventions that influence chloride dynamics potentially relevant. Therefore, the preliminary observation of enhanced salt reduction at 116 Hz not only suggests a potential method to improve the desalination process but also opens speculative avenues linking physical phenomena (sound frequencies), ion dynamics, and potential biological effects with potential relevance for cancer research and radiation oncology, drawing parallels with traditional practices associated with this frequency.
The process of using steamed soybeans to adsorb salt from seawater yields a valuable byproduct: soybeans enriched with minerals from the seawater. The potential exists to utilize these salt-containing soybeans as a primary ingredient for making miso. Traditional miso production involves fermenting soybeans with salt and koji (fermented rice or barley). By using soybeans that have already adsorbed salt from seawater, the need to add external salt during miso production could be reduced or potentially eliminated, thereby addressing the historical "salt problem" associated with miso consumption while retaining its established health benefits.
The significant findings from the large-scale epidemiological survey by Hirayama (1982), showing a 50% lower standardized mortality rate for stomach cancer among daily miso soup consumers, underscore the potent health-promoting properties of miso. These effects are attributed to the complex interplay of components in fermented soybeans, including peptides, amino acids, melanoidins, and beneficial microbes, which have demonstrated antioxidant, anti-inflammatory, and potentially anti-cancer activities. Furthermore, recent investigations show that pretreatment intake of soy food and miso soup is inversely associated with the risk of all-cause and stomach cancer death in stomach cancer patients, suggesting potential benefits for patient survival (Minami et al., 2020). It is also particularly relevant that established research highlights miso's potential in preventing various cancers and, significantly, in offering protection against radiation injury (Watanabe, 2013). Studies have shown that miso, especially with longer fermentation times, can increase crypt survival against radiation injury in mice, suggesting a potential radioprotective effect relevant to mitigating side effects of radiation therapy. Producing miso from seawater-treated soybeans could potentially leverage these benefits while offering a more mineral-rich profile, given the similarity in mineral composition between seawater and human body fluids, presenting a novel approach to delivering these potential health benefits.
This approach offers a compelling vision: transforming a readily available resource (seawater) into both potable water and a highly nutritious fermented food (miso) through a simple, potentially low-energy process inspired by traditional food preparation. The inherent robustness and adaptability of miso as a food source, even in extremely challenging environments, is highlighted by recent advancements in space exploration. A notable experiment successfully demonstrated the feasibility of food fermentation in space by producing traditional Japanese miso on the International Space Station (ISS) over a 30-day period (Coblenlz et al., 2025). This space-fermented miso was compared to earthbound controls using a comprehensive suite of analytical methods, including environmental metadata, shotgun metagenomics, whole-genome sequencing, untargeted metabolomics, colorimetry, and sensory analysis. The results confirmed that the space miso was recognizable as a fermented miso product, definitively showing that fermentation is possible in microgravity. While key microbiological and sensory differences were observed, suggesting distinctive features imparted by the space environment, the overall success underscores miso's resilience and potential utility. This successful production of miso in space further supports the idea of its potential global, and even extraterrestrial, relevance for nutrition and well-being, making the concept of producing it from locally available (seawater) resources on Earth particularly compelling.
The concept of using seawater-treated soybeans for miso production and drinking water represents a potential convergence of environmental sustainability, nutritional science, and traditional food culture that could instigate a significant shift in our societal values (Hiratsuka et al., 2023). This shift could move from a focus solely on "Truth, Goodness, and Beauty" in abstract terms towards a more integrated understanding of "Benefit, Goodness, and Beauty," where scientific understanding (Truth) is applied to create tangible advantages for human health and the environment (Benefit), aligning with aesthetic and ethical considerations (Goodness and Beauty).
While the experiments presented here are preliminary and require further scientific validation with controlled conditions, larger volumes, and detailed chemical analysis of both the desalinated water and the resulting soybeans, they offer a compelling proof-of-concept. Further research is needed to optimize the salt adsorption process, characterize the mineral content of the treated soybeans, and conduct studies on the fermentation process and the nutritional and health properties of miso produced using this method. The intriguing observation regarding the 116 Hz frequency also warrants dedicated investigation to confirm the effect and explore potential mechanisms.
In conclusion, this work proposes a novel, bio-inspired approach to seawater desalination and food production using steamed soybeans. The preliminary experimental results on salt adsorption are promising and, combined with the established health benefits of miso and the intriguing preliminary observation regarding the 116 Hz frequency, suggest a potential pathway to address critical global challenges related to water scarcity and nutrition. Furthermore, this research explores novel avenues that, with further investigation, could potentially contribute to our understanding of dietary factors and non-thermal physical stimuli relevant to cancer prevention, supportive care in oncology, and modulating cellular responses relevant to radiation therapy. This concept warrants further comprehensive scientific investigation to unlock its full potential for human health and environmental sustainability.