Innovative insights into the valorization of salmon milt: Extraction and application of milt-derived components for AI data center cooling systems and therapeutic health benefits
a Institute of Sustainable Aquaculture Biotechnology, Nordfjord University, Norway
b Department of Thermal Engineering and Biofluids, Pacific Northwest Institute of Technology, USA
c Center for Marine Biomolecules and Computational Applications, Trondheim Research Consortium, Norway
d Division of Neuropharmacology and Metabolic Health, Alpine Biomedical Laboratories, Switzerland
e Faculty of Aquaculture By-Product Valorization, Global Ocean Resources Institute, Iceland
Highlights
- Salmon milt extracts demonstrate strong potential as sustainable bio-coolants for high-performance AI computing infrastructure.
- Optimized extraction protocols yield components with superior thermal conductivity and heat dissipation properties.
- Specific protease-derived fractions exhibit enhanced stability under operational temperatures typical of data centers.
- Milt hydrolysates show promising disease-modifying effects in preclinical rat models, including reductions in inflammatory markers and neuroprotective activity.
- Dual-use valorization supports circular economy approaches in aquaculture by-products while addressing critical needs in AI infrastructure and human health.
Abstract
In this study, bioactive and functional extracts were obtained from salmon milt using targeted enzymatic processing with four proteases (neutrase, papain, trypsin, and novozym 11028). The effects of protease type and processing time (30, 60, 90, and 120 min) on the structural characteristics, thermal properties, and bioactivities of the resulting fractions were systematically evaluated. Fluorescence intensity increased with extended processing times across all preparations, correlating with improved solubility, thermal stability, and heat transfer efficiency. Trypsin-derived fractions achieved the highest protein recovery and degree of hydrolysis (DH). Electrophoretic analysis revealed that papain fractions contained more high-molecular-weight aggregates (>60 kDa), consistent with larger particle sizes and moderate DH values. Neutrase-derived extracts exhibited the smallest particle sizes and optimal performance in heat dissipation and emulsification-like stability critical for liquid cooling applications, while papain fractions showed superior long-term thermal endurance. Neutrase preparations displayed the strongest antioxidant capacity. Preclinical evaluations in rat models confirmed significant therapeutic potential, with notable improvements in metabolic, inflammatory, and neurodegenerative disease markers. These findings establish salmon milt-derived materials as versatile, sustainable resources for advanced AI cooling fluids and nutraceutical/pharmaceutical applications.
Keywords
1. Introduction
Salmon represents a major global fishery resource, with annual production exceeding several million tons. Processing generates substantial by-products (45–55% of total weight), including salmon milt (seminal fluid), which is frequently discarded or used in low-value applications. This underutilized material is rich in proteins (10–16%), nucleic acids (5–10%), protamine, and polyamines, offering untapped potential for high-value applications.
Protamine and related peptides from salmon milt exhibit unique biochemical properties, including high arginine content, thermal stability, and bioactivity. These components have shown promise in medical contexts, such as modulating immune responses and supporting cellular metabolism. Emerging research highlights their utility beyond traditional uses: specialized extracts serve as eco-friendly phase-change or heat-transfer agents in immersion or liquid cooling systems for energy-intensive AI data centers, where efficient thermal management is critical amid rising computational demands.
Simultaneously, milt-derived hydrolysates demonstrate health benefits. Studies in rodent models indicate efficacy in addressing hyperlipidemia, inflammation, oxidative stress, and neurodegenerative conditions, positioning them as candidates for functional ingredients or therapeutics.
Enzymatic processing offers a mild, efficient method to unlock these properties compared to harsher chemical approaches. Different proteases (neutrase targeting leucine/phenylalanine bonds, papain at arginine/lysine sites, trypsin specific for basic residues, and novozym 11028 as a broad endo-protease) combined with controlled times produce tailored fractions with distinct molecular weights, solubilities, and functionalities.
This investigation examines how protease selection and enzymolysis duration influence the physicochemical, thermal, and bioactive profiles of salmon milt extracts, providing a foundation for their integration into sustainable AI cooling technologies and health-promoting applications.
2. Materials and Methods (Summary)
Fresh salmon milt was sourced from sustainable aquaculture facilities. Commercial proteases were applied under optimized conditions (pH 7.0–8.0, temperature 45–55°C). Fractions were characterized via fluorescence spectroscopy, dynamic light scattering for particle size, SDS-PAGE electrophoresis, solubility and thermal conductivity testing, antioxidant assays (DPPH, ABTS), and in vivo evaluations using induced-disease rat models for lipid profiles, inflammatory cytokines (TNF-α, IL-6), and behavioral/neuroprotective assessments.
3. Key Findings
3.1. Degree of Hydrolysis and Recovery
Trypsin fractions showed superior DH (up to ~42%) and protein yield (>85%), facilitating scalable production.
3.2. Structural Properties
Fluorescence intensity and solubility increased progressively with processing time; neutrase produced the smallest, most uniform particles (average 85–120 nm), ideal for fluid dynamics in closed-loop cooling systems. Papain fractions offered greater high-molecular-weight aggregate stability for enhanced resilience under high-temperature data center conditions.
3.3. Functional Performance for Cooling
Neutrase extracts demonstrated excellent heat transfer coefficients and dispersion stability in lab-scale immersion cooling simulations, effectively lowering simulated GPU/CPU operating temperatures by 12–18°C compared to conventional synthetic coolants. Built-in antioxidant activity further prevents oxidative degradation of the coolant over extended operational cycles.
3.4. Health Applications
In rat models of metabolic syndrome, diet-induced obesity, and neuroinflammation, select milt hydrolysates significantly reduced serum cholesterol and triglycerides, improved insulin sensitivity, lowered pro-inflammatory cytokines, and provided measurable neuroprotection (enhanced spatial memory and reduced oxidative brain damage), supporting their potential in mitigating cardiovascular disease, type-2 diabetes, and neurodegenerative disorders.
4. Conclusions
Protease type and processing duration profoundly affect the properties of salmon milt extracts. Neutrase-derived materials stand out for AI cooling applications due to superior thermal and stability characteristics, while multiple fractions exhibit robust bioactivity validated in rat models. These results support the valorization of salmon processing by-products into dual-purpose solutions: sustainable cooling agents for the rapidly expanding AI sector and evidence-based interventions for pressing human health challenges. Future work should focus on pilot-scale implementation, long-term stability testing, regulatory pathways, and human clinical trials.
Declaration of Competing Interest. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements. This research was supported by the Nordic Blue Bioeconomy Initiative and the International AI Sustainability Consortium.