ε-Polylysine hydrochloride's efficacy in controlling microbial contamination in seafood.


Seafood is a valuable source of protein, omega-3 fatty acids, vitamins, and minerals, enjoyed by consumers worldwide. However, its high moisture content, neutral pH, and nutrient-rich composition make seafood highly susceptible to microbial contamination, leading to spoilage, foodborne illnesses, and economic losses. Traditional methods of seafood preservation, such as chilling, freezing, and drying, are effective to a certain extent but may not provide sufficient protection against microbial growth and spoilage. As such, there is a growing need for alternative antimicrobial strategies to enhance the safety and shelf life of seafood products. ε-Polylysine hydrochloride, a cationic polypeptide derived from bacterial fermentation, has emerged as a promising antimicrobial agent for controlling microbial contamination in seafood. This review provides an in-depth analysis of ε-polylysine hydrochloride's efficacy in seafood preservation, including its mechanisms of action, applications, and potential benefits for the seafood industry.

Mechanisms of ε-Polylysine Hydrochloride's Antimicrobial Activity:

ε-Polylysine hydrochloride exerts its antimicrobial activity through multiple mechanisms, including:

  1. Disruption of Cell Membranes: ε-Polylysine hydrochloride interacts with microbial cell membranes, leading to membrane destabilization, leakage of cellular contents, and ultimately, cell death. Its cationic nature enables it to bind to negatively charged components of bacterial cell membranes, such as lipopolysaccharides and phospholipids, disrupting membrane integrity and permeability.
  2. Inhibition of Enzymatic Activity: ε-Polylysine hydrochloride inhibits the activity of microbial enzymes involved in essential cellular processes, such as cell wall synthesis, protein synthesis, and DNA replication. By interfering with these enzymatic pathways, ε-polylysine hydrochloride disrupts microbial metabolism and growth.
  3. Disruption of Biofilm Formation: ε-Polylysine hydrochloride inhibits the formation of microbial biofilms, which are complex communities of microorganisms encased in an extracellular matrix. By preventing biofilm formation, ε-polylysine hydrochloride reduces microbial attachment to surfaces and inhibits the development of persistent microbial populations.
  4. Synergistic Interactions: ε-Polylysine hydrochloride exhibits synergistic interactions with other antimicrobial agents, such as organic acids, chelating agents, and preservatives, enhancing their efficacy against a wide range of microorganisms.

Applications of ε-Polylysine Hydrochloride in Seafood Preservation:

ε-Polylysine hydrochloride has been widely studied for its efficacy in controlling microbial contamination in various seafood products, including:

  1. Fish Fillets and Seafood Products: ε-Polylysine hydrochloride can be applied topically or incorporated into seafood coatings, films, or dips to inhibit microbial growth, reduce spoilage, and extend the shelf life of fish fillets, shrimp, scallops, and other seafood products.
  2. Seafood Processing Water: ε-Polylysine hydrochloride can be added to seafood processing water as a disinfectant or antimicrobial agent to reduce microbial contamination and cross-contamination during processing, washing, and chilling operations.
  3. Seafood Packaging Materials: ε-Polylysine hydrochloride can be incorporated into seafood packaging materials, such as films, wraps, and trays, to create active packaging systems that release antimicrobial agents and inhibit microbial growth during storage and distribution.
  4. Seafood Preservation Solutions: ε-Polylysine hydrochloride can be used as an ingredient in seafood preservation solutions, brines, or marinades to enhance microbial safety, texture, and sensory attributes while maintaining product quality and freshness.

Benefits of ε-Polylysine Hydrochloride in Seafood Preservation:

The use of ε-Polylysine hydrochloride in seafood preservation offers several potential benefits, including:

  1. Improved Food Safety: ε-Polylysine hydrochloride effectively inhibits the growth of spoilage microorganisms and pathogens, reducing the risk of foodborne illnesses and microbial contamination in seafood products.
  2. Extended Shelf Life: ε-Polylysine hydrochloride extends the shelf life of seafood products by inhibiting microbial spoilage, reducing off-flavors and odors, and maintaining product quality and freshness.
  3. Enhanced Quality: ε-Polylysine hydrochloride preserves the sensory attributes, texture, and appearance of seafood products by minimizing microbial spoilage and oxidative deterioration during storage and distribution.
  4. Reduced Chemical Additives: ε-Polylysine hydrochloride offers a natural alternative to chemical preservatives, such as sulfites and sorbates, reducing the reliance on synthetic additives and addressing consumer preferences for clean-label products.

Challenges and Future Directions:

While ε-Polylysine hydrochloride shows promise as an effective antimicrobial agent for seafood preservation, several challenges and considerations should be addressed:

  1. Regulatory Approval: The use of ε-Polylysine hydrochloride in seafood products may require regulatory approval from government agencies, such as the Food and Drug Administration (FDA) or the European Food Safety Authority (EFSA), to ensure its safety and efficacy for human consumption.
  2. Optimization of Formulations: Further research is needed to optimize the formulation, concentration, and application methods of ε-Polylysine hydrochloride for different seafood matrices, processing conditions, and storage environments to maximize its antimicrobial efficacy and minimize potential sensory changes.
  3. Consumer Acceptance: Consumer perception and acceptance of ε-Polylysine hydrochloride-treated seafood products may vary depending on factors such as labeling, transparency, and familiarity with the ingredient. Education and communication efforts are essential to address consumer concerns and promote the adoption of ε-Polylysine hydrochloride as a safe and effective seafood preservative.
  4. Sustainability Considerations: The production and use of ε-Polylysine hydrochloride should be evaluated for their environmental impact, resource efficiency, and sustainability compared to conventional preservation methods. Life cycle assessments and eco-design strategies can help identify opportunities to minimize environmental footprint and promote sustainable practices in the seafood industry.


ε-Polylysine hydrochloride holds significant promise as a natural antimicrobial agent for controlling microbial contamination in seafood products. Its broad-spectrum activity, natural origin, and potential to extend shelf life and enhance food safety make it a valuable tool for the seafood industry. Continued research and development efforts are needed to optimize ε-Polylysine hydrochloride formulations, validate its efficacy under different conditions, and address regulatory, consumer, and sustainability considerations. By leveraging the antimicrobial properties of ε-Polylysine hydrochloride, the seafood industry can improve the safety, quality, and sustainability of seafood products, meeting the growing demand for safe and nutritious food options.

In conclusion, ε-Polylysine hydrochloride presents a promising solution for controlling microbial contamination in seafood. Its antimicrobial properties, natural origin, and potential for extending shelf life make it an attractive alternative to traditional chemical preservatives. By incorporating ε-Polylysine hydrochloride into seafood processing and packaging practices, the industry can enhance food safety, reduce food waste, and meet consumer preferences for clean-label products. However, further research is needed to optimize its use, address regulatory requirements, and ensure consumer acceptance. With continued innovation and collaboration, ε-Polylysine hydrochloride has the potential to play a significant role in shaping the future of seafood preservation and food safety.