ε-Polylysine hydrochloride's potential in reducing microbial contamination in food supplements.


Food supplements, commonly known as dietary supplements, are products intended to supplement the diet and provide essential nutrients or other bioactive compounds that may be lacking in one's daily intake. These supplements come in various forms, including capsules, tablets, powders, and liquids, and are consumed by millions of people worldwide to support overall health, well-being, and nutritional needs. However, the safety and efficacy of food supplements can be compromised by microbial contamination, which may occur during manufacturing, storage, or distribution processes. Contaminated supplements can harbor harmful microorganisms, such as bacteria, molds, and yeasts, posing risks of foodborne illness and adverse health effects for consumers.

ε-Polylysine hydrochloride, a cationic polypeptide derived from bacterial fermentation, has emerged as a promising antimicrobial agent for controlling microbial contamination in food supplements. This review provides a comprehensive overview of ε-Polylysine hydrochloride's potential in reducing microbial contamination in various types of food supplements, including its mechanisms of action, applications, and future research directions.

Mechanisms of ε-Polylysine Hydrochloride's Antimicrobial Activity:

ε-Polylysine hydrochloride exhibits potent antimicrobial activity against a wide range of microorganisms, including bacteria, molds, and yeasts. Its antimicrobial effects are attributed to several key mechanisms:

  1. Disruption of Cell Membranes: ε-Polylysine hydrochloride interacts with microbial cell membranes, leading to membrane destabilization, permeabilization, and leakage of intracellular contents. Its cationic nature enables it to bind to negatively charged components of microbial cell membranes, such as lipopolysaccharides and phospholipids, disrupting membrane integrity and inducing cell lysis.
  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 nucleic acid replication. By interfering with these enzymatic pathways, ε-Polylysine hydrochloride disrupts microbial metabolism and growth, ultimately leading to cell death.
  3. Prevention of Biofilm Formation: ε-Polylysine hydrochloride inhibits the formation of microbial biofilms, which are structured 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.

Applications of ε-Polylysine Hydrochloride in Food Supplements:

ε-Polylysine hydrochloride can be incorporated into food supplements through various formulations and applications to reduce microbial contamination and ensure product safety:

  1. Encapsulation: ε-Polylysine hydrochloride can be encapsulated within supplement capsules or tablets to provide sustained release of the antimicrobial agent and inhibit microbial growth within the supplement matrix.
  2. Powder Formulations: ε-Polylysine hydrochloride can be incorporated into powdered supplement formulations, such as protein powders, vitamin mixes, and botanical extracts, to prevent microbial contamination and extend shelf life.
  3. Liquid Formulations: ε-Polylysine hydrochloride can be added to liquid supplement formulations, such as tinctures, tonics, and elixirs, to inhibit microbial growth and maintain product stability during storage and distribution.
  4. Packaging Materials: ε-Polylysine hydrochloride can be incorporated into supplement packaging materials, such as sachets, blister packs, and bottles, to create active packaging systems that release antimicrobial agents and prevent microbial contamination during storage and handling.

Benefits of ε-Polylysine Hydrochloride in Food Supplements:

The use of ε-Polylysine hydrochloride in food supplements offers several potential benefits for manufacturers, distributors, and consumers:

  1. Enhanced Safety: ε-Polylysine hydrochloride effectively reduces microbial contamination in food supplements, minimizing the risk of foodborne illness and ensuring product safety for consumers.
  2. Extended Shelf Life: ε-Polylysine hydrochloride extends the shelf life of food supplements by inhibiting microbial growth, reducing spoilage, and maintaining product quality and efficacy over time.
  3. Preservation of Nutritional Integrity: ε-Polylysine hydrochloride preserves the nutritional integrity and bioavailability of active ingredients in food supplements by preventing microbial degradation and oxidation during storage and distribution.
  4. Regulatory Compliance: ε-Polylysine hydrochloride is Generally Recognized as Safe (GRAS) by regulatory authorities, such as the Food and Drug Administration (FDA) in the United States, making it suitable for use in food supplements and ensuring regulatory compliance.

Challenges and Future Directions:

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

  1. Formulation Optimization: Further research is needed to optimize the formulation, concentration, and application methods of ε-Polylysine hydrochloride for different types of food supplements, processing conditions, and storage environments to maximize its antimicrobial efficacy and minimize potential sensory changes.
  2. Stability and Compatibility: ε-Polylysine hydrochloride's stability and compatibility with other supplement ingredients, such as vitamins, minerals, and botanical extracts, should be evaluated to ensure product integrity and efficacy.
  3. Consumer Acceptance: Consumer perception and acceptance of ε-Polylysine hydrochloride-treated supplements 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 antimicrobial agent.
  4. Regulatory Considerations: The use of ε-Polylysine hydrochloride in food supplements may require regulatory approval from government agencies, such as the FDA or the European Food Safety Authority (EFSA), to ensure its safety and efficacy for human consumption. Manufacturers and distributors must comply with applicable regulations and labeling requirements when incorporating ε-Polylysine hydrochloride into food supplements, including dosage limits, allergen declarations, and storage instructions.


ε-Polylysine hydrochloride holds significant potential in reducing microbial contamination in food supplements, enhancing product safety, and extending shelf life. Its antimicrobial properties, natural origin, and compatibility with supplement formulations make it an attractive option for manufacturers seeking effective preservation solutions. By incorporating ε-Polylysine hydrochloride into supplement formulations and packaging materials, the industry can mitigate the risks of microbial contamination, protect consumer health, and ensure product quality and integrity.

Moving forward, continued research and development efforts are needed to optimize ε-Polylysine hydrochloride formulations, address regulatory requirements, and educate stakeholders about its benefits and applications in food supplements. Collaboration between industry, academia, and regulatory agencies can help advance the use of ε-Polylysine hydrochloride as a safe and effective antimicrobial agent, promoting innovation and sustainability in the supplement industry.

In conclusion, ε-Polylysine hydrochloride represents a promising tool for reducing microbial contamination in food supplements, contributing to improved food safety, consumer confidence, and public health outcomes. With ongoing innovation and collaboration, ε-Polylysine hydrochloride has the potential to become a valuable asset in the global effort to ensure the safety and integrity of dietary supplements for consumers worldwide.