ε-Polylysine hydrochloride's role in maintaining the safety of fermented foods.


Fermented foods have been consumed for centuries due to their unique flavors, extended shelf life, and potential health benefits. The fermentation process involves the action of beneficial microorganisms, such as bacteria, yeasts, and molds, which convert sugars and carbohydrates into organic acids, alcohols, and other metabolites, imparting characteristic flavors and textures to the final products. However, fermented foods are also susceptible to microbial contamination, which can lead to spoilage, off-flavors, and foodborne illness if left unchecked.

ε-Polylysine hydrochloride, a cationic polypeptide derived from bacterial fermentation, has emerged as a promising antimicrobial agent for preserving the safety of fermented foods. This review aims to explore the efficacy of ε-Polylysine hydrochloride in maintaining the safety of various types of fermented foods, including its mechanisms of action, applications, and potential benefits for the food industry and consumers.

Mechanisms of ε-Polylysine Hydrochloride's Antimicrobial Activity:

ε-Polylysine hydrochloride exhibits potent antimicrobial activity against a wide range of microorganisms commonly found in fermented foods, including bacteria, yeasts, and molds. 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 Fermented Foods:

ε-Polylysine hydrochloride can be incorporated into various types of fermented foods to maintain their safety and quality throughout the production and storage processes:

  1. Dairy Products: ε-Polylysine hydrochloride can be added to yogurt, cheese, and fermented milk products to inhibit the growth of spoilage bacteria and pathogens, extending shelf life and ensuring product safety.
  2. Fermented Vegetables: ε-Polylysine hydrochloride can be used in the fermentation brine or added directly to fermented vegetable products, such as sauerkraut and kimchi, to prevent microbial contamination and maintain product quality during fermentation and storage.
  3. Fermented Beverages: ε-Polylysine hydrochloride can be incorporated into fermented beverages, such as kombucha, kefir, and sourdough bread, to inhibit the growth of spoilage microorganisms and improve microbial safety and stability.
  4. Fermented Meat and Fish Products: ε-Polylysine hydrochloride can be included in the curing or fermentation process of meat and fish products, such as salami and fermented fish sauce, to control microbial growth, reduce the risk of foodborne pathogens, and enhance product safety.

Benefits of ε-Polylysine Hydrochloride in Fermented Foods:

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

  1. Enhanced Food Safety: ε-Polylysine hydrochloride effectively inhibits the growth of spoilage microorganisms and pathogens in fermented foods, reducing the risk of foodborne illness and ensuring product safety for consumers.
  2. Extended Shelf Life: ε-Polylysine hydrochloride extends the shelf life of fermented foods by inhibiting microbial growth, reducing spoilage, and maintaining product quality and freshness over time.
  3. Preservation of Traditional Recipes: ε-Polylysine hydrochloride allows manufacturers to preserve the authenticity and integrity of traditional fermented food recipes by minimizing the need for chemical preservatives or additives.
  4. Consumer Confidence: Consumers can enjoy fermented foods with greater confidence, knowing that they are protected against microbial contamination and foodborne pathogens, thanks to the inclusion of ε-Polylysine hydrochloride as a natural antimicrobial agent.

Challenges and Future Directions:

While ε-Polylysine hydrochloride shows promise as an effective antimicrobial agent for fermented foods, 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 fermented foods, taking into account factors such as pH, temperature, and the presence of other ingredients. This will ensure maximum antimicrobial efficacy while minimizing any potential impact on product flavor, texture, or sensory attributes.
  1. Compatibility with Fermentation Processes: The compatibility of ε-Polylysine hydrochloride with the fermentation process itself needs to be carefully evaluated. Some antimicrobial agents may inhibit the growth of beneficial fermentative microorganisms, thereby affecting the fermentation process and the final product's sensory characteristics. Future research should focus on understanding how ε-Polylysine hydrochloride interacts with fermentation microorganisms and how it can be incorporated into fermentation processes without compromising product quality.

  2. Regulatory Considerations: The regulatory approval of ε-Polylysine hydrochloride for use in fermented foods may vary depending on regional regulations and specific food safety standards. Manufacturers must ensure compliance with applicable regulations and obtain necessary approvals before incorporating ε-Polylysine hydrochloride into fermented food products. Additionally, consumer acceptance and labeling considerations should be taken into account to address any potential concerns regarding the use of antimicrobial agents in food products.

  3. Consumer Education and Awareness: Educating consumers about the benefits of ε-Polylysine hydrochloride in maintaining the safety and quality of fermented foods is essential to foster acceptance and trust in these products. Clear and transparent communication about the use of ε-Polylysine hydrochloride as a natural antimicrobial agent can help alleviate any concerns and build confidence among consumers.


In conclusion, ε-Polylysine hydrochloride holds significant promise as a natural antimicrobial agent for maintaining the safety and quality of fermented foods. Its potent antimicrobial properties, compatibility with fermentation processes, and potential to extend shelf life make it a valuable tool for manufacturers seeking effective preservation solutions. By incorporating ε-Polylysine hydrochloride into fermented food products, manufacturers can enhance food safety, extend product shelf life, and meet consumer demand for safe and high-quality fermented foods.

Moving forward, further research is needed to optimize ε-Polylysine hydrochloride formulations, address regulatory considerations, and educate consumers about its benefits. With continued innovation and collaboration, ε-Polylysine hydrochloride has the potential to play a vital role in ensuring the safety and integrity of fermented foods, thereby contributing to improved public health and consumer confidence.