Epsilon-Polylysine (Natural Preservative), Feed/とは？用途・使用量・代替品・規格

ε-Polylysine, English name is ε-Polylysine, also known as ε-PL, is a natural cationic polypeptide produced by microbial fermentation, generally composed of 25 to 35 L-lysine residues connected by amide bonds formed through the α-carboxyl group and the ε-amino group, and is the only naturally occurring homopolymeric amino acid with antibacterial properties. It has broad application value in the global food, pharmaceutical, cosmetic, and feed industries. Its molecular formula is H[C6H12N2O]n•H2O (n=25–35), molecular weight is typically between 3500 and 5000, and CAS number is 28211–04–3. As an emerging natural biological preservative, ε-polylysine has rapidly gained prominence in the food safety sector and is recognized as a green, highly effective product that effectively replaces traditional chemical preservatives. In terms of chemical structure, ε-polylysine belongs to the category of polycationic polypeptides, rich in positive charges. This unique cationic property allows it to electrostatically adsorb to the surface of negatively charged microbial cell membranes, destroying membrane integrity through physical disruption, causing leakage of microbial cell contents and subsequent cell death. This physical disruption mechanism gives ε-polylysine an extremely broad antibacterial spectrum and hardly induces microbial resistance. ε-Polylysine typically appears as a white to light yellow powder, is highly hygroscopic, and has a slight bitter taste. Its metabolic product in the human body is L-lysine, which can be completely digested and absorbed by the human body, making it safe and non-toxic.

ε-Polylysine is recognized as a star molecule among natural green preservatives, occupying a rapidly rising core position in the global food industry and biotechnology fields. Its most outstanding advantages lie in its excellent broad-spectrum antibacterial activity, outstanding thermal stability, safety surpassing traditional preservatives, unique multi-target antibacterial mechanism, and the nutritional value from its hydrolysis products. 1 Broad-Spectrum and Highly Effective Antibacterial Activity: ε-Polylysine exhibits excellent inhibitory effects against Gram-positive bacteria, Gram-negative bacteria, yeasts, and molds. It is particularly effective against Gram-negative bacteria such as Escherichia coli and Salmonella, which are difficult to inhibit with chemical preservatives. It also inhibits heat-resistant Bacillus spores and some viruses. Its antibacterial spectrum is the broadest among all natural food preservatives. 2 Excellent Thermal Stability: ε-Polylysine remains stable even after heating at 120°C for 20 minutes, withstanding food thermal processing such as UHT ultra-high-temperature instantaneous sterilization and high-pressure sterilization. This allows it to be flexibly incorporated throughout the entire thermal processing of products, maintaining its antibacterial effect whether added before, during, or after processing. 3 High Safety and Nutritional Properties: ε-Polylysine can be broken down in the human body into L-lysine, one of the eight essential amino acids for the human body. It is a nutritional antibacterial agent with safety far exceeding that of chemical preservatives. Its acute oral toxicity is 5g/kg, classifying it as practically non-toxic. It has been approved as a food additive in multiple countries including Japan, the United States, South Korea, and China. 4 Unique Physical Mechanism of Action: Carrying a large number of positive charges, ε-polylysine electrostatically adsorbs to the negatively charged cell membranes of microorganisms, causing microbial cell death through physical disruption. This non-specific mechanism does not rely on specific biochemical targets and hardly induces microbial resistance. This is a significant advantage that traditional antibiotics and chemical preservatives cannot match. 5 Wide pH Adaptability: Within the broad range of pH 3 to 9, ε-polylysine maintains strong antibacterial activity. Whether in acidic products (such as beverages and jams) or neutral products (such as rice and meat products), it exerts stable preservative effects. 6 Synergistic Enhancement: When used in combination with organic acids, glycine, alcohol, fatty acid glycerides, and other substances, ε-polylysine exhibits significant synergistic effects, further reducing required dosages and expanding application scenarios.