ε-Polylysine

Overview
ε-Polylysine is a high-efficiency antimicrobial agent or preservative. It is produced from a fermentation process using Streptomyces albulus under aerobic conditions. It has obvious inhibition to gram-positive bacteria and Gram-negative bacteria, yeast, mould, virus. In addition, it also has excellent safety, therefore it is widely used as an antistaling agent.

Molecular Structure
ε-Polylysine is a homopolymer of L-lysine, one of the essential amino acids. It is linked by peptide bond formed with α-carboxyl of L-lysine and ε-azyl from other L-lysine. The chemical formula for ε-polylysine is shown in figure 1.


Figure1. chemical formula of ε-Polylysine

Physicochemical Property
ε-Polylysine is pale yellow powder, strong hygroscopicity, slightly bitter; Easily soluble in water and hydrochloric acid, Not in organic solvents such as alcohol, ether. It’s isoelectric point is 9.0, specific rotation [α] is ＋57.1°(c=1, H2O), [α] is ＋39.9°(c=1, 5, mol/L HCI)

Biological Property
1. Broad antibacterial spectrum: It has obvious inhibition to gram-positive bacteria and Gram-negative bacteria, yeast, mould, virus and many other microorganism.
2. Good thermal stability: Below high temperature（80℃-60 min、100℃-30 min and 120℃-20 min）, it does not decompose, not inactivation, suitable for cooked food.
3. Good water-solubility: good water-solubility, it can spread evenly in food, effect good ; Colorless, odorless and nature, do not affect food flavor.
4.Widely PH range: broad antibacterial spectrum, the range of PH is between 2 and 9, to supplement the weekness that most common preservative poorly effects in neutral and alkaline conditions.
5. Strong Blends: it have synergistic effect when blending with potassium sorbet, citric acid, malic acid, glycine and Nisin and senior fat crosslinker.
6. High safety: After eating, it is not accumulated inside human bodies, partly break down into essential amino acid lysine for human body, L –lysine, Non-toxic, known as the "pharmaceutical &nutrient preservatives"
7. Health function: Recent studies show that ε-Polylysine can inhibit the enzyme activity and the fat absorption in the small intestine ester, has curative effect against with obesity.

Applications
Currently, ε-Polylysine is widely used in food preservatives, such as: cake, pastry, snack foods, butter, salad, sauce, beverage, wine, meat product, can, etc.The dosage In different types of food can be referenced in table 1.

Kinds of food		recommended usage
Cooked product	sausages	100—250mg/kg
	ham	100—250mg/kg
Fresh meat	Cold fresh	200—400mg/kg（surface treatment）
	Frozen meat	200—400mg/kg（surface treatment）
Beverage	Pure water	50—100mg/L
	Fruit drink	100—200mg/L
	Protein beverage	100—200mg/L
	Water-based seasonings drinks	100—200mg/L
	tea、coffee、herbal drink	100—200mg/L
Seafood	Fresh aquatic product	200—400mg/kg（surface treatment）
	Frozen seafood and product	200—400mg/kg（surface treatment）
	Prefabrication of aquatic products	150—300mg/kg
	Cooked aquatic products	150—300mg/kg
Bakery	bread	100—200mg/kg
	Chinese pastry	150—250mg/kg
	cake	150—250mg/kg
Milk and dairy product	Pure milk	100—200mg/L
	Single cream	150—250mg/kg
	cheese	150—250mg/kg

Usage
You may confect the 5-10% ε-Polylysine solution with cold boiled water or distilled water, then put it into the food and mix fully, Should adopt grading expanding method to add, in order to achieve the purpose of mixing. If it is used together with other food preservatives, can attain better effect.

Storage
Seal,away from direct sunlight, under 15℃. Shelf life is 2 years.