PROTAMINE

1.Chemical Properties

White to pale yellow powder with a distinctive odor. Heat-resistant, retaining antibacterial activity after 90 minutes at 210°C, making it suitable for use with heating to achieve preservative effects. Minimum inhibitory concentration in alkaline media ranges from 70 to 400 mg/ml. Exhibits antibacterial activity against heat-resistant spore-forming bacteria, lactic acid bacteria, Staphylococcus aureus, molds, and Gram-negative bacteria under neutral to alkaline conditions, with peak efficacy at pH 7–9. Heat-stable (120°C for 30 minutes). Combining it with glycine, acetic acid, salts, or brewed vinegar, along with alkaline salts, enhances its antibacterial effect. It improves elasticity in fish paste products. When used with seasonings, it enhances umami flavor. However, its efficacy decreases when combined with proteins, salts, or acidic polysaccharides, forming insoluble compounds. Soluble in water, slightly soluble in aqueous ethanol, insoluble in ethanol.

2.Applications

Preservative. Used in Japan for starchy foods like rice, Chinese noodles, fried noodles, steamed buns, bread, and dumplings, as well as fish paste products and seasonings. Formulated with sodium acetate, glycine, ethanol, etc., for cakes, pastes, and similar foods.

3.Production Methods

Derived from nucleic acids and alkaline proteins in the milt of mature male fish such as salmon (Chinook salmon; Oncorhynchus keta), pink salmon (Oncorhynchus gorbuscha), sockeye salmon (Oncorhynchus nerka), herring, trout, mackerel, and bonito. These components are decomposed under acidic conditions and then neutralized.