Nisin Powder Preservative

Nisin (lactic streptococcus peptide) powder is a polypeptide substance produced by Lactococcus lactis, with significant preservative properties. It effectively inhibits many Gram-positive bacteria responsible for food spoilage, such as Lactobacillus, Streptococcus, Micrococcus, Staphylococcus, and Listeria. Notably, it has strong inhibitory effects on spore-forming bacteria such as Bacillus and Clostridium.

Typically, spore-forming bacteria have strong heat resistance, with some spores surviving even ultra-high temperature sterilization. However, adding 0.03-0.05g/kg of nisin to food can effectively inhibit the germination and proliferation of Bacillus and Clostridium spores, thereby extending the shelf life of the food.

The preservative mechanism of nisin differs from other preservatives. It does not kill the spores directly but inhibits the germination process before spore swelling occurs. Thus, nisin can provide excellent preservation in heat-processed canned foods, significantly saving energy.

Additionally, nisin can be combined with chemical preservatives to reduce their required amounts. It can also work with chelating agents like EDTA or citric acid, making some bacteria more sensitive to nisin.

After consumption, nisin rapidly hydrolyzes into amino acids under physiological pH conditions and the action of α-chymotrypsin. It does not alter the normal gut flora nor cause resistance issues related to other antibiotics, and it does not induce cross-resistance with other antibiotics. Therefore, nisin is an efficient, non-toxic, and safe natural food preservative.

Nisin is mainly used for preserving high-protein foods such as meat and soy products. However, it may not be as effective in low-protein foods and could even be utilized by microorganisms as a nitrogen source. Therefore, when using nisin for food preservation, it is essential to select and adjust according to the type and characteristics of the food.