Innovative applications of Nisin in the Food Industry

Nisin, also known as lactococcal bacteriocin, is a polypeptide antimicrobial substance produced by Streptococcus lactis. It exhibits strong inhibitory effects on spoilage bacteria and pathogenic bacteria, particularly Gram-positive bacteria, and is globally recognized as a safe natural biological food preservative and bacteriostatic agent. Below are some innovative application cases of Nisin in the food industry:

1. Dairy Products Field

1.1 Fresh Milk Preservation

Adding 0.03–0.05 g/kg of Nisin to fresh milk can inhibit heat-resistant bacteria that cause milk spoilage, extending the product’s shelf life by 2–3 times. For example, under a 45°C environment, the shelf life of low-fat milk, unsalted butter, non-fat milk, and flavored milk supplemented with Nisin can be extended to 6 weeks.

1.2 Anticorrosion of Canned Unsweetened Condensed Milk

Incorporating 0.08–0.1 g/kg of Nisin into canned unsweetened condensed milk not only inhibits the spore growth of heat-resistant spore-forming bacteria but also shortens the thermal processing time by 10 minutes, while ensuring the product’s quality and taste remain intact.

2. Meat Products Field

2.1 Sausage Anticorrosion

Adding Nisin to sausages can inhibit most Gram-positive bacteria without affecting the product’s color, aroma, or flavor. It also reduces the usage of nitrates or nitrites. For instance, in the production of shredded pork products, Nisin can replace potassium sorbate as a preservative, improving product quality and extending shelf life.

2.2 Quality Improvement of Flexible-Packaged Braised Chicken

Adding Nisin during the processing of flexible-packaged braised chicken can reduce sterilization intensity and enhance the eating quality of the product. When the sterilization temperature is lowered from 121°C to 105°C (with other process conditions unchanged), the shelf life can reach more than 6 months, and the taste is also improved.

3. Beverages and Brewed Wines Field

3.1 Fruit Juice Anticorrosion

Bacillus acidoterrestris often causes spoilage in fruit juices and fruit juice-based beverages. Adding 10–30 mg/L of Nisin to fruit juice and fruit juice products before pasteurization not only reduces thermal processing intensity but also prevents the growth of surviving Bacillus acidoterrestris spores, thus avoiding juice spoilage.

3.2 Fresh Beer Preservation

Leveraging Nisin’s property of not inhibiting yeast, adding it to fresh beer can prevent spoilage caused by lactic acid bacteria and extend the beer’s storage time.

4. Canned Food Field

4.1 Vegetable Can Anticorrosion

Adding 0.1 g/kg of Nisin to vegetable cans effectively inhibits the spoilage of heat-resistant bacteria and shortens thermal processing time. For example, when canned peas are stored at 55°C, spoilage occurs within 7 days without Nisin addition; with Nisin, the shelf life can be extended to up to 2 years.

4.2 Processing of Canned Rice Wine (Sake)

Adding Nisin to canned rice wine (sake) reduces thermal processing time by 90% without altering product quality, significantly improving production efficiency while preserving the taste and flavor of the sake.

5. Condiments Field

Adding 0.05–0.2 g/kg of Nisin to condiments such as vinegar, soy sauce, and salad dressing can effectively inhibit the growth of lactic acid bacteria and spores. This reduces the spoilage risk of low-fat and low-salt condiment products, extends their shelf life by up to 4 times, and maintains their original flavor and quality.

6. Liquid Eggs and Egg-Containing Processed Products Field

Adding 0.05–0.1 g/kg of Nisin to egg products effectively inhibits heat-resistant spore-forming bacteria such as Bacillus spp. It extends the shelf life of liquid eggs from the original 7 days to 1 month, providing more time for the processing and sales of egg products.

7. Seafood Products (e.g., Fish and Shellfish) Field

Adding 0.1–0.15 g/kg of Nisin to seafood products like fish and shellfish inhibits Gram-positive bacteria and extends shelf life. For example, in cold-ready seafood products, Nisin can effectively control bacterial counts and ensure food safety.

8. Hermetically Packaged Products Subjected to Low-Temperature Thermal Processing

For hermetically packaged products (e.g., protein milk, fruit juice, pudding, tea, and beverages) that undergo low-temperature thermal processing, adding 0.1–0.2 g/kg of Nisin solves the problem of short shelf life caused by the inability of low-temperature thermal processing to kill heat-resistant spores. This extends the shelf life while ensuring product quality.