The application advantages of Nisin in green food production

Nisin offers significant application advantages in green food production, with its core strengths lying in its natural origin, high-efficiency antibacterial activity, safety (non-toxicity), and easy degradability. It can replace some chemical preservatives, aligning with the core requirements of green food—"no chemical residues, environmental friendliness, and health protection"—and is widely used in meat products, dairy products, fruit and vegetable products, and other fields.

I. Core Advantages: Aligning with Green Food’s Core Demands

Nisin’s properties are highly compatible with green food production standards, addressing the safety and environmental pain points of traditional chemical preservatives at the source.

(I) Natural Origin: Meeting the "Natural Attribute" Requirement of Green Food

Nisin is a natural antimicrobial peptide produced by the fermentation of lactic acid bacteria (strains of the genus Streptococcus lactis), not a chemically synthesized substance. Its production relies on microbial fermentation (e.g., using Streptococcus lactis to ferment milk or glucose media) with no chemical synthesis steps, complying with the green food standard of "prioritizing natural raw materials and processes."

Compared with chemical preservatives (e.g., sodium benzoate, potassium sorbate), Nisin eliminates concerns about "byproduct residues from chemical synthesis." Its fermentation raw materials (e.g., milk, sucrose) are mostly food-grade, and the production process is environmentally friendly, with no toxic wastewater or exhaust emissions.

(II) High-Efficiency Antibacterial Activity: Targeted Inhibition of Harmful Bacteria to Protect Food Quality

Nisin exerts strong inhibitory effects on Gram-positive bacteria—common spoilage and pathogenic bacteria in green food (e.g., Staphylococcus aureus, Listeria monocytogenes, Clostridium botulinum)—with a unique and efficient antibacterial mechanism:

Mechanism of action: It disrupts the integrity of bacterial cell membranes, forming transmembrane pores that cause the leakage of intracellular substances (e.g., potassium ions, amino acids), ultimately leading to bacterial death. Unlike antibiotics, it rarely induces bacterial resistance.

Antibacterial advantages: Even at low concentrations (typically 0.01%–0.05 g/kg), it significantly extends food shelf life. For example, adding Nisin to low-temperature meat products can extend the shelf life from 15 days to 30 days without affecting the food’s flavor or nutritional components (e.g., proteins, vitamins).

(III) Safety and Non-Toxicity: No Residues, No Health Risks

Nisin’s safety has been certified by global authoritative institutions (e.g., JECFA, FDA, China CFSA), making it the only antimicrobial peptide currently permitted for food use. Its core safety features include:

High human tolerance: The human digestive tract contains Nisin-degrading enzymes (e.g., trypsin), which rapidly break it down into amino acids. It is not absorbed by the intestines, does not react with human cells, and has no restricted acceptable daily intake (ADI) (conclusion from JECFA), with no cumulative toxicity even with long-term consumption.

No chemical residues: Nisin degrades naturally during food processing or storage, and its degradation products are amino acids—eliminating "health risks from chemical preservative residues" (e.g., liver damage potentially caused by excessive sodium benzoate)—and meeting the "no chemical residues" testing standard for green food.

(IV) Environmental Friendliness: Easy Degradation, No Ecological Burden

As a natural polypeptide, Nisin is rapidly degraded by microorganisms (e.g., protease-producing bacteria in soil) in the natural environment. Its degradation cycle is typically <7 days, and it eventually decomposes into carbon dioxide, water, and amino acids. It does not accumulate in soil or water bodies, nor does it harm ecosystems (e.g., aquatic organisms, soil microorganisms).

Compared with chemical preservatives (e.g., sodium dehydroacetate, which has a degradation cycle of several months in the environment), Nisin reduces pollution from food processing wastewater and discarded food, complying with the green food requirement of "environmental friendliness throughout the life cycle."

II. Typical Application Scenarios: Covering Major Green Food Categories

Nisin’s antibacterial properties adapt to the processing and storage needs of different green foods. It can replace chemical preservatives in multiple categories, enhancing the products’ green attributes.

(I) Meat Products: Extending Shelf Life and Replacing Nitrite (in Some Scenarios)

Green meat products (e.g., low-temperature ham, sausages, cured meat) are prone to contamination by Gram-positive bacteria (e.g., Listeria monocytogenes). Traditional processes often use nitrite (for color retention and preservation), but nitrite may be converted into the carcinogen nitrosamine.

Nisin application: Adding 0.02%–0.03 g/kg Nisin to low-temperature meat products can synergize with low-temperature sterilization (e.g., pasteurization at 60–70°C) to significantly inhibit pathogenic bacteria such as Listeria monocytogenes. It also reduces nitrite addition (from 50 mg/kg to <20 mg/kg), retaining product color while lowering the risk of nitrosamine formation—aligning with the green meat product requirements of "low nitrite and no chemical preservative residues."

(II) Dairy Products: Inhibiting Heat-Resistant Bacteria to Ensure the Safety of Low-Temperature Dairy Products

Green dairy products (e.g., fresh milk, yogurt, cheese) are often spoiled by heat-resistant Gram-positive bacteria (e.g., Bacillus cereus, mutant strains of Streptococcus thermophilus), which cannot be completely eliminated by conventional low-temperature sterilization.

Nisin application: Adding 0.015–0.02 g/kg Nisin to fresh milk, combined with pasteurization (65°C for 30 minutes), completely kills Bacillus cereus and extends the shelf life of fresh milk from 7 days to 14 days. Adding Nisin to hard cheese production inhibits miscellaneous bacterial contamination during cheese ripening, reducing surface mold growth without affecting cheese flavor or texture.

(III) Fruit and Vegetable Products: Reducing Mold Growth and Replacing Chemical Mold Inhibitors

Green fruit and vegetable products (e.g., fresh-cut fruits/vegetables, fruit/vegetable juices, pickled vegetables) have high water content and are prone to contamination by molds (e.g., Penicillium, Aspergillus) and bacteria (e.g., E. coli). Traditional processes often use chemical mold inhibitors (e.g., calcium propionate).

Nisin application: For fresh-cut lettuce, soaking in a Nisin solution (0.02 g/L for 5 minutes) forms an antibacterial film on the lettuce surface, inhibiting the growth of E. coli and Penicillium and extending the shelf life from 3 days to 7 days. Adding 0.01–0.015 g/kg Nisin to fruit/vegetable juices replaces calcium propionate, avoiding chemical mold inhibitor residues while preserving the natural flavor of the juice.

(IV) Canned Foods: Lowering Sterilization Temperature to Retain Nutritional Components

Traditional processes for green canned foods (e.g., mushroom cans, meat cans) require high-temperature and high-pressure sterilization (121°C for 20 minutes), which easily causes nutrient loss (e.g., >50% loss of vitamin C) and flavor deterioration.

Nisin application: Adding 0.03–0.04 g/kg Nisin to canned food processing reduces the sterilization temperature to 105°C and shortens the sterilization time to 10 minutes, lowering vitamin C loss to <20%. It also ensures no spoilage bacterial contamination (e.g., Clostridium botulinum), meeting the green can requirement of "high nutrient retention and low processing damage."

III. Extended Application Advantages: Empowering the Upgrade of the Green Food Industry

Nisin’s application not only addresses the preservation challenges of green food but also empowers the industry in terms of production efficiency and product innovation.

(I) Reducing Processing Energy Consumption: Aligning with the "Green Production" Concept

The synergy between Nisin and low-temperature sterilization significantly reduces energy consumption in food processing. For example, lowering the sterilization temperature of meat cans from 121°C to 105°C reduces energy consumption by approximately 30% per ton of cans produced. This complies with the green food production requirement of "energy conservation and consumption reduction," reduces carbon emissions, and helps the industry achieve "dual carbon" goals.

(II) Expanding Green Food Categories: Meeting Consumer Demand

Some traditional foods cannot be classified as green food due to "difficulty in preservation" (e.g., low-temperature cooked poultry products). Nisin’s application solves this preservation pain point, enabling such products to be upgraded to green food. For example, green low-temperature roasted chicken products, with Nisin addition and vacuum packaging, can achieve "no chemical preservatives and a 21-day shelf life," filling the gap in green cooked meat product categories.

(III) Enhancing Product Market Competitiveness

Consumer demand for "natural, additive-free" green food grows annually. Foods using Nisin as a natural preservative can be labeled "no chemical preservatives" or "contains natural antibacterial ingredients," enhancing market appeal. They also meet the "clean label" food requirements of international markets (e.g., the EU, the US), facilitating the export of green food.

The application advantages of Nisin in green food production essentially stem from the strong alignment of its "naturalness, safety, efficiency, and environmental friendliness" with green food standards. It not only replaces chemical preservatives to address food preservation and safety issues but also reduces processing energy consumption, lowers environmental burden, and drives product innovation and market expansion. As the green food industry develops, Nisin’s application scenarios will further expand—especially in niche areas such as low-temperature foods and ready-to-eat foods—making it a core component of green food preservation systems.