The preservative effect of Nisin in aviation food

As a natural peptide bacteriostatic agent, nisin boasts the advantages of high efficiency, safety, and strong adaptability in the preservation of airline catering. Its antiseptic effect is optimized for the special storage, transportation, and consumption scenarios of airline catering (low-temperature/room-temperature warehousing, long-distance transportation, and short-term storage without cold chain). The specific effects and application essentials are as follows:

I. Core Antiseptic and Fresh-Keeping Effects: Targeted Inhibition of Pathogens and Shelf-Life Extension

1. Antibacterial Spectrum Precisely Matches Common Spoilage Bacteria in Airline Catering

Nisin exerts potent inhibitory effects on Gram-positive bacteria that are prone to causing spoilage and safety risks in airline catering. These include pathogenic bacteria such as Clostridium botulinum, Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus, as well as spoilage bacteria like lactobacilli and streptococci that lead to food acidification.

For thermally processed meat products (e.g., chicken sausages, beef jerky), ready-to-eat rice, cheese products, and pastries in airline catering, adding 0.05–0.2 g/kg of Nisin can extend the room-temperature shelf life by 2–3 times. For example, the shelf life of ready-to-eat chicken rice without Nisin is only 24 hours at 25℃, while adding 0.1 g/kg of Nisin can extend it to 72 hours, fully meeting the 72-hour cycle requirement of "production – catering – consumption" in air transportation.

2. Synergizing with Thermal Processing to Improve Sterilization Efficiency and Reduce Nutrient Loss

Airline catering usually requires high-temperature sterilization to ensure safety, but excessive heating can cause protein denaturation and vitamin loss, affecting taste and nutrition. Nisin can work synergistically with thermal processing to lower the sterilization temperature (e.g., from 121℃ to 105℃) or shorten the sterilization time while maintaining equivalent sterilization efficacy. This combination of "mild thermal processing + Nisin" can reduce the taste deterioration of ready-to-eat airline meals, and is particularly suitable for heat-sensitive airline products such as desserts and vegetable salad dressings.

3. Adapting to the Storage and Transportation Environment of Airline Catering to Inhibit Spore Germination

Airline catering may experience temperature fluctuations during transportation (e.g., the cargo hold temperature rising to 30℃ for a short time), which can easily induce the germination and proliferation of heat-resistant spore-forming bacteria. Nisin can directly inhibit the growth of vegetative cells after spore germination by destroying the integrity of bacterial cell membranes and inhibiting cell wall synthesis, thus avoiding spoilage caused by temperature fluctuations. Moreover, its antibacterial activity remains stable within the pH range of 3.0–6.5, which is compatible with the acidity and alkalinity of most airline catering products.

II. Unique Advantages for Airline Catering Application: Compliance with Safety Standards and Adaptation to Special Needs

1. High Safety with No Residue Risk

Nisin is a metabolic product of natural lactic acid bacteria. After being ingested by the human body, it can be decomposed into amino acids by proteases in the digestive tract without cumulative toxicity. It complies with the food additive safety standards of the FAO/WHO and meets the safety requirements for catering food set by the International Air Transport Association (IATA). Its dosage is far below the ADI value (acceptable daily intake: 33,000 IU/kg body weight), so it will not pose a health risk to passengers. Additionally, it has no off-flavor associated with chemical preservatives and does not alter the flavor of airline catering.

2. Strong Compatibility Without Affecting Food Sensory Quality

Airline catering has strict requirements for taste and color. Nisin is colorless and tasteless; its addition will not change the appearance and flavor of food, and it has good compatibility with components such as starch, protein, and oil in airline catering without causing precipitation or delamination. Compared with chemical preservatives such as potassium sorbate and sodium benzoate, Nisin is more suitable for the preservation of high-end airline catering (e.g., business-class steaks and desserts).

3. Adapting to Short-Term Storage Scenarios Without Cold Chain

Some low-cost airlines do not provide full cold-chain catering services, and food needs to be stored at room temperature in the cabin for 2–4 hours. Nisin has high stability at room temperature and can continuously exert antibacterial effects without cold chain, reducing the safety risk of food during cabin storage. This is an irreplaceable advantage over preservation technologies that rely on cold chain.

III. Application Precautions: Optimizing Formulation and Process to Enhance Efficacy

1. Compound Application to Expand Antibacterial Spectrum

Nisin has weak inhibitory effects on Gram-negative bacteria, while cold dishes and fruit salads in airline catering may be contaminated by Gram-negative bacteria such as Escherichia coli. Nisin can be compounded with EDTA (ethylenediaminetetraacetic acid); EDTA can destroy the outer membrane structure of Gram-negative bacteria, allowing Nisin to penetrate the cell membrane and exert its antibacterial effect, thus achieving broad-spectrum antibacterial activity.

2. Controlling Addition Timing and Process

Prolonged heating at high temperatures (>121℃) can reduce the activity of Nisin. Therefore, it should be added in the later stage of thermal processing or during the cooling phase after sterilization. For vacuum-packaged airline catering, tight sealing should be ensured after Nisin addition to avoid secondary contamination.

3. Complying with Regional Regulatory Requirements

The maximum allowable dosage of Nisin varies slightly among different countries. For example, the EU stipulates that the maximum addition amount of Nisin in meat products is 0.5 g/kg, while China's national standard GB 2760-2014 National Food Safety Standard for the Use of Food Additives specifies that the addition amount of Nisin in ready-to-eat food shall not exceed 0.2 g/kg. Airline catering production should adjust the dosage according to the regulations of the target route destinations.