PHMG Food Preservation Technology: Safe Bacteriostasis and Long-term Antiseptic Properties

Polyhexamethylene guanidine (PHMG), as a new type of polymer antibacterial agent, has demonstrated breakthrough application value in the field of food preservation in recent years. Its broad-spectrum bactericidal properties, low toxicity, environmental friendliness, and long-term antibacterial capabilities make it an important alternative to traditional preservatives. The following are its innovative applications and technical advantages in food preservation:

I. Prevention and Control of Post-harvest Diseases of Fruits and Vegetables

PHMG can effectively inhibit common post-harvest diseases of fruits and vegetables, such as citrus sour rot and strawberry gray mold, by disrupting the cell membrane structure of pathogenic bacteria. Studies have shown that soaking treatment with an aqueous solution of PHMG at a concentration of 0.02%-0.1% can significantly reduce the number of foodborne pathogenic bacteria, such as Escherichia coli and Salmonella, on the surface of fruits and vegetables. This can extend the shelf life of fruits like grapes and apples by 15-20 days. For vegetables with sensitive epidermis, such as cucumbers, PHMG treatment can reduce the problem of residual available chlorine and will not cause epidermal browning.

II. Preservation and Quality Improvement of Aquatic Products

In the processing of aquatic products, a two-stage application system of PHMG has been established:

Raw Material Pretreatment: Soaking fish and shrimp raw materials in a 0.02% concentration solution can remove more than 99% of aquatic pathogenic bacteria, such as Vibrio parahaemolyticus and Vibrio alginolyticus, within 3 minutes.

Cold Chain Transportation Assurance: Adding PHMG to ice packs or cold chain packaging films (at a concentration of 0.05%-0.1%) can not only inhibit the proliferation of microorganisms but also reduce the damage of ice crystals to the muscle tissue of aquatic products.

III. Disinfection of Food Processing Equipment

Compared with chlorine-containing disinfectants, PHMG has significant advantages in the disinfection of food machinery:

It does not corrode stainless steel equipment, avoiding the risk of metal ion migration caused by traditional disinfectants.

Treatment of beverage filling pipelines with a 0.1% concentration can maintain a bactericidal effect for 72 hours, reducing the production cost caused by frequent disinfection.

Spraying PHMG treatment agents on the surface of baking equipment can effectively inhibit the growth of yeast and extend the equipment cleaning cycle.

IV. Modification of Food Packaging Material

By compounding PHMG (0.3%-0.5%) into PLA biodegradable packaging films, environmentally friendly materials with both antibacterial and preservative functions can be developed:

For fresh meat packaging, the antibacterial rate is 40% higher than that of traditional PE films.

When acting in synergy with chitosan, it can delay the enzymatic browning reaction of fresh-cut fruits and vegetables.

Safety and Technical Specifications

The safety of PHMG in food applications has been verified through multiple tests:

- Residue detection shows that the residual amount of PHMG on the surface of treated fruits and vegetables is less than 0.1 ppm, which is far lower than the safety standard for food contact materials in the European Union.

- The acute oral toxicity test shows that the LD50 is greater than 5000 mg/kg, indicating that it is practically non-toxic.

- China's "Technical Specification for Disinfection" (2022 edition) has included it in the recommended list for disinfection of food processing environments.

Currently, in the application of this technology, it should be noted that the treatment concentration needs to be adjusted according to the type of food (0.02%-0.1% for fruits and vegetables, 0.01%-0.05% for aquatic products), and it should be avoided to be used in combination with anionic detergents. With the acceleration of research and development of functional food packaging, the application potential of PHMG in scenarios such as the preservation of prefabricated dishes and the sanitation management of central kitchens will continue to be released.