Pulsed light (PL) technology is an emerging processing method that utilizes short duration pulses of intense, broad-spectrum light for the sterilization of surface. Applying one or more flashes of pulsed light to microorganisms causes their immediate, total and irreversible destruction.
This destruction is based on two mechanisms:
Photochemical sterilization refers to the short-wave UV rays that can penetrate the microbial cell wall to act on the internal genetic material of the microorganism, causing the ectopic or fracture of the double helix structure to achieve the killing effect.
This mechanism is the bactericidal mechanism of a conventional DC-UV lamp (main waveband 254 nm). Since the light emitted by the pulsed light is a broad spectrum and contains an ultraviolet band of 200-400 nm, it also has a photochemical sterilization effect. However, since short-wave ultraviolet rays need to penetrate the external structure of the microorganisms to be absorbed by the internal substances, the microbial killing effect of many cell walls by this sterilization mechanism is not satisfactory.
Photothermal sterilization is the unique and main mechanism of pulsed light technology. The mechanism is that the peak power of the high-intense light directly flashing the surface of the microorganism, destroying the cell wall structure of the microorganism, causing the loss of the microbial function and cell fluid until death. This mechanism of action makes pulsed light achieve high efficiency of sterilization for all microorganisms, up to log 6.
Compared to other sterilization methods, such as heat or chemical disinfectant treatment, PL treatment has several advantages:
High efficiency, Broad spectrum, Environmental protection, No obvious heating and Flexibility.
PL can achieve remarkable decontamination results on microorganisms such as mold, Gram-positive pathogens, Gram-negative pathogens, aerobic cell sprouts and fungal conidia, Staphylococcus aureus, Bacillus subtilis, and yeast.
Pulsed light as a new surface cold sterilization technology, its safety for food sterilization has also been approved by the US FDA. Pulsed light has outstanding bactericidal effects when dealing with simple surface objects and transparent media (water, air, etc.), and also has a certain bactericidal effect on the surface of opaque and irregular foods, which can effectively extend the shelf life of products and improve safety.