1. Introduction of ozone technology

Ozone technology, a dual legacy of antiquity and innovation, has embarked on its extraordinary journey since its invention by a German chemist in 1840. After its discovery in 1840, ozone was rapidly adopted for water treatment disinfection and has recently gained widespread application in the food industry due to concerns over chemical disinfectant residues. By 1856, it had become a standard solution for water treatment disinfection, demonstrating exceptional bactericidal efficacy. As food contamination caused by chemical disinfectant residues has become increasingly prominent in recent years, ozone technology has emerged as a novel disinfectant in the food industry, achieving broad promotion and application.
Between 1995 and 1996, countries such as Japan, France, and Australia successively enacted regulations explicitly permitting the widespread use of ozone technology in the food industry. Subsequently, the U.S. Food and Drug Administration (FDA) also lifted its previous restrictions on the use of ozone in food processing in 1997, confirming that ozone applications in food processing met the requirements of the Generally Recognized As Safe (GRAS) standard.

In 1785, the Germans accidentally discovered that the motor emitted a distinctive odor during discharge. By 1840, French scientists further identified this odor as O₃ and named it ozone. Since then, numerous European scientists have devoted themselves to in-depth exploration of ozone’s properties and functions.

Advantages of Ozone Application

Compared with chemical agents, ozone (O₃) demonstrates significant advantages as a highly effective bactericide. Recognized globally as the most ideal disinfectant, ozone is an efficient and environmentally friendly sterilizing agent characterized by its residue-free properties, high cleanliness, and cost-effectiveness. Unlike chemical-based sterilization that involves adding substances, ozone is generated through the excitation of oxygen molecules in the air. Its sterilization process is instantaneous, with the produced ozone rapidly reverting to oxygen post-use, leaving no residual traces and posing no health risks to personnel. Consequently, ozone is universally acknowledged as an ideal disinfectant that achieves both high efficacy and environmental safety without agricultural residues.
Compared with conventional sterilization methods, ozone disinfection and sterilization exhibits the following significant characteristics:
(1) High efficiency: Ozone disinfection and sterilization utilize air as the working medium, requiring no additional auxiliary materials or additives. It achieves thorough and comprehensive sterilization effects, while effectively eliminating odors such as mold, fishy, and foul smells.
(2) High cleanliness: As ozone rapidly decomposes into oxygen, no residual substances are left. This characteristic not only resolves the potential secondary contamination issue caused by disinfectants but also eliminates the need for post-disinfection cleaning procedures.
(3) Convenience: The ozone sterilizer can be easily installed in cleanrooms, air purification systems, or sterilization chambers, such as ozone sterilization cabinets and pass-through windows. By presetting the sterilization concentration and duration, the operation of the sterilizer can be conveniently controlled.
(4) Cost-effectiveness: In the comparison of application and operation between the pharmaceutical industry and healthcare institutions, ozone disinfection methods demonstrate significant economic and social benefits, outperforming other disinfection methods.

2. Application of ozone technology in food industry sterilization and disinfection

In food production facilities, ozone technology is extensively utilized for sterilization and surface disinfection. As a highly effective bactericide, it achieves 300-600 times faster sterilization than chlorine, rapidly eliminating pathogenic microorganisms such as Escherichia coli, Salmonella, and Staphylococcus aureus. Ozone demonstrates exceptional sterilization capabilities in the food industry, effectively eliminating various pathogens without residue, surpassing traditional methods like ultraviolet (UV) radiation. Compared to conventional food industry disinfectants, ozone exhibits superior sterilization efficacy with no residual contamination, outperforming UV irradiation. It ensures comprehensive sterilization coverage while reducing treatment time. Additionally, low-concentration ozone maintains air cleanliness in production areas, compensating for the limitations of UV irradiation. With continuous advancements in ozone application technologies, its role in the food industry is becoming increasingly prominent.

Concentration and Usage

The bactericidal efficacy of ozone in air is closely related to its concentration. The bactericidal effect of ozone varies with its concentration and requires adjustment according to different applications. Concentration control is key to ensuring both effectiveness and safety.

Different concentrations of ozone are suitable for various application scenarios. Below is a table outlining the commonly used concentrations and application methods of ozone for air sterilization:
Please note that the concentrations listed in the above table are for reference only and should be adjusted according to specific conditions during actual use. Additionally, when using ozone for sterilization, it is essential to adhere to relevant safety operating procedures to ensure personnel safety.

Fruit and Vegetable Storage and Preservation

Ozone plays a significant role in the storage and preservation of fruits and vegetables. It inhibits the expression of certain genes and reduces the activity of aminocyclopropanecarboxylic acid synthase and aminocyclopropanecarboxylic acid oxidase, thereby decreasing ethylene biosynthesis and delaying fruit ripening. Ozone suppresses the expression of key genes during the ripening process, reduces ethylene biosynthesis, and maintains freshness and safety. Additionally, ozone treatment significantly alleviates cell wall swelling in fruits and vegetables, inhibits the dissolution of pectin and neutral sugars, and reduces the activity of cell wall-degrading enzymes, thereby minimizing flesh softening and cell wall breakdown.
Disinfection of production equipment.

In industries such as food processing, cold beverage production, and biochemical pharmaceuticals, the disinfection of workwear is crucial. Although the traditional ultraviolet (UV) lamp irradiation method is widely used, its effectiveness is limited to the areas directly exposed to light waves, resulting in a restricted irradiation area and suboptimal disinfection outcomes. Ozone, compared to conventional UV methods, is more efficient and economical, making it suitable for workwear disinfection and providing superior disinfection results. In contrast, ozone-based workwear disinfection demonstrates higher efficiency, cost-effectiveness, and simplicity, emerging as a superior alternative.

Production Water and Mineral Water Treatment

The food production industry requires massive amounts of clean water, which often accounts for a significant portion of production costs. However, ozone technology can effectively address this challenge by treating substandard water quality. Ozone technology not only effectively sterilizes but also removes impurities from water, ensuring both water quality and the shelf life of mineral water. Similarly, the shelf life of mineral water has become a major concern. Since microbial growth can severely impact the quality of mineral water, thorough sterilization is crucial. Although filtration combined with ultraviolet disinfection was once widely used, its sterilization effectiveness often fell short of expectations. In contrast, ozone sterilization technology can more effectively eliminate microorganisms while removing impurities such as iron, manganese, and soluble salts from water, ensuring the retention of beneficial carbon oxides and thereby extending the shelf life of mineral water.
Degradation of pesticide residues

Through extensive research and experimentation, we have discovered that traditional pesticide removal methods such as water soaking and rinsing can only eliminate approximately 10% of residual pesticides, with soaking being effective only for water-soluble pesticides. Notably, among the over 200 types of pesticides available in China’s market, most are insoluble in water, making conventional dishwashing detergent ineffective. Moreover, many dishwashing detergents contain inexpensive sodium alkylbenzene sulfonate as their primary ingredient, which often introduces new contamination issues when used for washing vegetables and fruits. Ozone effectively degrades pesticide residues in vegetables by breaking chemical bonds, achieving a removal rate as high as 95%.

Bleaching and Decolorization Effects

In the food industry, ozone has demonstrated unique bleaching and decolorization capabilities. In sugar production, traditional methods rely on sulfur dioxide as a clarifier, but this approach leaves residual sulfur, imposing certain usage limitations. As a natural bleaching agent, ozone can replace conventional chemical clarifiers, offering significant decolorization effects without residual pollution. Studies show that ozone serves as a potential alternative solution. By precisely controlling processing conditions, it not only meets expected decolorization requirements but also avoids toxic chemical residues. Additionally, ozone performs excellently in whey protein bleaching. Traditionally, hydrogen peroxide or benzoyl peroxide are commonly used bleaching agents, but they may alter the original flavor of whey powder. In contrast, ozone achieves comparable bleaching effects to hydrogen peroxide under specific conditions while preserving the original flavor of whey powder.

3. Safety considerations about ozone usage

In the food industry, the primary concern when applying ozone is its safety. While ozone toxicity to humans is a critical consideration, it poses no health risks when maintained within appropriate concentration ranges. People begin to detect ozone at concentrations exceeding 0.15 mg/L, and adverse effects may occur only when concentrations surpass 10 mg/L. Therefore, keeping ozone concentrations within safe limits ensures its safe use in food production without leaving residual traces on food products.