The purpose of applying ozone in the food industry is three-fold: first, to kill microorganisms – sterilization and disinfection; second, to oxidatively decompose organic or inorganic pollutant odors – deodorization and purification; third, to decompose fruit and vegetable metabolites and inhibit the post-ripening process – preservation. The application foundations of the three aspects all rely on the strong oxidizing properties and unstable and easy decomposition characteristics of O3.

Disinfection

Ozone is a gas disinfectant. Its sterilization process is a strong oxidation reaction that causes multiple components in microbial cells to react, resulting in irreversible changes and death. It is generally believed that ozone inactivates viruses by directly destroying their ribonucleic acid (RNA) or deoxyribonucleic acid (DNA) substances. To kill bacteria and mold microorganisms, ozone first acts on the cell membrane, causing damage to the membrane components, causing metabolic disorders and inhibiting their growth. Ozone continues to penetrate and destroy the tissue within the membrane until it is killed. Increased humidity increases the killing rate because cell membranes swell and become thinner under high humidity, and their tissues are easily damaged by ozone.

Deodorization and purification

Ozone has excellent odor removal performance. Relying on its oxidizing properties, it can quickly decompose organic or inorganic substances that produce odors and other odors. Ozone oxidizes and decomposes it, and the product has no smell.

Keep fresh

The application of ozone in the storage of vegetables and fruits not only kills or inhibits mold growth and prevents rot, but also prevents aging and preserves freshness. The mechanism is that ozone can oxidize and decompose the ripening agent-ethylene gas C2H4 breathed out by the physiological metabolism of fruits and vegetables. The reaction process is as follows: H2C-CH2+O3→C2H4O+O2→CO2+H2O

The ethylene intermediate product C2H4O also has an inhibitory effect on microorganisms such as mold.

Application places of ozone air disinfection machine

1. Cold storage disinfection

The main source of biological pollution in cold storage is mold. Because it survives under low temperature conditions and has strong tolerance to disinfectants, all ungerminated spores, including extremely resistant spores, will be killed under the action of 12ppm ozone for 3-4 hours. .

In my country, high-temperature cold storage for storing eggs, fruits and vegetables attaches great importance to the disinfection of empty storage. Cold storage disinfection requires ozone concentration of 6-10ppm, and the warehouse should be closed for more than 24 hours after shutdown. The bacterial killing rate is about 90%, and the mold killing rate is about 80%. At this time, the sterilization process is longer. On-site measurement shows that the number of microorganisms is still declining after 48 hours of shutdown, and the ozone has already been decomposed. Therefore, it is required that the ozone disinfection time be arranged one week before the purchase.

2. Sterilization and purification in food processing workshops

Quick-frozen food, cold food, meat, egg and dairy products processing workshops and packaging rooms all have relatively high hygiene requirements. Especially for fresh food, since there is no final heating and disinfection process, microbial contamination in the production workshop is an extremely important factor affecting product quality. At present, most of our country uses ultraviolet lamp for disinfection. Due to the aforementioned natural shortcomings of ultraviolet sterilization, it is difficult to control food microbial indicators, especially in summer. Ozone is very effective in disinfecting food processing workshops, and its concentration is much lower than the requirements for cold storage disinfection. Generally, 0.5-1.0 ppm can achieve an air sterilization rate of more than 80%, and can remove odors in the workshop. Egg processing factories produce mayonnaise, and cold drink factories produce ice cream and ice cream, all of which have mixing and puffing processes. The products are in strong contact with the air. After using ozone, the microorganisms in the workshop were reduced by 90%, and the product quality reached the qualified standard. Once the use of ozone is stopped, the products will The bacterial content increases rapidly day by day.

3. Storage of vegetables and fruits to prevent mildew and preserve freshness

The storage and preservation of vegetables and fruits is a complex and difficult task. Ozone can play a role in sterilization, mildew prevention and slowing down metabolism. It can be used together with packaging, refrigeration, air conditioning and other means to improve the preservation effect.

Ozone sterilization and mildew prevention are applied in three stages: air disinfection, warehouse sterilization and daily mildew prevention. The purpose is to reduce rot caused by mold, yeast and other microorganisms. Ozone quickly decomposes ethylene to slow down the metabolic process and delay after-ripening and aging.

4. Sterilization and quality preservation of mineral water

Drinking water sterilization and purification is an area where ozone is widely used. At present, the main market of the world’s ozone industry is still drinking water treatment. In developed countries such as Europe, the United States, and Japan, ozone-treated drinking water has taken a dominant position. The reason is that ozone treatment can achieve a high level of no microbial contamination and no residual chemical contamination.

Mineral water is already a widely consumed bottled beverage, and its shelf life depends on the complete killing of microorganisms. The commonly used method of ultrafiltration and ultraviolet disinfection is difficult to meet quality standards. Ozone sterilization has become the preferred method. It can completely kill living microorganisms and achieve double-zero indicators. It can also remove soluble iron and manganese salts in the water and preserve beneficial carbon oxygen. compound.

It is very beneficial for manufacturers without air filtration and purification equipment to install ozone equipment in the mineral water filling room to sterilize and purify the air and prevent contamination by falling bacteria. Mineral water plants that use ozonation technology often use ozone to disinfect water storage tanks (tanks), pipes, and filters. It is also very effective and is recommended as an experience in foreign materials.

5. Disinfection of work clothes

Some processes in food processing, cold drinks, biochemical pharmaceuticals and other departments have very high requirements for the disinfection of work clothes. High-pressure sterilization is often used to sterilize work clothes, which is difficult to achieve in the food industry. Food manufacturers use ozone to disinfect work clothes, which is an efficient, economical and simple method.

For example, in the food industry, work clothes are disinfected after work every day, dozens of work clothes are hung up in a 20m2 closed room, and some water is sprinkled on the ground. For example, if you use a 3g/h generator and turn it on for 3-4 hours, you can achieve a disinfection effect of 8-10ppm ozone concentration and a killing rate of more than 85%. Hanging work clothes in the ozone sterilization workshop has a disinfecting effect, and the effect varies depending on the concentration.