Mold likes to grow in damp places. Because it can adapt to lower temperatures, it is most serious in the high-temperature warehouse of the refrigeration plant. After it grows in the cold storage, the spores fly everywhere, which has a great impact on the quality of meat and eggs, so mold is the main hazard in the cold storage. Unlike pathogenic bacteria, the mold itself is harmless and does not produce toxins, but it seriously damages the appearance of commodities and promotes the mildew and deterioration of meat and eggs. There are three types of mold removal methods: mechanical mold removal, physical mold removal, and chemical mold removal.
1. Mechanical Mildew Removal
It is to clean and eradicate the moldy part, which is often combined with other methods. There is an air scrubbing method in the mechanical mildew removal method, which is to install a water sprayer at the air inlet, and the air is circulated through the water to wash away the mold spores. This method is the same as the current wet air cooler, which can reduce the effect of mold.
2. Physical Mildew Removal
It uses temperature, humidity, ultraviolet light, high-frequency electricity, and copper wire mesh filters to remove mildew. Its growth temperature is generally -6 to 40 ° C, so it is rarely seen in low-temperature storage, and it can also be killed on tools by using hot alkaline water. Its growth is closely related to temperature, so the control in temperature can only be used appropriately.
Ultraviolet light is a better way to remove mildew. It can not only sterilize, but also remove mildew, and also has some deodorizing effects. But this can only work on the directly irradiated part, generally, 0.33 to 3.00 watts of ultraviolet light per cubic meter is used. Irradiation on an area 2 meters away for 6 hours can kill microorganisms. However, the effect of ultraviolet light is affected by temperature and humidity. The closer it is to the normal temperature for microbial growth, the higher the humidity, the stronger the ability to sterilize and remove mildew.
The copper wire mesh filter is a mesh made of copper wire installed on the reverse air outlet, which can kill part of the mold.
3. Chemical Mildew Removal
There are many methods of this method, such as lactic acid, carbon dioxide, ozone, formaldehyde, bleaching powder, sodium fluoride, sodium hydroxybiphenol, etc.
3.1. Lactic acid method is a reliable disinfection method, which can remove mold, sterilize and deodorize. The use method is to clean the warehouse first, use 1 ml of crude lactic acid per cubic meter, add 1 to 2 parts of water, put the mixture in an enamel basin, and heat it on an electric stove to evaporate. It is generally required to control the liquid medicine to evaporate in about half an hour to 3 hours. Then turn off the electric furnace and seal the warehouse door for about 6 to 24 hours, so that the lactic acid can fully interact with bacteria or mold, in order to achieve the purpose of disinfection. The bacteria in the sterilized warehouse decreased by 70%, and the mold decreased by 70%.
3.2. The carbon dioxide method cannot kill mold at any concentration, it can only delay the growth of mold. However, below 0°C, if the concentration of carbon dioxide in the indoor air reaches 40%, the growth of mold can be completely prevented. However, when its concentration in the air exceeds 20%, it discolors the meat due to the formation of denatured hemoglobin. It is generally believed that when the concentration of indoor carbon dioxide is 10% below 0 °C, the shelf life of cooled meat can be more than doubled.
3.3. Ozone method is a better method, which can not only sterilize but also remove mold and odor. In this way, an ozone generator should be used to crack two atoms of oxygen in the air into two atoms of ozone. The formed ozone is injected into the cold storage, and its concentration is about 1 to 3 mg/cubic meter. However, ozone is a strong oxidant, which can make lean meat fade and fat oxidize, and ozone can stimulate human mucous membranes, so you should pay attention when using it.
3.4. The formaldehyde method is the formalin vapor method. This method can detoxify and sterilize, but it has a strong smell and cannot be eaten if it is absorbed by the meat. At the same time, formalin is very irritating to people, so pay attention to safety when using it. Before using this method, the warehouse should be emptied and cleaned, generally 15 ml per cubic meter. There are two ways to make formalin into steam: one is to put it in an airtight barrel and pass it into the cold storage with a pipe, and burn it with fire below. One is to put it in an open bucket and put it in the cold storage, and the operator will put an appropriate amount of potassium permanganate or quicklime, add some water, and when gas occurs, the personnel will go out and close the door. After sterilizing with formalin steam for several hours, put it in the room with ammonia water to absorb the smell of formalin, and it is completed after ventilation and sterilization.
3.5. The bleaching powder method is to use 4% bleaching powder solution for brushing, and the disinfection effect is good. If it is better to add 7 parts of lime caustic soda to 5 parts of bleaching powder, disinfect for a few hours to ventilate and exhaust.
3.6. The sodium fluoride method is to paint the walls with a mixture of 2% sodium fluoride and 20% kaolin, and it can be mildew-free for 1 to 2 years at 0 °C.
3.7. The sodium hydroxydiphenate method is to use 2% sodium hydroxydiphenate solution to brush and remove mildew. In this method, the smell can not be transmitted to the meat, and it will not corrode the utensils, but it is necessary to take protective measures when painting.
