After the reform and opening up, China's beverage industry has developed very rapidly. The variety of beverages has gradually evolved from simple carbonated beverages to mineral water, juice, fruit and vegetable juice beverages and functional beverages. The filling method has also evolved from cold filling to the present. Hot filling, medium temperature filling, aseptic cold filling, etc.; packaging forms also range from single glass bottles to current cans, PET bottles, etc. For the different products and different packaging forms, the sterilization of the bottle caps is also very important. This article discusses the various methods of sterilizing beverage caps.

First, ultraviolet sterilization

When microorganisms are exposed to ultraviolet light, their proteins and nucleic acids absorb ultraviolet spectral energy, which causes protein denaturation and causes microbial death.

In the beverage filling production equipment, the capping machine transports the cap for the capping machine or the capping machine. The ultraviolet germicidal lamp tube is installed on the upper part of the storage bin of the cover machine or the upper part of the conveyor belt, and the bottle cap is subjected to ultraviolet irradiation during the process of being transported, and the place where the ultraviolet light is irradiated can achieve a better sterilization effect. Due to the poor light transmission of the cap, ultraviolet rays cannot penetrate the cap and illuminate the other side of the cap. Therefore, the cap can only be partially sterilized, and the sterilized surface is random. In order to sterilize the surface of the cap surface in a targeted manner, an ultraviolet germicidal lamp is installed on the glide glides of the capping machine or the capping machine, and the caps here have been arranged in the same direction, and the side of the ultraviolet ray is the cap and the cap. The contact side of the beverage effectively improves the sterilization effect.

The ultraviolet sterilization equipment is simple, no supporting equipment is required, the cost is low, the operation and management are convenient, and the use is relatively wide. Due to the structural characteristics of the slide and the killing characteristics of the microorganisms by ultraviolet rays, the ultraviolet sterilization method is generally suitable for use in the bottle caps of the following types of beverage filling:

1. Carbonated beverage carbonated beverages contain CO2, which is acidic and inhibits the growth of microorganisms. Therefore, the capping of carbonated beverages can meet the demand by ultraviolet sterilization. When the method is produced, the new bottle cap of the batch packaging is poured into the storage bin of the capping machine, and the cap is subjected to ultraviolet irradiation sterilization in the storage bin of the capping machine or on the conveyor belt; it can also be under the capping machine An ultraviolet germicidal lamp is arranged on the cover slide to allow the inner surface of the cap to be irradiated with ultraviolet rays, and is directly sent to the capping machine after sterilization.

2. Mineral water beverage countries have established strict regulations on the production of mineral water, in which the total number of colonies of mineral water, mold count and E. coli are strictly limited to zero. Regardless of whether or not the mineral water has been sterilized, the total bacteria count, mold count and E. coli count must meet national standards. Since mineral water contains only inorganic salts, does not contain microbial nutrient sources, and lacks nutrients for microbial production and development, its caps can also be sterilized by ultraviolet rays.

3. There are various microorganisms (bacteria, mold, yeast, etc.) in high-temperature filled tea drinks, juice drinks, tea drinks and fruit drinks. The sterilization of beverages is to kill these microorganisms. At present, high temperature short-time sterilization method, also known as instantaneous sterilization method, is generally used. High-temperature filling is to fill the temperature after the instantaneous sterilization of the beverage in a temperature range between 85 °C and 92 °C. The beverage bottle is made of heat-resistant hot-filled bottle, and the bottle cap is made of heat-resistant bottle resistant to 85 °C. Cover, filling method is full bottle filling, filling the gland (or screwing) and then adding the bottle refilling device: the bottle body is poured 90°～180°, and the inside of the bottle cap is sterilized by the high temperature of the beverage itself. Therefore, the pre-treatment of the cap can also be sterilized by ultraviolet rays.

Second, hot water spray sterilization

Heat sterilization is one of the most traditional methods of food preservation. When the microbial cells are heated to a certain temperature, the physiologically active substances (such as enzyme proteins, nuclear proteins, deoxyribonucleic acids, etc.) in the cells are denatured and passivated, thereby losing activity and dying. The heating temperature and time for killing microorganisms are significantly different depending on the type of microorganism, the physiological state of cells, and the concentration of cells. For killing a specific strain, increasing the sterilization temperature can shorten the heating time, and lowering the temperature requires prolonging the heating time. If the temperature is too low, the sterilization effect is not obtained for some heat-resistant bacteria.

Hot water jet sterilization is the use of a nozzle to spray hot water in multiple directions on the cap, and also removes dust on the inner and outer surfaces of the cap while sterilizing. In the production method, the caps after the capping are carried in the capping channel in a consistent direction, and a plurality of sets of nozzles are arranged on the upper and lower sides of the channel, and the nozzles perform multi-directional hot water jetting on the advancing caps, and the temperature of the hot water It is the sterilization temperature, and the time to receive the spray is the sterilization time.

Due to its high temperature resistance, the hot metal temperature of the metal cover can exceed 85 °C, and the spray time can be reduced as the hot water temperature increases. For the plastic bottle cap, the hot water temperature is generally controlled at 85 °C. After the hot water is sterilized, it is necessary to spray sterile air on the cap to promote the drying of the cap.

Hot water spray sterilization requires hot water and sterile air. It needs corresponding supporting equipment. It will consume heat energy and a small amount of water when it is produced. It is commonly used in general equipment. Hot water spray sterilization can be used for bottle cap treatment of tea beverages and juice drinks filled at high temperature, and can also be used for bottle cap sterilization of mineral water.

Third, ozone sterilization

Ozone has a very strong oxidizing property, which can directly destroy the viral ribonucleic acid or deoxynucleic acid and kill it. Ozone can also damage the cell membrane of bacteria and mold microorganisms, inhibit its growth, and further penetrate and destroy the tissue in the membrane until the bacteria and mold microorganisms die. Ozone is dissolved in water, and the sterilization effect is very good in a high humidity environment. It is also possible to sterilize the bottle cap with ozone water. Ozone water sterilization will be discussed later. The higher the concentration of ozone, the better the sterilization effect. When the ozone concentration is 4.0 mg/m3, the sterilization time generally takes 45 minutes to 1 hour.

Since ozone sterilization takes a long time, for an automated beverage production line with a certain production capacity, if the sterilization effect is to be satisfied and the sterilization process of the bottle cap is continuously completed in the sterilization equipment, the sterilization equipment needs to be made very large. In the actual production process, the ozone disinfection of the cap is to place a certain amount of caps in a large sealed space in an automated beverage production line with a certain production capacity, and then fill a certain concentration of ozone in the space where the cap is located and keep a section. time. The number of caps placed is determined by the number of caps required to maintain the production. The longer the bottle cap after sterilization, the greater the risk of contamination, so the general storage time is less than one week. The bottle cap after sterilization needs to be isolated from the outside world, and is sent to the capping machine when the capping machine needs the cap.

At present, independent equipment that directly uses ozone sterilization is more common in small cabinet type cap sterilization cabinets. The cap sterilization cabinet has small sterilization space, small production capacity, interval production, and non-automation. When using this ozone sterilization cabinet, it is necessary to manually carry the sterilized bottle cap out of the sterilization cabinet into the conveyor cover machine, which is likely to cause secondary pollution of the bottle cap. Therefore, ozone sterilization is only suitable for non-automated production lines, or small production lines that have certain sterilization requirements for bottle caps.

Fourth, sterilization water sterilization

There are unstable elements in the sterilizing water, which will decompose on their own. Sterilization water sterilization is the use of this decomposition process (oxidation process) to oxidize microorganisms on the surface of the object to achieve sterilization purposes.

Common substances with strong oxidizing properties are: peracetic acid, ozone water and chlorine water. The instantaneous bactericidal properties of ozone are better than chlorine. At present, the sterilizing water for sterilizing beverage caps is basically peracetic acid and ozone water, and most of them are peracetic acid. The greater the concentration of sterilizing water, the shorter the sterilization time required. For peracetic acid at 65 ° C and 2000 PPM, the bottle cap can be brought to commercial sterility by sterilization from 30 seconds to 60 seconds. Due to the short sterilization time and good sterilization effect of sterilizing water, it is widely used in the sterilization of bottles and lids for fruit and vegetable juice beverages. The method of sterilizing the beverage bottle cap by using sterilizing water mainly includes a spray type and a immersion type.

1. The spray type adopts multiple sets of nozzles, and sprays the sterilizing water in multiple directions of the bottle cap to sterilize the surface of the cap. The time for the cap to be sprayed should ensure that the microorganisms can be completely killed. The specific method is as follows: the caps after the caps are uniformly inserted into the cap rails, and a plurality of sets of nozzles are arranged on the upper and lower sides of the rails, and each set of nozzles can spray the sterilization water from the different angles, and the sprayed sterilization water is Sterilization of the cap also pushes the cap along the track.
When peracetic acid is used as the sterilizing water, the cap after the sterilizing water is sprayed needs to be rinsed with sterile water to remove the residual peracetic acid on the cap, so that the residual amount is lower than the relevant standard; after rinsing with sterile water Dry the cap with sterile air.

When ozone water is used as sterilizing water, since the product after decomposition of ozone water is water and oxygen, there is no harmful residual substance. Theoretically, it is not necessary to treat the bottle cap again, but in the actual production process, due to the outlet of the cap sterilizer It is close to the capping machine and can not completely decompose the residual ozone. Therefore, after the bottle cap is sterilized by ozone water, it needs to be rinsed with sterile water and dried by sterile air.

Due to the linearity of the spray water, the sterile water spray sterilization can be used for the sterilization of the mineral water bottle cap, and can also be used for the sterilization of the bottle cap during the hot filling of the tea beverage and the juice beverage. The hot filling is filled with full bottle, and after filling the cap, the bottle is heated and the bottle is heated for internal sterilization.

2. The immersion type completely immerses the beverage bottle cap in the sterilizing water, so that all the inner and outer surfaces of the bottle cap are sterilized by the sterilizing water, and the immersion time should meet the time requirement for the complete sterilizing of the bottle cap. One method is: the bottle cap with the same direction is fixed on the cap rack, the cap rack is connected to the chain, and the movement of the chain drives the cap rack into the sterilizing tank containing the sterilizing water and completely immerses the cap in the sterilizing water. The time of soaking should meet the time requirements for complete sterilization. As with the blasting method, the caps immersed in sterilizing water also require the rinsing of sterile water and the blasting of sterile air to make the cap dry and sterile.

When using sterile water sterilization method, the sterilizing water, sterile water and sterile air required for it need to be produced and processed, and there are many peripheral supporting equipments, high cost, high cost, high management requirements, and therefore sterilization. The process is generally applied to the aseptic cold filling of juice drinks.

Five, electrolyte sterilization

Electrolysis is the use of an inert electrode to energize the liquid, the oxidation of the anode, and the reduction of the cathode. At present, relevant foreign personnel have studied the use of completely demineralized drinking water and sodium chloride dilute solution to produce electrochemical reaction, in the anode region to obtain better sterilization effect than the traditional sterilization water sterilization solution. If the electrolysis principle is directly used for bottle cap sterilization, the transportation and storage costs can be greatly reduced, saving time and effort, and being safe and effective.

to sum up

Analyze the above sterilization methods of various caps, and select different cap sterilization processes according to the composition characteristics and quality requirements of different beverages, as shown in the table: