What are the sterilization methods and applications of various beverage bottle caps?

The development of China’s beverage industry is very rapid, and the varieties of beverages have gradually developed from simple carbonated beverages in the past to mineral water, fruit juice, fruit and vegetable juice drinks and functional drinks. Filling methods have also developed from cold filling to hot filling, medium temperature filling, sterile cold filling, etc. The form of packaging has also changed from a single glass bottle to the current cans, PET bottles and so on. According to different products and different packaging forms, the sterilization treatment of packaging bottle caps is also very important. This paper discusses the sterilization methods of various beverage bottle caps currently used.
Ultraviolet sterilization
After microorganisms are irradiated by ultraviolet light, their proteins and nucleic acids absorb the ultraviolet spectral energy, which will lead to protein denaturation and cause microbial death.
In the beverage filling production equipment, the capping machine delivers the bottle cap for the capping machine or the capping machine. The upper part of the storage bin or the upper part of the conveyor belt is installed with ultraviolet bactericidal lamps. The bottle cap receives ultraviolet radiation during the conveying process, and the place where ultraviolet radiation reaches can achieve better bactericidal effect. Due to the poor light transmission of the bottle cap, ultraviolet rays cannot penetrate the bottle cap to the other side of the cap. Therefore, the bottle cap can only achieve partial sterilization, and the sterilization surface is random. In order to specifically sterilize the surface of the bottle cap, install ultraviolet germicidal lamps on the sliding path of the bottle cap of the capping machine or the capping machine, through which the bottle cap has been arranged in the same direction, the side of the ultraviolet irradiation is the side of the bottle cap in contact with the beverage, effectively improving the germicidal effect.
Ultraviolet sterilization equipment is simple, no supporting equipment, low cost, convenient operation and management, and widely used. Due to the structural characteristics of the slide and the killing characteristics of ultraviolet rays on microorganisms, the ultraviolet sterilization method is generally suitable for use in the bottle caps of the following types of beverage filling:
1. Carbonated beverages Carbonated beverages contain CO2, which is acidic and can inhibit the growth of microorganisms, so the bottle cap of carbonated beverages can meet the needs of ultraviolet sterilization. In the process of production, the new bottle caps packed in batches are poured into the storage bin of the cap conveying machine, and the bottle caps are sterilized by ultraviolet radiation in the storage bin of the cap conveying machine or on the conveyor belt. The UV germicidal lamp can also be set on the lower cover slide of the capping machine, so that the inner surface of the bottle cap can be irradiated by ultraviolet light to sterilize, and then directly transmitted to the capping machine after sterilization.
2. Mineral water beverage The state has formulated relatively strict regulations on the production of mineral water, among which the total number of bacterial colonies, mold counts and Escherichia coli in mineral water are strictly limited to zero. Regardless of whether the mineral water has been filtered and sterilized, its total bacterial count, mold count and E. coli count must meet national standards. Because mineral water only contains inorganic salts, does not contain microbial nutrient sources, lack of nutrients for microbial production and development, so the bottle cap can also use ultraviolet sterilization.
3. High temperature filling tea drinks, juice drinks Tea drinks and juice drinks exist in a variety of microorganisms (bacteria, mold and yeast, etc.), beverage sterilization is to kill these microorganisms. At present, high temperature short-term sterilization method is generally used, also known as instantaneous sterilization method. High temperature filling is to cool the beverage after instantaneous sterilization in a temperature range between 85 ° C and 92 ° C for filling. The beverage bottle should be filled with a crystalline heat-resistant hot-filling bottle, and the bottle cap should be heat-resistant to 85 ° C. The filling method should be full bottle filling, and the bottle pouring device should be added after filling the cap (or screw the cap) : Pour the bottle 90° ~ 180°, use the high temperature of the beverage itself to sterilize the inside of the bottle cap. Therefore, the early treatment of the bottle cap can also use ultraviolet sterilization.
Hot water spray sterilization
Heating sterilization is one of the most traditional methods of food preservation. If microbial cells are heated to a certain temperature, the physiologically active substances in the cells (such as enzyme proteins, nuclear proteins, deoxyribonucleic acid, etc.) will undergo denaturation and passivation, thus losing their activity and dying. The heating temperature and time to kill microorganisms are obviously different according to the types of microorganisms, cell physiological state, cell concentration, etc. For killing a specific strain, increasing the sterilization temperature can shorten the heating time, reducing the temperature needs to extend the heating time, and the temperature is too low, it will not have the sterilization effect on some heat-resistant strains.
Hot water spray sterilization is to use the nozzle to spray hot water in multiple directions to the bottle cap, and remove the dust on the inside and outside of the bottle cap while carrying out sterilization. In the process of production, the bottle cap after capping travels in the same direction in the bottle cap channel, and multiple groups of nozzles are arranged on the upper and lower parts of the channel. The nozzle carries out multi-directional hot water spraying on the advancing bottle cap. The temperature of the hot water is the sterilization temperature, and the time of receiving the spraying is the sterilization time.
Due to its high temperature resistance, the hot water temperature of the spray can exceed 85℃, and the spray time can be reduced with the increase of the hot water temperature; For plastic bottle caps, the hot water temperature is generally controlled at 85 ° C. After hot water sterilization, it is necessary to spray sterile air on the bottle cap to promote the drying of the bottle cap.
Hot water injection sterilization needs to provide hot water and sterile air, need the corresponding supporting equipment, production will consume heat energy and a small amount of water resources, for its supporting is commonly used general equipment. Hot water spray sterilization can be used for the bottle cap treatment of tea drinks and juice drinks in high temperature filling, and can also be used for the bottle cap sterilization of mineral water. Ozone sterilization
Ozone has a strong oxidizing property, which can directly destroy the ribonucleic acid or deoxynucleic acid of the virus and kill it. Ozone can also damage the cell membrane of bacteria and mold microorganisms, inhibit their growth, and further penetrate and destroy the membrane tissues until the death of bacteria and mold microorganisms. Ozone is dissolved in water, the sterilization effect is very good in a high humidity environment, and ozone water can also be used to sterilize the bottle cap.
Ozone water sterilization will be discussed later. The greater the concentration of ozone, the better the bactericidal effect, when the ozone concentration is 4.0mg/m3, the bactericidal time generally takes 45 minutes to 1 hour.
Because ozone sterilization takes a long time, for an automated beverage production line with a certain production capacity, if you want to meet the sterilization effect and let the bottle cap sterilization process be completed continuously in the sterilization equipment, the sterilization equipment needs to be very large. In the actual production process, ozone sterilization of bottle caps is to place a certain amount of bottle caps in a larger sealed space on an automated beverage production line with a certain production capacity, and then fill the space where the bottle caps are located with a certain concentration of ozone and maintain it for a period of time. The number of caps placed depends on the number of caps needed to maintain production. The longer the sterilized bottle cap is stored, the greater the risk of contamination, so the general storage time is not more than a week. The sterilized bottle cap needs to be isolated from the outside world and sent to the cap conveying machine when the cap conveying machine needs the cap.
At present, independent equipment that directly uses ozone sterilization is mostly found in small cabinet bottle cap sterilization cabinets. The sterilization space of the bottle cap sterilization cabinet is small, the production capacity is small, the interval production is not automatic. When using this kind of ozone sterilization cabinet, it is necessary to manually move the sterilization bottle cap out of the sterilization cabinet into the capping machine, which is easy 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. Water sterilization
There are unstable elements in the bactericidal water, which will break down on their own. Water sterilization is the use of this decomposition process (oxidation process) to oxidize microorganisms on the surface of the object, so as to achieve the purpose of sterilization.
Common substances with strong oxidation are: peracetic acid, ozone water and chlorine water, ozone is better than chlorine instantaneous bactericidal properties.
At present, the sterilization water of beverage bottle caps is basically peracetic acid and ozone water, most of which are peracetic acid. The greater the concentration of sterilization water, the shorter the sterilization time required. For peracetic acid at 65℃, 2000PPM, the bottle cap can meet the requirements of commercial sterility through 30 seconds to 60 seconds of sterilization. Due to the short sterilization time and good sterilization effect of sterilization water, it is widely used in the bottle and lid sterilization of fruit and vegetable juice drinks. The main ways of sterilizing beverage bottle caps with sterilizing water are spray type and soak type.
1. The spray type is to use multiple groups of nozzles to spray sterilization water in multiple directions of the bottle cap to sterilize the surface of the bottle cap, and the time for the bottle cap to accept the spray should ensure that the microorganisms can be completely killed.
The specific method is: after the cap is arranged, the direction of the cap enters the cap track in the same way, and a number of groups of nozzles are provided on the top and bottom of the track, each group of nozzles can spray sterilization water on the cap from different angles, and the spray sterilization water both sterilizes the cap and pushes the cap along the track.
When peracetic acid is used as bactericidal water, the bottle cap should be rinsed with sterile water to remove the residual peracetic acid on the bottle cap, so that the residual amount is lower than the relevant standard; Rinse with sterile water and blow dry the cap with sterile air.
When using ozone water as sterilization water, because the product of ozone water decomposition is water and oxygen, there is no harmful residual substances, in theory, there is no need to treat the bottle cap again, but in the actual production process, because the bottle cap sterilization machine is close to the capping machine, the residual ozone can not be completely decomposed, so, After sterilization with ozone water, the bottle cap also needs to be washed with sterile water and dried with sterile air. Due to the straightness of the spray water, sterile water spray sterilization can be used for mineral water bottle cap sterilization, and can also be used for tea drinks and juice drinks hot filling bottle cap sterilization. Hot filling adopts full bottle filling. After filling and capping, pour bottle to heat bottle cap and carry out internal sterilization treatment.
2. The soaking type is to completely soak the beverage bottle cap in the bactericidal water, so that all the inner and outer surfaces of the bottle cap are bactericidal water sterilization, and the soaking time should meet the time requirements of the bottle cap for complete sterilization. One method is: the bottle cap in the same direction is fixed on the bottle cap rack, the bottle cap rack is connected to the chain, the movement of the chain drives the bottle cap rack into the sterilization tank with sterilization water and the bottle cap is completely immersed in the sterilization water, the soaking time should meet the time requirements of complete sterilization. As with the spray sterilization method, the bottle cap after sterilization water immersion also needs to be sprayed with sterile water and sterile air, so that the bottle cap is dry and sterile. When sterile water sterilization is used, the supporting sterilization water, sterile water and sterile air need to be produced and treated, and the peripheral supporting equipment is more, the supporting cost is high, the consumption cost is large, and the management requirements are high, so this sterilization process is generally applied to the aseptic cold filling of juice drinks.
Electrolyte sterilization
Electrolysis is the use of inert electrodes in the liquid electricity, the anode oxidation reaction, the cathode reduction reaction. At present, the relevant foreign personnel have studied the use of completely desalted drinking water and sodium chloride dilute solution of electrochemical reaction, in the anode area to obtain the bactericidal effect of traditional bactericidal water. If the principle of electrolysis is directly used for bottle cap sterilization, it can greatly reduce transportation and storage costs, save time and effort, and be safe and effective.