The development of the Chinese beverage industry is very rapid. The variety of beverages has gradually developed from pure carbonated beverages to mineral water, fruit juices, fruit and vegetable juice beverages and functional beverages. The filling method has also developed from cold filling to current hot filling. , Medium temperature filling, aseptic cold filling, etc .; packaging forms also range from single glass bottles to current cans, PET bottles, etc. For different products and different packaging forms, the sterilization treatment of packaging bottle caps is also critical. This article discusses the various methods of sterilizing beverage bottle caps currently used.
After the microorganisms are irradiated with ultraviolet light, their proteins and nucleic acids absorb the energy of the ultraviolet spectrum, which can cause protein denaturation and cause the death of microorganisms. In beverage filling production equipment, the cap conveyer is a capping machine or a capping machine to convey bottle caps. An ultraviolet germicidal lamp tube is installed on the upper part of the capping machine storage bin or the upper part of the conveyor belt. The bottle caps are exposed to ultraviolet rays during the transportation process. The ultraviolet rays can reach a better sterilization effect. Due to the poor light transmission of the bottle cap, ultraviolet rays cannot penetrate the bottle cap and shine on the other side of the bottle cap. Therefore, the bottle cap can only achieve partial sterilization, and the surface of the sterilization is random. In order to sterilize the surface of the bottle cap in a targeted manner, an ultraviolet germicidal lamp is installed on the cap slide of the capping machine or capping machine. The bottle cap has been arranged in the same direction through the bottle cap. The side where the beverage comes into contact effectively improves the sterilization effect.
Ultraviolet sterilization equipment is simple, does not require supporting equipment, low cost, convenient operation and management, and is widely used. Due to the structural characteristics of the slideway and the killing characteristics of ultraviolet rays on microorganisms, ultraviolet rays
The sterilization method is generally suitable for use in the following types of beverage bottle filling:
1, carbonated drinks
Carbonated drinks contain CO2, which is acidic and can inhibit the growth of microorganisms.
Ultraviolet sterilization is sufficient. During the production, new bottle caps packed in batches are poured into the storage bin of the capping machine, and the bottle caps are sterilized by ultraviolet radiation in the storage bin of the capping machine or on the conveyor belt; it can also be sterilized under the capping machine An ultraviolet germicidal lamp is set on the cap chute, so that the inner surface of the bottle cap is irradiated with ultraviolet rays to sterilize, and then directly sent to the capping machine after sterilization.
2. Mineral water drink
The state has formulated relatively strict regulations for the production of mineral water, in which the total number of colonies, mold counts, and E. coli of mineral water are strictly limited to zero. Regardless of whether the mineral water has been filtered or sterilized, its total bacterial count, mold count, and E. coli count must meet national standards. Because mineral water contains only inorganic salts, does not contain microbial nutrition sources, and lacks nutrients for microbial production and development, its bottle caps can also be sterilized with ultraviolet light.
3.High-temperature filled tea drinks and fruit juice drinks
There are various microorganisms (bacteria, molds, yeasts, etc.) in tea drinks and fruit juice drinks. The sterilization of beverages is to kill these microorganisms. At present, high-temperature short-term sterilization is generally used, also known as instant sterilization. High temperature filling is to cool the beverage after instant sterilization in a temperature range between 85 ° C and 92 ° C. The beverage bottle is a crystalline heat-resistant hot filling bottle, and the bottle cap is a 85 ° C heat-resistant bottle. The cap and filling method adopts full bottle filling, and a bottle pouring device is added after filling the cap (or screwing the cap): the bottle body is poured 90 ° to 180 °, and the inside of the bottle cap is sterilized by using the high temperature of the beverage itself. Therefore, the bottle caps can also be sterilized with ultraviolet rays in the pre-treatment.
Hot water spray sterilization
Heat sterilization is one of the traditional methods of food preservation. If the microbial cells are heated to a certain temperature, physiologically active substances (such as enzyme proteins, nuclear proteins, DNA, etc.) in the cells will be denatured and inactivated, thereby losing their activity and dying. The heating temperature and time for killing microorganisms are obviously different according to the type of microorganisms, the physiological state of the cells, and the cell concentration. For killing a specific strain, increasing the sterilization temperature can shorten the heating time. Lowering the temperature requires prolonging the heating time. If the temperature is too low, the sterilization effect will not be achieved for some heat-resistant bacteria.
Hot water spray sterilization is to use nozzles to spray hot water on the bottle caps in multiple directions, and to remove the dust on the inner and outer surfaces of the bottle caps while sterilizing. During production, the caps after capping travel in the cap channel in a consistent direction. Multiple groups of nozzles are arranged above and below the channel. The nozzles spray hot water from the bottle cap in multiple directions, and the temperature of the hot water It is the sterilization temperature, and the time for spraying is the sterilization time.
Due to the high temperature resistance of metal caps, the hot water temperature of the spray can exceed 85 ° C, and the spray time can be reduced as the hot water temperature increases; for plastic bottle caps, the temperature of the hot water spray is generally controlled at 85 ° C. After hot water sterilization, the bottle cap needs to be sprayed with sterile air to promote drying of the bottle cap.
Hot water spray sterilization requires the provision of hot water and sterile air, and corresponding supporting equipment. It consumes heat energy and a small amount of water resources during production. It is usually equipped with general-purpose equipment. Hot water spray sterilization can be used to treat the caps of high-temperature filled tea drinks and fruit drinks, and it can also be used to sterilize the caps of mineral water.
Ozone has extremely strong oxidizing properties, and it can directly destroy and kill viruses' RNA or DNA. Ozone can also damage the cell membrane of bacteria and mold microorganisms, inhibit its growth, and further penetrate and destroy the tissues in the membrane until the bacteria and mold microorganisms die. Ozone dissolves in water and has a very good sterilization effect in a high humidity environment. You can also use ozone water to sterilize the bottle cap.
The ozone water sterilization will be discussed later. The greater the ozone concentration, the better the sterilization effect. When the ozone concentration is 4.0 mg / m3, the sterilization time generally takes 45 minutes to 1 hour.
Ozone sterilization takes a long time. For an automated beverage production line with a certain production capacity, if both the sterilization effect is to be satisfied and the bottle cap sterilization process is continuously completed in the sterilization equipment, the sterilization equipment needs to be very large. In the actual production process, bottle cap ozone sterilization is to place a certain amount of bottle caps in a large 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 a period of time. time. The number of caps placed depends on the number of caps required to maintain production. The longer the storage time of the sterilized bottle cap, the greater the risk of contamination, so the storage time is generally less than one week. The sterilized bottle caps need to be isolated from the outside, and will be sent to the cap conveyor when the cap conveyor needs caps.
At present, independent equipment that directly uses ozone sterilization is more common in small cabinet-type bottle cap sterilization cabinets. The bottle cap sterilization cabinet has small sterilization space, small production capacity, interval production and non-automation. When using such an ozone sterilization cabinet, it is necessary to manually remove the sterilized bottle caps from the sterilization cabinet and put them in the capping machine, which easily causes secondary pollution of the bottle caps. Therefore, ozone sterilization is only suitable for non-automated production lines or small production lines with certain sterilization requirements for bottle caps.
Unstable elements are present in the sterilizing water and they break down on their own. Sterilization water sterilization is to use 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 oxidizing properties are: peroxyacetic acid, ozone water and chlorine water. The instantaneous bactericidal properties of ozone are better than chlorine.
At present, peroxyacetic acid and ozone water are basically used as sterilizing water for sterilizing beverage bottle caps, and most of them are peroxyacetic acid. The greater the concentration of sterilizing water, the shorter the sterilizing time required. For 65 ℃ 2000PPM peroxyacetic acid, through 30 seconds to 60 seconds of sterilization, the bottle cap can reach the requirements of commercial sterility. Due to the short sterilization time and good sterilization effect of sterilization water, it is widely used for sterilization of bottles and caps of fruit and vegetable juice drinks. The methods of sterilizing beverage bottle caps with sterilizing water are mainly spray type and immersion type.
1, jet flush
Multi-group nozzles are used to spray sterilized water from multiple directions of the bottle cap to sterilize the surface of the bottle cap. The time for the bottle cap to be sprayed should ensure that the microorganisms can be completely killed.
The specific method is as follows: the direction of the cap after the capping enters the cap track uniformly, and there are multiple groups of nozzles on the upper and lower sides of the track. Each group of nozzles can spray sterilizing water on the bottle cap from different angles. Cap sterilization also pushes the cap along the track.
When using peroxyacetic acid as sterilizing water, the bottle caps after spraying with sterilizing water need to be rinsed with sterile water to remove the residual peroxyacetic acid on the bottle caps so that the residual amount is lower than the relevant standard; after washing with sterile water The caps were then dried with sterile air.
When using ozone water as sterilizing water, because the products of decomposition of ozone water are water and oxygen, there is no harmful residual substance. In theory, there is no need to treat the bottle cap again. However, in the actual production process, because the bottle cap sterilizing machine exits The distance to the capping machine is very close, and the residual ozone cannot be completely decomposed. Therefore, after the bottle cap is sterilized by ozone water, it needs to be rinsed with sterile water and dried with air. Due to the linearity of spray water, sterile water spray sterilization can be used for sterilization of mineral water bottle caps, and can also be used for sterilization of bottle caps during hot filling of tea drinks and fruit juice beverages. Hot filling adopts full bottle filling. After filling the cap, the bottle is heated and the bottle cap is heated for internal sterilization.
The beverage bottle cap is completely immersed in sterilizing water, so that all the inner and outer surfaces of the bottle cap are subjected to sterilizing water sterilization, and the soaking time should meet the time required for the bottle cap to be completely sterilized. One method is: the bottle caps in the same direction are fixed on the bottle cap holder, the bottle cap holder is connected to the chain, and the movement of the chain drives the bottle cap holder into the sterilization tank containing the sterilizing water and completely soak the cap in the sterilizing water The immersion time should meet the time requirement for complete sterilization. In the same way as spray sterilization, the bottle caps soaked with sterilized water also need to be sprayed with sterile water and sprayed with sterile air to make the caps dry and sterile.
When using the sterile water sterilization method, the supporting sterilizing water, sterile water and sterile air need to be produced and processed. There are many peripheral supporting equipment, high supporting costs, high consumption costs, and high management requirements. The process is generally used for aseptic cold filling of fruit juice beverages.
Electrolysis uses an inert electrode to energize a liquid, and the anode undergoes an oxidation reaction and the cathode undergoes a reduction reaction. At present, relevant personnel abroad have studied the use of completely demineralized drinking water to electrochemically react with a dilute solution of sodium chloride to obtain a sterilization effect in the anode area that is better than traditional sterilization water. If the principle of electrolysis is directly used to sterilize bottle caps, it can greatly reduce transportation and storage costs, save time and effort, and be safe and effective.