CN111956818A - Blue light disinfection and cleaning method for ring-pull tab of pop-top can - Google Patents

Abstract

The invention discloses a blue light disinfection and cleaning method at the pull ring of a pop-top can, belonging to the technical field of food safety packaging and sterilization. The blue light disinfection and cleaning method at the pull ring of a pop can according to the present invention comprises the following steps: (1) performing blue light irradiation at the pull ring of the pop can; wherein, the dose of blue light irradiation is not less than 5J/cm ² ; (2) After the irradiation is completed, the aseptic protective film is applied to the pull tab of the can irradiated with blue light in step (1) by using an adhesive. The present invention uses blue light to irradiate the normally placed can pull ring, non-specifically kills the contaminated bacteria at the pull ring of the can, and ensures that the pull ring is in a sterile state, and at the same time ensures that the can body itself is not adversely affected, and the protective film is pasted. , to ensure that the pull ring has been in a sterile state, and to ensure the safety of consumers.

Description

A blue light disinfection and cleaning method at the pull ring of a pop-top can

technical field

The invention relates to a blue light disinfection and cleaning method at a pull ring of a pop-top can, belonging to the technical field of food safety packaging and sterilization.

Background technique

The pop-top can is the most common metal beverage container in life. It can be used to hold various beverages, beer, herbal tea, coffee, porridge, etc. The pop-top can has the advantages of convenient transportation, convenient refrigeration, good structural strength, and not easy to break. The foundation of the beverage industry also plays a role in promoting the aluminum industry.

At present, the structures of cans on the market are basically the same. The main difference lies in the difference in capacity, can diameter, can height and material. When opening, it is mainly carried out through the pull ring. The pull ring structure of the existing cans is divided into built-in pull The ring structure and the flip-out pull-ring structure, but whether it is built-in or flip-out, there are hygienic problems, that is, most cans are exposed to the outside as a whole, and are easily contaminated by microorganisms during transportation and storage. Especially at the opening of the pull ring, because it is designed to be located in the groove at the top of the tank, it is more likely to be contaminated with bacteria. In recent years, there have been many reports of foodborne poisoning incidents caused by microbial contamination at the pull tab due to contact with media such as dust or insects after consumers purchase canned beverages.

The bacteria that are easy to breed at the pull tab of the can mainly include Escherichia coli, Staphylococcus aureus, Salmonella, Listeria monocytogenes, Campylobacter jejuni and Vibrio parahaemolyticus. Among them, food poisoning caused by Staphylococcus aureus is a food-borne disease caused by exotoxins or endotoxins produced in food. Food poisoning caused by Salmonella is caused by the pathogenic bacteria that can pass through the gastrointestinal mucosa and cause cell death, causing harm to the body.

The current antibacterial or sterilization methods for the contaminated bacteria at the pull tab of the can include: 1) high-temperature instantaneous sterilization technology, which has the disadvantage of easily adversely affecting the can body; 2) wiping or washing with water, which may cause unclean wiping or secondary pollution , and consumes manpower and material resources; 3) The protective agent applied to the pull ring has a certain effect, but it will cause problems such as inconvenience in refrigeration or easy to bring into the mouth of consumers, and the cost is high.

In view of these problems, it is urgent to develop a new sterilization method for the pull tab of the can, which has the following characteristics: 1) non-specific sterilization; 2) will not cause harm to the quality and safety of the pull tab of the can, and will not affect the color of the food in the can The fragrance has a negative impact; 3) The operation is safe, the method is simple, and the equipment requirements are not high.

SUMMARY OF THE INVENTION

In order to solve at least one of the above problems, the present invention provides a blue light disinfection and cleaning method at the pull ring of a can. The blue light of a specific wavelength (462-480nm) is used for sterilization and curing and sealing operations to sterilize the pull tabs of the pop-top cans and maintain the sterile state; it provides guarantee for the subsequent storage and transportation of the pop-top can food until the safety of consumers.

The first object of the present invention is to provide a blue light disinfection and cleaning method at the pull ring of a can, comprising the steps:

(1) blue light irradiation is carried out at the pull ring of the can; wherein, the dose of blue light irradiation is not less than 5J/cm ² ;

(2) After the irradiation is completed, the sterile protective film is pasted to the pull ring of the can irradiated with blue light in step (1) by using an adhesive.

In an embodiment of the present invention, the can is a can at room temperature or refrigerated.

In an embodiment of the present invention, the wavelength of the blue light is 462-480 nm.

In an embodiment of the present invention, the irradiation dose of the blue light is 5-20 J/cm ² .

In an embodiment of the present invention, the light source of blue light includes an LED lamp or a fluorescent lamp.

In an embodiment of the present invention, the pull tab of the can refers to a circular area of 2 cm around the mouth of the pull tab.

In one embodiment of the present invention, the binder is a blue light curing binder that uses blue light waves as an energy source to realize the curing of the polymerization system through chemical reactions of excited molecules.

In an embodiment of the present invention, the blue light curing parameters of the adhesive are: the blue light wavelength is 430-485 nm, and the curing time is 60 seconds.

In one embodiment of the present invention, the binder is poly(glyceryl sebacate).

In an embodiment of the present invention, the sterile protective film is a PET film, which is transparent and has a thickness of 0.1 mm-0.25 mm.

In an embodiment of the present invention, the cans may be cans for beverages, beer, herbal tea, coffee, and porridge.

Beneficial effects of the present invention:

(1) By 462-480nm blue light irradiation, all kinds of polluting bacteria at the pull ring of the can can be killed, because the blue light stimulates the free porphyrin substances in the bacteria to produce peroxides, damages the bacterial cell membrane structure, and causes the bacteria to die. Short processing times, high efficiency, and no unpleasant gas generation and no damage to cans.

(2) The can body of the can can be refrigerated at low temperature or at room temperature. The sterilization operation process has no requirements for its placement environment and does not harm the safety of the operator.

(3) The sticking of the protective film on the pull tab after the blue light irradiation ensures the aseptic state of the subsequent can pull tab during transportation and storage.

(4) Using blue light wave as the energy source, the curing of the polymerization system is realized through the chemical reaction of the excited state molecules, and the protective film is pasted at the pull ring, which has fast curing, convenient sizing, short time, high bonding strength, and Small adjustments are easy to implement.

(5) The binder polyglyceryl sebacate is a hydrophobic polymer with good biocompatibility and biodegradability, which is safe and harmless to human body.

(6) The protective film is made of PET. PET is a copolymer of polyester. It has the characteristics of high hardness, high transparency and high temperature resistance. The adhesive surface can be glued or electrostatically charged. It is the best protection at present. Membrane raw materials are widely used in many fields.

(7) The present invention irradiates the normally placed can tab of the can by blue light, non-specifically kills the polluting bacteria at the tab of the can, and ensures that the tab is in a sterile state, and at the same time ensures that the can body itself does not have adverse effects, and protects the can body itself. The sticking of the film ensures that the pull ring is always in a sterile state and ensures the food safety of consumers.

Detailed ways

The preferred embodiments of the present invention will be described below, and it should be understood that the embodiments are used to better explain the present invention and are not intended to limit the present invention.

Example 1: Blue light disinfection and curing of cola and beer cans

Dispose of cans as follows:

(1) Buy two kinds of can drinks (36 cans of Coca-Cola cans and 36 cans of Suntory beer cans) from a small retail supermarket in Wuxi City, Jiangsu Province, first place 18 cans of cola cans and 18 cans of beer cans at room temperature for 30 minutes, and use an alcohol cotton swab to Wipe and sterilize the 3 cm area around the pull ring, and then inoculate 0.1 mL of mixed microbial bacteria solution (containing 1 × 10 ⁶ /mL Salmonella, 1 × 10 ⁶ / mL of Staphylococcus aureus, which is also the main contaminating bacteria in the transportation process), placed to dry, and then 3 cans of cola cans and 3 cans of beer cans were taken as a group, and they were divided into 6 groups at room temperature.

The other 18 cans of cola cans and 18 cans of beer cans were placed in the refrigerator at 4°C for 30 minutes, wiped with an alcohol cotton swab, inoculated with the same bacterial solution, placed to dry, and then divided into 6 groups, that is, 6 groups of refrigerated storage. The following operations were performed in the room temperature group and the refrigerated group, respectively.

(2) Take 6 groups at room temperature and irradiate with blue light respectively, place the 462nm blue LED light above the pull ring of the can, at a distance of about 10cm, and control different times so that the light doses are respectively: the first group 0J/cm ² , the second group 1.25J/cm ² , the third group 2.5J/cm ² , the fourth group irradiation 5J/cm ² , the fifth group 10J/cm ² and the sixth group 20J/cm ² ;

The blue light irradiation operation of the 6 groups at refrigeration was the same as that of the 6 groups at room temperature, but the irradiation process was carried out in a freezer to ensure the maintenance of the temperature.

(3) After the irradiation, paste the sterile protective film PET film (transparent, thickness 0.25mm) on the circular area of 2 cm around the ring that receives the blue light irradiation, and then irradiate it through the blue light curing machine (blue light wavelength 430- 485nm, irradiation time 60 seconds), to make the PET film and the pop-top can be tightly bonded.

After the blue light irradiation, 6 groups of samples were kept at room temperature for 30 days, and 6 groups of samples were refrigerated and stored in a refrigerator at 4°C for 30 days, and then the film was peeled off and sealed, and the following operations and tests were performed:

Hold the sterile cotton ball with tweezers and wipe the pull ring at the mouth of the tank; then, spread the substance attached to the sterile cotton ball evenly on the medium of the flat plate culture dish, and place the culture dish at 37 ℃. In a constant temperature incubator at ℃, after culturing for 24 hours, the sterilization rate of contaminated bacteria was calculated with reference to GB 4789.2-2010 Food Microbiology Inspection; the obtained data were the average value of three repetitions.

The test results of the sterilization rate are shown in Table 1. It can be seen from Table 1 that: after 462nm blue light irradiation, the second group 1.25J/cm ² and the third group 2.5J/cm ² , the sterilization rate is lower than 40%, and the sterilization effect The sterilization efficiency increased significantly from the fourth group, all higher than 95%, so the minimum irradiation dose was selected to be 5J/cm ² . It can be seen that blue light irradiation and aseptic protective film sticking have a significant synergistic effect, which can significantly improve the sterilization and fresh-keeping effect at the pull ring of cans.

Table 1 Bactericidal efficiency of blue light irradiation on harmful bacteria in cola and beer cans

Example 2 Optimization of wavelength

The blue light irradiation wavelength of the fourth group at room temperature (the fourth group irradiated 5J/cm ² ) in Example 1 was adjusted to 400nm, 415nm, 440nm, 460nm, 462nm, 475nm, 480nm; the others were kept with the fourth group at room temperature in Example 1 constant.

The sterilization effect is shown in Table 2. It can be seen from Table 2 that the sterilization efficiencies of the three wavelengths of 462nm, 475nm and 480nm are all higher than 95%, and the sterilization effect is remarkable, while the sterilization efficiencies of the 400nm, 415nm, 440nm and 460nm wavelengths are all lower than 60%. The bactericidal effect is low, so the 462-480nm range has obvious bactericidal effect on the diverse polluting bacteria in nature.

Table 2 Comparison of sterilization efficiency of different wavelengths of blue light on harmful bacteria in cola and beer cans

Comparative Example 1

Buy two cans of beverages (3 cans of Coca-Cola cans, 3 cans of Suntory beer cans) from a small retail supermarket in Wuxi City, Jiangsu Province, first place the cola cans and beer cans at room temperature for 30 minutes, and use an alcohol cotton swab to rub the 3-cm cans around the pull ring. The area was wiped and sterilized, and then 0.1 mL of mixed microbial bacterial solution (containing 1×10 ⁶ /mL Salmonella, 1×10 ⁶ /mL Staphylococcus aureus) was inoculated in a 2 cm circular area around the pull ring of the can. Dry, and then place the 462nm blue LED light above the pull tab of the cans at room temperature, at a distance of about 10cm, and control the time so that the light dose is 5J/cm ² , and PET film does not need to be pasted.

Comparative Example 2

Buy two cans of beverages (3 cans of cola cans, 3 cans of beer cans) from a small retail supermarket in Wuxi City, Jiangsu Province, first place the cola cans and beer cans at room temperature for 30min, and use an alcohol cotton swab The area was wiped and sterilized, and then 0.1 mL of mixed microbial bacterial solution (containing 1×10 ⁶ /mL Salmonella, 1×10 ⁶ /mL Staphylococcus aureus) was inoculated in a 2 cm circular area around the pull ring of the can. Dry, then paste the protective film PET film according to the step (3) of Example 1 for curing (the sterile protective film PET film (transparent, thickness 0.25mm) is attached to the circular area of 2 cm around the pull ring of the receiving can, Then irradiate and cure through a blue light curing machine (blue light wavelength 430-485nm, irradiation time 60 seconds), so that the PET film and the cans are tightly bonded).

The samples of Comparative Example 1 and Comparative Example 2 were kept at room temperature for 30 days.

The samples of Comparative Examples 1 and 2 are tested for bactericidal effect (the method is the same as that of Example 1), and the test results are shown in Table 3. The sterilization efficiency of the treatment method of Comparative Example 1 is extremely low, which is likely to be polluted by microorganisms in the environment after sterilization. , while the treatment method of Control Example 2 has almost no sterilization effect, while Example 1 combines the two operations of Control Example 1 and Control Example 2, combining sterilization and maintaining aseptic state to achieve sterilization and preservation of cans.

Table 3 Comparison of the sterilization efficiency of different blue light treatment methods on the harmful bacteria of cola and beer cans

Comparative Example 3

The PET films of the fourth group at room temperature (the fourth group irradiated at 5 J/cm ² ) in Example 1 were adjusted to PP films and PVC films, and the others remained unchanged from those of Example 1.

The test results are shown in Table 4. It can be seen from Table 4 that the PET material has the best effect, good sealing performance and good food safety.

Table 4 Comparison of sealing effects of cans with different sealing film materials

Comparative Example 4

The adhesives of the fourth group at room temperature in Example 1 (the fourth group irradiated at 5 J/cm ² ) were adjusted to methacrylate adhesives, acrylic pressure-sensitive adhesives, camphorquinone, and others were kept the same as in Example 1. Change.

The test results are shown in Table 5. It can be seen from Table 5 that among the 4 common curing agents, poly(glycerol sebacate) has the best effect and is well sealed. It is a kind of good biocompatibility and biodegradation. The hydrophobic polymer is safe and harmless to human body.

Table 5 Comparison of the sealing effect of cans with different adhesives

Example 3 Blue light disinfection and curing of fruit juice and herbal tea cans

Dispose of cans as follows:

(1) Purchase 2 kinds of canned drinks from a large supermarket in Wuxi City, Jiangsu Province, namely canned juice and canned herbal tea (specifically, 36 cans of fruit juice cans and 36 cans of herbal tea cans), 18 cans of juice cans and 18 cans of herbal tea Put the cans at room temperature for 30 minutes, wipe and sterilize the 3 cm area around the pull ring with an alcohol cotton swab, and then take 3 cans of juice cans and 3 cans of herbal tea cans as a group, divided into 6 groups at room temperature, and the other part 4 ℃ refrigerated storage is also divided into 6 groups, that is, 6 groups of refrigerated storage. Similar to Example 1, inoculate 0.1 mL of mixed microbial bacterial solution (containing 1×10 ⁶ /mL Salmonella, 1×10 ⁶ /mL Staphylococcus aureus, 1×10 ⁶ /mL Candida albicans), drained.

Other blue light sterilization and curing bonding operations and analysis methods are the same as in Example 1.

As shown in Table 6, after blue light irradiation and pasting the protective film PET film, whether it is placed at room temperature or refrigerated at 4 °C (30 days), the sterilization rates of the second and third groups are lower than 50%, and the disinfection effect is not significant. The sterilization rates in the fourth, fifth and sixth groups were higher than 97%, respectively, and the sterilization effect was very good, ensuring the healthy consumption of consumers. In addition, the blue light treatment had no effect on the appearance of the cans, and there was no significant difference (p≤0.05) compared with before irradiation, and no unpleasant odor was produced during the irradiation process, which did not affect the health of consumers and the quality of the food in the can.

At the same time, three blue light treatment methods (sterilization and curing, only sterilization, and only curing) were compared, and it was found that sterilization and curing was an effective way to sterilize and ensure long-term aseptic state.

In addition, the comparison of different sealing film materials and adhesives also shows that the use of PET film with poly(glyceryl sebacate) has the best effect. status to ensure consumer safety.

Table 6 Bactericidal efficiency of blue light irradiation on harmful bacteria in juice and herbal tea cans

Example 4 Blue light disinfection and curing of rice wine and pork floss cans

Buy rice wine and pork floss cans with different blue light doses: the first group 0J/cm ² , the second group 3J/cm ² , the third group 6J/cm ² , the fourth group 12J/cm ² , the fifth group 24J/cm cm ² . Similar to Example 1, inoculate 0.1 mL of mixed microbial bacterial solution (containing 1 × 10 ⁶ /mL Pseudomonas aeruginosa, 1 × 10 ⁶ /mL golden yellow Staphylococcus, 1 × 10 ⁶ /ml Aspergillus flavus spores. These three bacteria are the main contaminating bacteria found in the analysis of rice wine and pork floss cans). Other operations are the same as in Example 1.

The results are shown in Table 7. It can be seen from Table 7 that after blue light irradiation, the sterilization rate of 3J/ ^cm2 in the second group is lower, and the 6J/ ^cm2 in the third group is increased to 95%, which can effectively prevent food-borne diseases. bacterial contamination, with better results.

Similarly, this embodiment also reveals that 462-480nm blue light is used for sterilization, and then the ET film and poly(glyceryl sebacate) are cured and bonded to the pull-tab, which can keep the pull-loop in a sterile state for a long time, which is beneficial to consumption. health.

Table 7 Comparison of bactericidal efficiency of contaminating bacteria in rice wine and pork floss cans by blue light irradiation

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone who is familiar with this technology can make various changes and modifications without departing from the technology and scope of the present invention. Therefore, The protection scope of the present invention should be defined by the claims.

Claims (10)

1. a blue light sterilization and cleaning method at the pull ring place of a pop-top can, is characterized in that, comprises the steps: (1) blue light irradiation is carried out at the pull ring of the can; wherein, the dose of blue light irradiation is not less than 5J/cm ² ; (2) After the irradiation is completed, the sterile protective film is pasted to the pull ring of the can irradiated with blue light in step (1) by using an adhesive. 2 . The method according to claim 1 , wherein the pop-top can is a pop-top can treated at room temperature or refrigerated. 3 . 3. The method according to claim 1, wherein the wavelength of the blue light is 462-480 nm. 4. The method according to claim 1, wherein the dose of the blue light irradiation is 5-20 J/cm ² . 5. The method of claim 1, wherein the light source of blue light comprises an LED lamp or a fluorescent lamp. 6 . The method according to claim 1 , wherein the pull tab of the can refers to a circular area of 2 cm around the mouth of the pull tab. 7 . 7 . The method according to claim 1 , wherein the binder is a blue light curing binder that uses blue light waves as an energy source to realize the curing of the polymerization system through chemical reactions of excited molecules. 8 . 8. The method of claim 1, wherein the binder is poly(glycerol sebacate). 9. The method according to claim 1, wherein the sterile protective film is a PET film. 10. The method according to claim 1, wherein the cans can be cans for beverages, beer, herbal tea, coffee, and porridge.