Discussion on the safety and hygiene of food packaging barrels

Discussion on the safety and hygiene of food packaging barrels

In recent years, the export volume of agricultural and sideline products in China has increased year by year. Mainly due to the influence of climatic conditions, China's agricultural and sideline products, especially in the west of honey, apples, tomatoes, etc., its honey and tomatoes are rich in vitamins and sugar, apple juice contains more sugar than other parts of the country. To this end, the amount of agricultural and sideline products exported to the west has increased year by year. According to market research, next year, China's agricultural and sideline products production base will invest huge sums of money to introduce 7~8 tomato processing production lines and 5~6 apple processing production lines. For this purpose, the amount of metal packaging barrels for ketchup and juice is used. It will also increase by more than 1 million on the basis of this year; however, due to the backward level of deep processing technology in the west, most of the exported products need to be transported to Qinhuangdao, Shandong and other places for further processing. In order to reduce costs, suppliers have adopted the steel drums coated with food coatings for packaging and transportation before domestic deep processing, so it is very important to ensure the quality of the inner wall of the inner steel drums. Moreover, in this year's production and operation activities, some distributors have begun to ask the metal packaging enterprises for the production of sanitary safety licenses for metal packaging drums. To this end, the authors called on metal packaging companies to pass the food safety and hygiene permit acceptance and inspection as soon as possible before the harvest season of agricultural and sideline products, to prepare for the sales of food barrels next year.

This year, due to the relaxation of the import conditions of agricultural and sideline products in Europe and the United States, coupled with the recent years, China has also spent a lot of energy on the production and processing of agricultural and sideline products. The pesticide content of honey, tomato and apple has been effectively controlled, and its export volume has obviously made a great breakthrough on the basis of the past. In the past, China did not have a national standard for the identification of honey. The honey exported was sent to foreign countries first, and then exported after being qualified. However, this will delay the opportunity and be hindered by foreign technical barriers, thus seriously affecting China's honey. The export and development of the bee industry. In the past few years, through the efforts of Qinhuangdao Quality and Technical Supervision Bureau, 25 inspection standards for honey products have been formulated and won praises from Germany and other countries. Due to the inspection standards, the technical barriers to the honey we export in the future will be mastered by ourselves, and the export volume will increase greatly. It is hoped that bee merchants, beekeepers, fruit farmers, tomato planting and processing enterprises, and their packaging and production enterprises should be prepared in advance to meet new challenges.

The inner coated steel drums currently used for foods generally include: honey buckets, juice buckets, and ketchup buckets. If the inner coating drum used for these foods does not meet the safety food hygiene requirements due to the sanitary quality of the inner wall coating, it will cause secondary pollution, which will affect the inherent quality of the product. Let's talk about some common food interior coatings.

The food coatings allowed to be used on the inner wall of steel drums in China include: polyamide epoxy resin coatings, peroxyethylene coatings, and organic fluorine coatings. Let us discuss the food safety and hygiene requirements of these internal coatings.

1. Hygienic requirements for polyamide epoxy resin coatings

Polyamide epoxy coatings are epoxy based coatings. Epoxy resin coatings are cured film forming coatings. The epoxy resin is generally formed by polymerizing bisphenol A (diphenol propane) and epichlorohydrin. Depending on the degree of polymerization, the molecular weight of the epoxy resin is also different. From the hygienic angle, the larger the molecular weight (that is, the smaller the epoxy value), the more stable, and the less likely the harmful substances are dissolved and migrated into the food, so the safety is higher.

As a curing agent for polyamide oxyresin coatings, polyamide itself is a high molecular weight compound, and no toxicity has been reported. The quality of the polyamide epoxy resin (epoxy value of the epoxy resin), the ratio of the curing agent, and the degree of curing. The curing agent ratio is appropriate, and the higher the degree of curing, the less uncured material migrates into the food in the epoxy resin coating. According to the provisions of GB9686-88 "Sanitary Standard for Polyamide Epoxy Resin Coatings on Inner Walls of Food Containers", the evaporation residue of polyamide epoxy resin coatings in various solvents should be controlled below 30mg/l.

Second, the hygienic requirements of perchloroethylene coatings

The perchloroethylene coating is made of perchloroethylene resin and is mixed with a plasticizer. After being coated or sprayed on the inner wall of the steel drum, it is naturally dried to form a film. Perchloroethylene coatings are generally classified into primers and topcoats. The perchloroethylene resin contains a vinyl chloride monomer, which is a carcinogenic toxic compound. The perchloroethylene coating after film formation may still contain residual vinyl chloride. According to the provisions of GB7105-86 "Sanitary Standard for Perfluoroethylene Inner Wall Coatings for Food Containers", the residual vinyl chloride monomer in the perchloroethylene coating after film formation shall be Controlled below 1mg/kg. Additives such as plasticizers and solvents used in perchloroethylene coatings must comply with the relevant provisions of GB9685-94 "Sanitary Standards for Auxiliaries for Food Containers and Packaging Materials". Do not use highly toxic or highly toxic additives. The coating film should be uniform, free of bubbles, spots, wrinkles, and shedding.

Third, the sanitary requirements of organic fluorine coatings

Organic fluorine coatings include polyvinyl fluoride, polytetrafluoroethylene, and polyhexafluoropropylene coatings. These coatings are polymerized with vinyl fluoride, tetrafluoroethylene, and hexafluoropropylene as the main raw materials, and are coated with certain additives to be sprayed in steel drums. The inner wall surface. Organic fluorine coatings have the characteristics of anti-adhesion and corrosion resistance, but their acid resistance is poor. Therefore, it is widely used in inner coated steel drums containing honey. The specific application of the organic fluorine coating on the inner coated steel drum is polytetrafluoroethylene, referred to as PVF coating. It is a kind of polymer compound, chemically stable, and generally does not have monomer residue. It is a safer food packaging steel drum inner wall coating. However, since the Teflon coating requires a higher degree of cleaning of the coated steel drum, the steel drum is usually cleaned before being sprayed. When cleaning the inner wall of steel drums, most steel drum manufacturers use spray cleaning and drying lines for cleaning. The cleaning agent is usually chromate, which may cause the chromium salt to remain on the surface of the steel drum and then be mixed into the inner coating. Therefore, in the production of honey barrels, the inner coated honey barrels should be inspected in accordance with the provisions of GB1167-89 "Sanitary Standards for Teflon Coatings on the Inner Wall of Food Containers". The standard stipulates that the appropriate amount of chromium and fluorine should be controlled below 0.01 mg/l and 0.2 mg/l, respectively. In addition, when PTFE is baked, if the temperature reaches 280 ° C, fission will occur, resulting in highly volatile toxic fluoride. Therefore, the baking temperature should not be generally used when coating the honey barrel with Teflon. More than 250 ° C.

Through the above introduction, we can see that the food coating applied to the inner wall of the packaged food steel drum, if not handled properly, is not strictly controlled according to the process requirements, more or less will have residues to migrate to the coating coating, thus polluting The food inside. As a food packaging, it must meet the safety and hygiene standards of food, which is the most basic common sense. In recent years, the juice, ketchup and honey exported by China have always been unable to obtain entry qualifications because of the excessive pesticide content, and even after being placed at the port for a long time, they are eventually returned to the domestic embarrassing situation. Therefore, as food packaging, in addition to meeting the basic requirements of food hygiene, it is also necessary to require that the residual amount of solvent should be as low as possible. This requires that the manufacturers of food packaging steel drums must comply with food safety and hygiene requirements when making barrels for food production, to ensure that the cleaning and residual harmful substances of steel drums do not exceed the hygiene standards; in order to ensure the quality of food coatings, steel The barrel manufacturer should regularly obtain the production license issued by the local quality inspection department and the effective food safety and hygiene inspection report from the food coating supplier. The quality and technical supervision department shall also regularly supervise and inspect the steel drums inside the food, and issue inspection reports; the customers of the food inner coating drums must also obtain the production license issued by the superior quality inspection part from the manufacturer of the packaging steel drums. And an effective food safety and hygiene inspection report.