Technical requirements and methods for tea packaging

Tea is a kind of daily drink people like. Its variety is many, common are green tea, flower tea, brick tea, white tea, oolong tea, tea and instant tea and so on. Each type of tea is divided into several varieties of flowers. Differences in its type, variety, and color have formed different characteristics. The so-called different types and different varieties of flowers and colors, mainly in the processing process used in different technical conditions, the products produced have their own type, the characteristics of the varieties. Black tea is a fully-fermented tea. Semi-fermented tea is oolong tea. Non-fermented tea is green tea. Flower tea is a tea made by the scenting process, and tea made of withering is white tea. Pressing tea is to compress the product. In order to achieve long-term storage, tea leaves also need to be packaged.
Tea packaging requirements and techniques Green tea contains mainly components such as ascorbic acid, tannic acid, polyphenol compounds, catechin fat, and carotenoids. These components are easily degraded by oxygen, temperature, humidity, light and environmental factors. Therefore, when packaging tea, the influence of the above factors should be reduced or prevented. There are specific requirements in the following aspects:
The moisture content of moisture-proof tea should not exceed 5%, and 3% is the best for long-term preservation; otherwise, the ascorbic acid in tea will be easily decomposed, and the color, fragrance and taste of tea will change, especially at higher levels. At temperature, the deterioration will accelerate. Therefore, in the packaging, moisture-proof packaging can be selected with good moisture-proof packaging materials, such as aluminum foil or aluminum foil evaporation film-based composite film, can be highly moisture-proof. Black tea packaging should pay special attention to moisture treatment.
The oxygen content in the oxidation-resistant packaging must be controlled below 1%, and too much oxygen will cause oxidation and deterioration of certain components in the tea. For example, ascorbic acid is easily oxidized into deoxy ascorbic acid, and further reacts with amino acids to cause a pigment reaction, which deteriorates the taste of tea. Because tea fat contains a considerable amount of unsaturated fatty acids, this unsaturated fatty acid can be automatically oxidized to produce aldehyde compounds such as aldehydes and ketones, as well as enol compounds, which can also make the fragrance in the tea disappear, the astringent taste fades, and the color becomes dark. In terms of packaging technology, the vacuum packaging method or the inflation packaging method can be used to reduce the presence of oxygen. The vacuum packaging is to put the tea into a soft airtight film packaging bag, and the bag is vacuumed and then sealed. If air-packed, it should be filled with nitrogen while pumping air. The purpose of nitrogen-filled packaging is to protect the color, aroma, and taste of tea leaves and maintain its original quality. Inflatable packaging has relatively strict requirements on materials, mainly in the following aspects: non-toxic, no odor (including odor of printing inks, solvents, and adhesives); good airtightness, low oxygen permeability, moisture resistance, and sufficient mechanical strength And puncture-resistant performance; good heat sealing performance; good shading performance.
After being inflated and packaged, the tea leaves can be stored for more than 2 years, which will basically not change the original quality indicators of tea. In addition, encapsulated deoxidizer packaging technology can also be used. The deoxidizer can utilize the oxidation reaction of iron and iron compounds or the oxidation reaction of sugar and reductones. The deoxidizer chemically reacts with oxygen to make the packaging container in a state of low oxygen. . When using a deoxidizer, the base material of the composite film used is preferably a vinylidene chloride coating.
Light-blocking properties Because tea leaves contain chlorophyll and other substances, when the tea is packaged, it must be shaded to prevent the photocatalytic reaction between chlorophyll and other components. In addition, ultraviolet light is also an important factor causing the deterioration of tea. Solve this type of problem can use shading packaging technology. Since most plastic films have a light transmittance of 80% to 90%, in order to reduce the transmittance, an ultraviolet ray inhibitor may be added to the packaging material or light transmittance may be reduced by printing or coloring. In addition, a composite material based on aluminum foil or vacuum aluminized film may be used for shading packaging.
The smell of gas-barrier tea is easily lost and must be sealed with a good airtight material. In addition, tea can easily absorb the odor of the outside world, so that the smell of tea is infected. Therefore, the odor produced by the packaging materials and packaging technology should be strictly controlled.
Anti-high temperature temperature will speed up the oxidation reaction of tea and cause the surface of tea to fade. Therefore, tea leaves are suitable for preservation at low temperatures.
Tea packaging methods Tea packaging should be designed according to its packaging requirements. Common packaging methods include the following.
Metal cans The metal cans are made of tin-plated steel sheet. The cans have a square and a cylindrical shape. They are covered with a single lid and a double lid. From the seal up, there are two kinds of general cans and sealed cans. The general tank is sealed with a deoxidizer to remove oxygen from the package. Sealed cans are mostly used for inflation and vacuum packaging. Metal cans are superior to composite films in the protection of tea and are beautiful and noble.
Composite film bag packaging Currently, more and more commercially available tea packaging using composite film bag packaging. There are many types of composite films for packaging tea, such as moisture-proof cellophane/polyethylene/paper/aluminum foil/polyethylene, biaxially oriented polypropylene/aluminum foil/polyethylene, polyethylene/polyvinylidene chloride/polyethylene, and composite films. Has excellent gas barrier, moisture resistance, fragrant, anti-odor and so on. The composite film with aluminum foil has superior performance, such as excellent shading. Composite film bags are available in a variety of formats, including three-side seals, stand-up pouches, and folds. In addition, the composite film bag has a good printability, and its use as a sales packaging design will have unique effects.
The plastic molding container packaging is packaged by polyethylene, polypropylene, polyvinyl chloride, and other molding containers. Because of its poor sealing performance, it is mostly used as an external packaging, and its packaging is mostly packaged in plastic bags. The plastic molding container is generous and beautiful, and the display effect is good.
Lined bag boxes use cardboard with inner layer of plastic film or coated with moisture-proof paint to make packaging boxes for packaging materials. This package has both the function of composite film bag packaging and the protection and rigidity of carton packaging. performance. If a small bag is made of plastic bags inside, the protection is better.
Paper Bag Packaging This is a kind of bag packaging made of thin filter paper. It is usually called teabag and it is put into the tea set when it is used. Early bags of tea bags were lined with bags to meet the convenience of multiple immersions. Due to the consideration of environmental protection, bags of tea without a bag line are gradually popular. The purpose of packaging with filter paper bags is mainly to increase the leaching rate, and also to make full use of the tea plant tea.