High fat content in cream, which is the main reason why it is prone to deterioration and contamination. It is easy to produce rancidity due to oxidation, and also easy to absorb the odor in the surrounding environment. Cream is used in glass bottles and polystyrene containers, with polyethylene / aluminum box composite material as the sealing material. The cream can also be sterilized at ultra-high temperature and sterilised. In daily sales, most of the cream is packaged in plastic containers and heat sealed with polyethylene / aluminum box composite material. Permission of oxygen isolation and moisture insulation.
The composition of the butter varies according to the manufacturer. But according to legal standards, the butter should not contain more than 16% soy water, 1% protein, 0.4% lactose, 0.15% milk ash, and different amounts of salt. Due to the high water content of butter, it is easy to lead to mold reproduction. The natural color of the butter depends on the carotene and fat bulb in the milk. The butter flavor is produced by the fermentation of the bacteria in the cream. Although fermented, it gives the butter a special aroma. To control the aromatic taste of butter and prevent improper fermentation and deterioration, starter cultures and fermentation microbial types should be used.
In the process of butter manufacturing, the milk is separated and the cream is stirred until the emulsion structure is destroyed, that is, the original emulsion in oil in water) is turned into an emulsion system of water in fat (water in oil). The variety and purity of milk and cream should be selected, which is an important factor affecting the quality of butter. The cream must be cooked (fermented) to complete the fragrance conversion process. But the hot cream affects the stirring, and the storage period is not as long as sweet creabbutter, because the fermented acid accelerates the catalysis of the metal and promotes the oxidation of fat.
Butter packaging requirements are mainly to protect its fragrance beads, tissue, appearance, moisture and color. Air-tight packaging is very important, not only to protect its fragrance from loss, but also to resist the pollution of external odor, because butter is easy to absorb external odor. Due to the emulsion characteristics of butter, the fat is particularly susceptible to oxidation and acolysis. The trace metal ions left on the processing plant also give the butter a "fishy" smell. Butter is usually wrapped in parchment, aluminum foil / sulfuric acid paper, or a composite material of aluminum foil and oil-proof paper. Parchment is crisp, should contain more than 9% water, coexist in no dust, humidity 50% to 80% clean place. If too dry, parchment will be brittle, easy to break when packaging. On the contrary, if it is too wet, it is easy to grow mold and pollute the butter. Although parchment is oil resistant, but still through oxygen, to its translucent light, easy to promote the oxidation of butter. The protective packaging for preservation is still the safest with aluminum foil composite material. However, the composite material of aluminum foil and plastic film is not ideal, because most of the plastic film has air permeability, resulting in the loss of butter fragrance, and the oil resistance is not good. Using aluminum foil / paper composite material, paper not only enhances, can reduce the thickness of aluminum foil, at the same time, paper can improve the process operation performance of packaging machine machinery. Aluminum foil / parchment composite packaging butter is widely used in European countries.
The packaging of the margarine:
Margarine packaging requires the following two protective functions:
① Protect the products in the process of transportation, storage and use from pollution, mainly to prevent microbial pollution, at the same time must have oxygen isolation, moisture-proof, oil resistance and maintain the fragrance of the product;
② Packaging should be attractive for sales, and convenient for consumers to use.
Small packages of margarine (and other oils such as lard) are usually made with parchment, grease proof paper or aluminum foil / parchment, aluminum foil / grease proof paper. Packaging materials must be beautifully printed performance design, so that it has a strong sales temptation. Box margarine is usually made of coated paper or aluminum foil composite material. Various plastic boxes such as polyvinyl chloride, polystyrene, acrylonitrile monobutadiene monostyrene copolymer are used in zui recently. The box making adopts the hot forming process, and its production efficiency and cost are more economical than those of injection molding. There are also coextruded plastic boxes and paper / plastic composite boxes to package margarine. Most of the lid are made of PVC plastic. The printed filling on the plastic lid shall include legal instructions, such as the composition of the product, product name and trademark, etc. If the requirements are more perfect, a layer of paper cover is wrapped on the outside of the plastic box as the outer layer, and the paper cover is also filled with the design to fully explain the product, promote the product, in order to expand sales.
Margarine is mainly used in pasta baking foods. The small package is used for family needs, from 10~15kg. A package is used for the pasta baking manufacturers and the unit canteen. Large packaging can be used in cans and boxes (metal cans and cartons), and the full design is simpler. It should be noted that if the margarine is exposed to air, it will oxidize to deterioration in only a few days at 40℃ to 50℃ temperatures.