Modern food packaging is multifunctional. Its main purpose is to create an aesthetic appearance in order to attract the attention of potential buyers. But there are other reasons to pay attention to packaging, for example, giving products such properties as ease of transportation and increased shelf life. The latter quality is especially important, since unsold goods are subject to destruction, which entails direct losses.
Vacuum packaging of fish is one of the most popular methods for solving all these problems. It does not require significant investments and large production facilities, therefore it is available even for small enterprises.
Depending on the volume of production, either high-performance lines or semi-automatic machines are used, which have become the most massive device with which the fish is packaged.
Various vacuum packaging semiautomatic devices are manufactured: single, double chamber, floor (on wheels) and table. The sizes and shapes of the cameras are also different. Packaging of fish is usually done in machines with an oblong chamber made of stainless steel, since aluminum does not tolerate the acidic environment characteristic of this type of product.
The principle of construction of any vacuum packer is quite simple, in its design there is always a compressor that draws air from the chamber, and a welder that creates a seam on a polymer bag. In addition, a control and monitoring scheme is required during operation of the system, including a pressure gauge.
The product, in this case, fish, is placed in vacuum bags, which should be considered. They are made of a barrier polymer film having a multilayer structure. The requirements for the packages are quite serious: they must have optical properties that allow you to visually assess the quality of the product, the specified thickness measured in microns (for example, 60, 100, 120 or 150), and the sizes needed by the customer, and they can be non-standard. In addition, one of the sides is opaque in order to make the fish look more beautiful. Colors are chosen based on what type of product is packaged, for example, red varieties look great against a golden background. Packaging for fish is usually oblong, while for meat products square bags are more often used.
The welders inside the chamber may also differ, they are linear and angular. The latter are used for closing on both sides in cases where the fish is long and it is difficult to put it in a bag through its narrow side.
Vacuum packaging of fish can significantly extend the shelf life if it is preliminarily displaced from the chamber by special gas mixtures prepared for each product. The fact is that in nature there are anaerobic bacteria, which lack of air does not interfere with multiplying and harming packaged fish. The so-called "pre-gas", which precedes the normal packer cycle, reliably protects against them.
The operation of vacuum packers is quite simple and does not require special qualifications. You should monitor the condition of the Teflon fabric with which the heating elements of the welders are covered, and monitor the condition of the oil in the compressor through a special glass window. If its color becomes beige, foam is visible, then it needs to be changed.