Views: 0 Author: Site Editor Publish Time: 2022-09-21 Origin: Site
Due to the problem of the fresh-keeping period, many real specialty food stores cannot go out of the house and cannot be sold overnight. The market radius is very narrow, thus losing a huge consumer group. The modified atmosphere fresh-keeping packaging machine of Mingwei Packaging Machinery Co., Ltd. It solves the problem of food preservation, which can extend the preservation period of cooked food from 1 day to more than 7 days, which greatly expands the market radius of manufacturers, and also enables consumers to taste local specialties thousands of miles away at their doorsteps. Especially for cooked food manufacturers, it is undoubtedly a good news. A qualified packaging machine has two key technical indicators that must meet the corresponding requirements. These two indicators are: first, the gas replacement rate is high, and the second is the gas The mixed precision error rate is low. Whether the quality of packaging equipment is qualified or not, it is necessary to use these two key indicators to judge. As for the key performance of modified atmosphere packaging machine technology, we continue to look down.
Modified atmosphere preservation gas is generally composed of carbon dioxide (CO2), nitrogen (N2), oxygen (O2) and a small amount of special gases. Carbon dioxide can inhibit the growth and reproduction of most spoilage bacteria and molds, slow down the metabolism of fresh fruits and vegetables, and is the main antibacterial component in the fresh-keeping gas; oxygen can inhibit the growth of most anaerobic bacteria, maintain the color of fresh meat and maintain the needs of fresh fruits and vegetables. Oxygen respiration and keeping freshness; nitrogen is an inert gas, which does not work with food. As a filling gas, it forms a composite fresh-keeping gas with carbon dioxide, oxygen and special gases. Different foods, fruits and vegetables require different components and proportions of fresh-keeping gas.
The use of composite modified atmosphere packaging machine equipment for fresh-keeping packaging of food, fruit and vegetables requires a reasonable requirement for gas mixing accuracy error and gas replacement rate. In the standard of advanced packaging equipment in developed areas, the gas replacement rate is required to be more than 98%, and the error rate of the mixing accuracy of fresh-keeping gas is less than 2%. This is because the above two indicators play a crucial role in the preservation of food, fruits and vegetables. An example is as follows:
Example 1: When litchi is packaged in modified atmosphere fresh-keeping, the mixing ratio of the fresh-keeping gas is: oxygen (O2) concentration ratio of 4% to 6%; carbon dioxide (CO2) concentration ratio of 3% to 5%, damage concentration of 8%; the rest is filling gas Nitrogen gas (N2); if the O2 concentration is low, anaerobic respiration will occur, resulting in lychee fruit fermentation and tissue necrosis; high O2 concentration or low CO2 concentration will inhibit the decline of lychee metabolism and shorten the preservation period; high CO2 concentration ( >8%), it will cause damage to the peel and fruit and accelerate the deterioration of lychees.
Example 2: When packaging stewed vegetables (cooked food) with modified atmosphere fresh-keeping, the mixing ratio of the fresh-keeping gas is: nitrogen (N2) 64%-66%, carbon dioxide (CO2) 34%-36%, and the gas replacement rate is ≥98%. Since many microorganisms (bacteria) require O2 for their growth and reproduction, reducing oxygen levels can slow down the reproduction of bacteria (except for anaerobic bacteria). Experiments show that a reasonable mixture of N2 and CO2 forms a protective layer on the food surface with broad-spectrum antibacterial, color and taste preservation, and in a low-oxygen environment, the sauerkraut can be kept fresh. Therefore, when the error rate of gas mixing accuracy and the replacement rate cannot reach the index, its antibacterial and fresh-keeping effect is basically ineffective.
There are a lot of domestic food packaging technical materials, but the technology is backward, and it focuses on theory, and its practicability is not strong. In order for my country's food packaging industry to integrate into the new trend of international food packaging, take the initiative in the fierce market competition, and make the gap between my country's food packaging industry and developed regions continue to shorten, it is necessary to introduce and absorb foreign food packaging new technologies. Therefore, it is of great significance to increase the development, research and application of new food packaging technologies in my country. In order to meet the needs of modern society, the introduction of foreign advanced modified atmosphere packaging technology is an important condition for improving the level of modified atmosphere packaging technology in my country and maintaining, improving and extending the nutritional value of food.