Why is it difficult to keep fresh fruits and vegetables?
Fresh fruits and vegetables are still living organisms after harvesting, carrying out metabolic activities dominated by respiration. Because of the separation from the mother body, the supply of substances and energy is interrupted, and only by consuming its own carbohydrates, pectin, vitamins, organic acids and other substances to maintain life, resulting in a decline in the quality of fruits and vegetables.
In addition, the quality of fresh fruits and vegetables declined due to the following factors:
- Temperature and Humidity
- The Self-Characteristics of Fruits and Vegetables
- Gas environment
Preservation methods of fruits and vegetables commonly used at present:
The core problem of keeping fresh fruits and vegetables is how to slow down breathing, inhibit metabolism, and make them dormant or semi-dormant. More and more vegetables and fruits processors and storage owners are using modified atmosphere packaging. Following are commonly used fruit and vegetable preservation methods in the industry:
Preservation methods of fruits and vegetables are commonly used at present, which can make fruits and vegetables enter a certain dormancy state through low temperature, and the reproduction of microorganisms and the activity of enzymes can be inhibited to a certain extent. But because fruits and vegetables are still in normal atmospheric environment, the dormancy state is relatively shallow, so the preservation time is relatively short.
- Controlled Atmosphere Storage and Refrigeration
Compared with single refrigeration method, this method has certain advantages. The modified atmosphere storage is one of the most advanced fresh-keeping facilities for fruits and vegetables in the world. It can not only control the temperature and humidity in the warehouse, but also control the content of oxygen, carbon dioxide, ethylene and other gases in the warehouse. It can inhibit the physiological activity of fruits and vegetables by controlling the gas composition in the storage environment, and make the fruits and vegetables in the warehouse dormant. Practical application has proved that the use of controlled atmosphere fresh-keeping storehouse to store fresh fruits and vegetables has achieved good results both in terms of storage period and quality of fresh-keeping fruits and vegetables. However, the investment of controlled atmosphere storage plus refrigeration is relatively large, and the variety of single storage is single. The loss of controlled atmosphere environment makes fruits and vegetables enter the respiratory peak rapidly and the fresh-keeping period is too short. So its application has not been popularized.
- Air-conditioned Refrigerator Vehicle (Air-conditioned Container)
Compared with ordinary refrigeration trucks, air-conditioned refrigeration trucks have the advantages of high cost, high energy consumption and low actual transport capacity. In addition, air-conditioned refrigeration trucks and air-conditioned containers can only maintain the air-conditioned state during transportation, and fresh agricultural products are consumed too much in the sales links such as shelves. So the popularity is not very high.
- Modified Atmosphere Packaging
Shandong Kangbeite Food Packaging Machinery Co., Ltd. develops the series of modified atmosphere packaging technology and equipment, which is one of the most advanced fresh-keeping technologies of fruits and vegetables in the world. It not only retains the advantages of the modified atmosphere storage, but also overcomes the shortcomings of the modified atmosphere storage. Modified atmosphere state can be maintained in the storage, circulation, shelf of fresh agricultural products and even in family refrigerators, so that the nutrition, color, taste of fresh agricultural products are well preserved.
Its characteristics are small investment, good fresh-keeping effect, can achieve the complete combination of air-conditioned chain and refrigeration chain, so that fresh agricultural products get a better shelf life.
Working principle of modified atmosphere packaging for vegetables and fruits:
- What is the Modified Atmosphere packaging? The principle of modified atmosphere packaging is to replace the air in the plastic bags or trays of fruits and vegetables with compound fresh-keeping gas, change the gas ratio in the plastic bags or trays, and form a micro-air-conditioned environment in the bags or trays, that is, to form a micro-air-conditioned storage, so as to slow down the freshness. The metabolism of fruits and vegetables can prolong the shelf life and freshness of fruits and vegetables.
- The air for modified atmosphere packaging is generally composed of carbon dioxide (CO2), nitrogen (N2), oxygen (O2) and a small amount of special gases. Low oxygen content can slow down the respiration and inhibit metabolism of fruits and vegetables; properly increasing the concentration of CO2 can further slow down the respiration of fruits and vegetables; N2 is inert gas as filling purpose without reaction to vegetables and fruits.
After years of researches, Shandong Kangbeite Food Packaging Machinery Co., Ltd. has found that for different foods, fruits and vegetables, the air ratio in modified atmosphere packaging is totally different. When using modified atmosphere packaging equipment to preserve food fruits and vegetables, there is a reasonable requirement for gas mixing accuracy error and gas replacement rate. In the standard of advanced modified atmosphere packaging equipment, the gas replacement rate is more than 99.5%, and the precision error rate of fresh-keeping gas mixing is less than 2.0%. These two indicators play an important role in the preservation of fruits and vegetables.
Shelf life of some fresh vegetables and fruits in modified atmosphere packaging at 0-4oC storage
|Shelf life (days)|
Shandong Kangbeite Food Packaging Machinery Co., Ltd. is a professional manufacturer of packaging machines, including thermoforming packaging machines, MAP modified atmosphere packaging machines, VSP vacuum skin packaging machines, Vacuum packaging machines.
KANGBEITE PACKAGING MACHINERY has introduced a full series of vegetables and fruits modified atmosphere packaging machine to worldwide market.
Semi-auto tray sealing machine for MAP modified atmosphere packaging
- Customizable mold for different shape and size of trays/ bowls;
- SUS304 stainless steel structure
- Single mold/ Dual molds available
- Speed: 3-4 cycles per minute
Automatic inline tray sealing machine
- Suitable for various types of trays/bowls
- SUS304 stainless steel structure
- Auto loading available
- Conveying belt for easy finished packs unloading
Thermoforming packaging machine for MAP packaging
- Fits both rigid tray and flexible packages
- Trays containers automatically formed
- Fully automatic packing solution
- SUS304 stainless steel structure