Foreign emphasis on the research of fresh-keeping packaging technology for agricultural and sideline products

Agricultural and sideline products are necessary for human survival. Research on fresh-keeping packaging technology for agricultural and sideline products has become a hot research project in many countries. New research results on the research of fresh-keeping packaging technology for agricultural and sideline products have emerged in an endless stream.

Grain preservation technology

Bulgarian agricultural experts have invented a simple and economical new method of storing grain. When the crop is harvested, the seeds are lightly dried, filled into a large pocket made of polyethylene material, and then sealed. The grain thus preserved will neither evaporate moisture nor mold, and it will be preserved until the second spring of the year. The nutrient content of the grain will not be reduced at all.

Rice fresh-keeping bags

A Japanese company introduced a strong sealing bag, which is made of a plastic called “Cikron” and has an excellent oxygen barrier effect. It is used to package new rice, and its freshness is particularly good. It can keep the color, smell and taste of rice unchanged for a long time, and the carbon dioxide produced in the bag has the function of preventing insects and mildew.

A new method for keeping fresh fruits and vegetables

A U.S. company has developed a new method that keeps cut fruits and vegetables fresh. Researchers used cheese and acetylated monoacylglycerols extracted from vegetable oils to create a special covering that would prevent the transparent, edible, thin film-like flake from sticking to the surface of cut fruits and vegetables. Dehydration prevents blackening of the fruit and prevents the intrusion of microorganisms.

Fruit and vegetable cling film

Japanese experts have developed a disposable plastic wrap for fruits and vegetables. It consists of two layers of semi-permeable nylon packaging machine 'target=_blank' and a transparent film with high osmotic pressure between the two layers. The use of this cling film to package fruits and vegetables, can slowly absorb the water seeping from the surface of fruits and vegetables, so as to achieve the purpose of preservation.

Edible fruit preservatives

A British company has made an edible fruit preservative. It is a translucent emulsion formulated with sucrose, starch, fatty acids and polyesters. It can be sprayed, brushed or impregnated to cover apples, citrus, The surface of fruits such as watermelons, bananas and tomatoes has a shelf life of over 200 days. Because this preservative forms a layer of sealing film on the surface of the fruit, it can prevent oxygen from entering the interior of the fruit, thus prolonging the ripening process of the fruit and serving as a preservation effect. This preservative can be eaten with fruit.

Fruit fresh packing box

A Japanese paper company produced a fresh fruit packaging box. It adds a layer of polyethylene film on the corrugated paper of the corrugated carton, and then coats it with a waterproof wax coating containing trace amounts of fruit disinfectant to prevent fruit moisture from evaporating and restraining the breath from reaching freshness. Packing fruit in this box keeps the fruit fresh within a month.

Electronic preservation machine

France made an electronic preservation machine. Put this machine in the fruit and vegetable storage room, so that the stored fruits and vegetables can be fresh and picked up within 75 days. The preservation machine utilizes the negative oxygen ions and ozone generated by the negative electrostatic field to achieve the purpose of preservation; the negative oxygen ions can purify the fruits and vegetables through metabolic processes, thereby reducing the respiration process of fruits and vegetables, and reducing the production of fruit ripening agent ethylene; Ozone is a kind of strong oxidant, it is also a good disinfectant and bactericide. It can kill and eliminate microorganisms and their toxic substances on fruits and vegetables, inhibit and delay the decomposition of organic matter, thereby prolonging the storage period of fruits and vegetables.

High temperature treatment preservation method

The United Kingdom invented a high temperature storage technology for bulbs. This technology uses high temperature to inhibit the germination of bulbous vegetables. The storage room temperature is controlled at 23 °C, and the relative humidity is maintained at 75%. In this way, long-term storage and preservation can be achieved. It is said that onions can be stored for 8 months under such conditions.

Decompression treatment method

Japan has developed a technology for the preservation of fruits and vegetables under reduced pressure. This preservation method is mainly used to reduce air pressure, with the low temperature and high temperature, and use low-pressure air circulation and other measures to create a favorable storage environment for fruits and vegetables. The low pressure of the storage chamber is generated by vacuum pumping the indoor air. The low pressure is controlled below 100 mmHg and the minimum is 8 mmHg. The relative humidity in the air is controlled by a humidifier installed in the room, which is generally more than 90%. This method reduces the amount of oxygen in the room during the evacuation process, keeps the respiration of fruits and vegetables at the lowest level, and also eliminates some of the indoor gases such as carbon dioxide and ethylene, which is beneficial to the long-term storage of fruits and vegetables.

Air transport of fruits and vegetables

In order to keep fruits and vegetables fresh during the airlift process, a U.S. company invented a new method to reduce oxygen and increase nitrogen content in packaging boxes to keep fruits and vegetables fresh. This method uses a new type of air conditioning box with air-conditioning performance. This package has a special film, which can absorb oxygen molecules and allow nitrogen to pass through. After entering the package through the film in the air, the content of nitrogen in the box can be as high as 98% or more, so that the respiration of fruits and vegetables can be slowed down and the purpose of keeping freshness for a longer period of time can be achieved.

New fruit and vegetable fresh-keeping bag

A U.S. company has launched a new type of plastic bags for fruit and vegetable preservation that can extend the shelf life of fruits and vegetables and reduce the loss of fruit and vegetables caused by excessive aging. This kind of packaging bag is made of natural activated clay and polyethylene. It is like a very fine filter screen. Gases and moisture produced during the ripening process of fruits and vegetables can pass through the packaging bag. Fungus is not easy to grow in the bag, so fruits and vegetables can be made. The freshness is more than doubled.

Live shrimp transport with new packaging

A food company in Hokkaido, Japan, has developed a special package for the delivery of live shrimp in order to solve the problem that it is difficult for citizens to eat live shrimp. The package uses polyethylene as the inner layer, foam styrene as the outer layer, and crushed ice between the double layers. The inner layer should prevent water leakage and the outer layer should prevent damage. In the polyethylene tank where the live shrimp is moved, the sterilized seawater is filled with a certain amount of oxygen, and then sealed with a lid and transported. With this method, the survival rate of live shrimp can be maintained at more than 90% within 24 hours even at an external temperature of up to 40°C. When the outside temperature is low, the survival rate of live shrimp will be higher.
(Shen Xueyou)

Source: National Times