New Technology and Materials for Food Preservation Packaging (2)

It is very stable under normal humidity and can also radiate external heat. Therefore, the use of trehalose to preserve foods is not only very satisfactory, but also requires no special equipment. The operation is very simple, as long as care is taken to avoid long-term storage in contact with water. Trehalose is present in yeast, and yeast can multiply, so trehalose is readily available. The use of trehalose to preserve foods can successfully solve problems such as the disappearance of color, changes in taste, dry and hard metamorphism of meat, and destruction of vitamins when fresh foods are frozen and dehydrated. At the same time, the degree of processing is also very simple. After removing impurities from various foods, it is sprinkled with trehalose, stirred or flipped several times to make the trehalose evenly filled with foods. That is, the foods can be put on the shelf for sale or stored in the food basket for a long time without Worry about deterioration. When food is consumed, the food is taken out and refreshed. The original color will be immediately restored and the taste will be as fresh as ever. The vitamins contained in meat remain intact, their color, aroma, taste, and nutrient content have not changed and are comparable to fresh foods. If this technology is further developed and perfected, it will surely be widely adopted and its prospects are very broad.

9. Decompression treatment preservation method. In recent years, a vacuum storage of fruit and vegetable preservation technology has been widely used abroad. The principle of this preservation method is not complicated. The main application is to reduce air pressure, cooperate with low pressure and high temperature, and use low-pressure air to circulate and other measures to create a favorable storage environment for fruits and vegetables. The low pressure in the storage room is generated by vacuum pumping the room air, and the low pressure is controlled below 13.3 kPa with a minimum of 0.106 kPa. The relative humidity in the air is controlled by a humidifier installed in the room, which is generally more than 90%. Since the exhaust gas reduces the oxygen content in the room, the respiration of fruits and vegetables is maintained at the lowest level, while also eliminating the indoor Part of the gas, such as carbon dioxide and ethylene, is conducive to the long-term storage of fruits and vegetables.

10. Mugwort antibacterial bag. U.S. uses Artemisia to produce a new type of food preservation bag that can be used repeatedly and eventually decomposed by microorganisms. Artemisia is a kind of wild plant that has antibacterial, anti-mildew, insect-proof and medicinal functions. According to the information provided by the company that produced the Artemisia storage bag, the newly developed food preservation bag is made of a film made by mixing 60% of degradable plastic, 20% of mugwort powder and 20% of additive. Put vegetables, fruits and other foods in this kind of fresh-keeping bag and put it in the refrigerator to ensure that the food is in an antibacterial, mold-proof and insect-proof environment, and can extend the food preservation period by two times. If the storage bag is dirty, it can be reused after brushing until it is broken. After being discarded, the bag can be broken down by microorganisms.

11. A new type of fruit preservative. The U.S. Agricultural Research Center has developed and developed a newest fruit preservative. This preservative is prepared by mixing the 4-ethyl resorcinol and calcium compounds extracted from natural plants in proportion, and it has the effect of inhibiting biological activity and enzyme oxidizing ability, and thus has a good preservation effect. Tests have shown that peeling fresh apples and spraying them with fresh-keeping agents can make apple slices not discolored even at temperatures around 20 degrees Celsius for several weeks, and they are also suitable for keeping fresh fruits such as peaches and bananas. In order to keep fruits and vegetables fresh in the air, a U.S. company invented a new method to reduce the oxygen content and increase the nitrogen content in the packaging box. This kind of new air-conditioned packaging box has a special The film, the film fiber can absorb oxygen molecules and allow nitrogen to pass through, so after the air enters the packaging box through the film, the nitrogen content in the box can be as high as 98% or more. High content of nitrogen can make the respiration of fruits and vegetables slow down. The purpose of keeping freshness for a long time. A food company in the United States made an edible package using cheese and acetylated monoglycerides extracted from vegetable oils. This is a transparent, odorless film that is affixed to the surface of cut fruits and vegetables to prevent dehydration and blackening of fruits and vegetables, and to prevent the intrusion of microorganisms, enabling the cutting of fruits and vegetables for a long time. Stay fresh.

12. Fresh flowers packaging. In response to the problem of flowers wilting, Israel recently developed a new method for fresh-keeping packaging of flowers. The method is to improve the bubble-filled plastic, which is generally used for packaging computers and electronic instruments, to make a new packaging filling, which is filled in a box filled with flowers, not only inside the box but also inside the box. The temperature is lowered by a few degrees, and the exchange of air inside and outside the box is also slowed down, which plays a good role in freshness preservation.

13. Testable toxic plastic wrap. Canadian Toxin Plastic Panels Co., Ltd. invented a food preservation film that can detect whether food is deteriorating or toxic. This plastic wrap, coated with a chemical, deforms (round to flat) when it encounters certain toxins.

It has been determined that this plastic wrap can detect Salmonella, Trichoderma, Escherichia, and Listeria. The coated chemicals are non-toxic and will not contaminate food and will not affect human health.

14. Negative oxygen ion food preservation machine. Japan's Chang News Electric Co., Ltd. developed a negative oxygen ion food preservation machine. This preservation machine uses the negative oxygen ions and ozone produced by high-voltage negative electrostatic fields to achieve the purpose of preservation. Negative oxygen ions can effectively inhibit the enzyme activity in the metabolism of fruits and vegetables and reduce the production of ethylene with ripening effect in fruits and vegetables. At the same time, ozone can not only effectively sterilize and inhibit the decomposition of organic matter, but also extend the fruits and vegetables. The storage period.

15. Irradiation and fresh-keeping packaging. Is the use of nuclear technology produced by ionizing radiation irradiation of food packaging, can effectively inhibit or eliminate food bacteria, fungi and many microorganisms, so that food to maintain the original quality, flavor and nutritional value. Sealed fruits and vegetables, fish, after irradiation with a prescribed dose of radiation, due to killing the microbial community and inhibiting the maturation process, the storage period at room temperature is significantly prolonged. For example, tomatoes irradiated with gamma rays at a dose of 4000 Gy can be stored for 30 days at 8 degrees Celsius. In a low vacuum (5.30 kPa to 8.0 kPa), packaged in polymer bags and irradiated with gamma radiation at doses of 4,000 Gy and 6,000 Gy to semi-finished beef or pork products at temperatures between 3 degrees Celsius and 5 degrees Celsius. Save 40 days and 60 days respectively. Compared with heat sterilization and cold storage, radiation packaging has the characteristics of food can be kept intact for a long time, there is no chemical carcinogen residue; can use new packaging, and direct irradiation of the packaged food; can be automated production and other advantages. Studies have shown that as long as the irradiation dose does not exceed 10,000 Gy, there is no adverse effect on any food and human health can be guaranteed. China has established a scientific and safe irradiation center, and the irradiation technology has reached the world's advanced level. It is believed that in the future, China's irradiation and fresh-keeping packaging will receive new and greater development.

16. Modified atmosphere packaging: In the European market, a modified atmosphere packaging bag for fruit and vegetable food packaging has emerged in recent years. This high-oxygen spontaneous atmosphere packaging bag, the combination ratio of oxygen, carbon dioxide and nitrogen in the bag can be adjusted according to the physiological characteristics of different fruits and vegetables, such as 80% to 90% oxygen and 10% to 20% for perishable fruits and vegetables. %carbon dioxide. This kind of package has the advantages of inhibition of enzyme activity, prevention of browning of fruits and vegetables, prevention of fermentation caused by anaerobic respiration, maintenance of the quality of fruits and vegetables, effective inhibition of aerobic and anaerobic microbial growth, and prevention of decay. Fresh mushrooms are packaged in high-oxygen tones and the shelf life can reach 8 days at 8 degrees Celsius.

17. Long-lasting antibacterial antibacterial paper. The mildew-proof wrapping paper, which is generally used for packaging of foods, fruits and vegetables, etc., is a kind of agent for preventing the growth of the mold caused by the growth of paper during its manufacture. It can prevent the deterioration and deterioration of substances caused by moldy organisms, and it is packaged together with the articles at room temperature. , It can form an antibacterial atmosphere around the object, which can destroy the existence of molds harmful to human health without affecting human health, non-toxic, odorless, non-corrosive, so as to achieve the purpose of anti-mildew, is the use of chemical antibacterial agents in recent years A new breakthrough. The long-term anti-mildew paper produced by a company in Japan is a new type of packaging paper that can prevent food moldy and spoilage for a long time and does not damage the flavor of food. The paper is an aqueous solution in which a special monoglyceride is fused with a compound therein, dissolved as an effective component in water and ethanol, and then sprayed or infiltrated on paper and finally heated and dried. It can be used to package a variety of foods. In addition, a Japanese company has produced a new kind of mildew-proof and antibacterial wrapping paper that can prevent food moldy and spoilage for a long time and does not harm food flavor. The paper is an aqueous solution of a mixture of a special monoglyceride and a compound thereof dissolved in water and ethanol as an active ingredient, which is then sprayed or infiltrated on paper and finally dried by heating. It can be used to package a variety of foods. The company also manufactures a kind of anti-corrosion paper that can be used for food packaging. The preparation method is: first, the raw paper is immersed in an ethanol solution containing 20% ​​of succinic acid, 33% of sodium succinate and 0.07% of sorbic acid, and then dried. Foods with marinade in this type of paper can be preserved at 38 degrees Celsius for 3 weeks without deterioration.

18. Fruit lap paper. This is a fresh-keeping paper developed and produced in Singapore. The paper contains antibacterial and bactericidal agents. It is used to package apples and opened after six months. The fruit is still full and the background is green and green, just like it was just picked. There is also a kind of fruit fresh-keeping paper that can keep fresh citrus for 3 months, and litchi can also keep fresh for more than 30 days. In addition, Japan's Showa Chemical Co., Ltd. developed a fruit lap wrap that uses a certain kind of mineral concentrate containing phosphoric acid as a raw material to infiltrate absorbent paper bags. Use this kind of paper container to pack vegetables and fruits. During transportation, vegetables and fruits can be supplied with nutrients from mineral concentrates. Practice has proved that calcium phosphate can absorb ethylene and carbon dioxide gas, inhibit the decomposition of chlorophyll, play a preservation effect.

19. Corrosion preservation packaging paper. Orenson Paper Co., Ltd. of Sweden introduced highly breathable food packaging paper. Its inner and outer layers have a thin layer of fluororesin, no water, no oil, wrapped foods can make the same temperature inside and outside, put the refrigerator can better maintain the original flavor of food, fresh as ever. A Japanese company uses a method in which paper is first immersed in an ethanol solution containing 2% succinic acid, 33% sodium succinate and 0.07% sorbic acid, and then dried to make paper for food packaging. The food used for packaging can be stored at 38 degrees Celsius. 3 weeks without deterioration.

20. Porcelain fresh wrapping paper. Combines inflatable packaging technology with advanced ceramic paper packaging technology. The vegetables are packed in thin-film bags with porcelain paper, and the air in the bags is removed by vacuum, and then the inert gas is filled. After the bags are sealed, the porcelain paper continuously emits harmless long-wave infrared radiation. Thus limiting the movement of bacteria in the water molecules, but also can absorb a small amount of ethylene gas, greatly prolong the preservation time of vegetables.

21. Smart plastic preservation. In food packaging, recently developed intelligent fresh plastic films made of truly efficient materials, which not only prevent pollution, but also have good functions such as preventing the sun from irradiating light and preventing oxidation. Such smart packaging can even be used in The warning signal is issued when the package is damaged or the storage temperature is too high. This new cling film developed by the Fraunhofer Processing Technology and Packaging Research Institute is currently undergoing special laboratory tests. Here, researchers studied the so-called oxygen scavenger effect. The main focus is on a scavenger/indicator system that not only captures oxygen but also emits a signal that the oxygen content of the package is too high by discoloration. For example, if the product rots or the packaging is damaged, a dazzling package of spots appears on the package, and the new signal substance works similarly. The substance activates when the storage temperature rises, telling people that the product was once overheated during transit. Oxygen scavenger research involves different molecules, such as iron compounds into polymers. The advantage of this cling film is that it can reduce the use of additives (such as antioxidants) in foods. These scavengers have been able to prevent the oxidation of orange juice in glass or plastic bottles. It is estimated that the cling film can be used to package other foods in the next few years. . In addition, LANXESS, of Leverkulen, has also issued a smart cling film using nano fillers that also prevents oxidation of the product. This is a blend of thin silicate sheets that are only 1 nanometer thick at the time of manufacture. Polyamide. They are like a wall of a maze, so that the path of oxygen molecules through the cling film is greatly extended. When the air