Ten ways to store and preserve fruits
Fruit is a fresh food that is perishable after harvest. In order to extend the preservation period, scientific researchers from various countries have invented a variety of new preservation techniques. Here are 10 new technologies for preservation. kind.
1. Fresh-keeping carton: This is a new type of carton developed by the Japan Food Distribution System Association in recent years. The researchers used a kind of "ristobal stone" (a type of silicate rock) as an additive to the pulp. Because this kind of stone powder has unique good adsorption effect on various gases, is cheap and does not require low-temperature and high-cost equipment, and especially has a long-term preservation effect, and the weight of the preserved fruits will not be reduced, so merchants love it. Using it, it is even more unique for long-distance storage and transportation.
2. Microwave preservation: This is a preservation method used by a Dutch company to sterilize fruits at low temperatures. It uses microwaves to heat it to 72℃ in a short time (120s), and then puts the processed food on the market under 0~4℃ environmental conditions. It can be stored for 42~45 days without deterioration and is very It is suitable for supplying "seasonal fruits" in the off-season and is very popular among people.
3. Edible fruit preservative: This is an edible fruit preservative developed by a British food association. It is a "translucent emulsion" formulated with sucrose, starch, fatty acids and polyester. It can be sprayed, painted, and dipped to cover watermelons, tomatoes, bell peppers, eggplants, cucumbers, apples, etc. The shelf life of bananas and other surfaces can be as long as more than 200 days. This is because this preservative forms a "sealing film" on the surface of fruits and vegetables, which completely prevents oxygen from entering the inside of fruits and vegetables, thereby prolonging the ripening process of fruits and enhancing the preservation effect.
4. New film preservation: This is a disposable hygroscopic preservation plastic packaging film developed in Japan. It is composed of two translucent nylon films with strong water permeability. There is natural paste and sugar syrup with high osmotic pressure between the membranes, which can slowly absorb the water seeping out from the surface of the fruit and meat to achieve the preservation effect.
5. Pressurized preservation: It is a method of making food using pressure, successfully developed by the Institute of Food Science and Technology of Kyoto University in Japan. Pressurized sterilization of fruits can extend the preservation time and improve the fresh taste, but acid cannot work under pressure, so it is best to preserve fruits in the most delicious state.
6. Ceramic fresh-keeping bag: This is a fruit fresh-keeping bag with far-infrared ray effect developed by a Japanese company. It mainly coats the inside of the bag with a very thin layer of ceramic material, so through the ceramic The released infrared rays can have a strong "vibration" movement with the water contained in the fruit, thereby promoting the preservation of the fruit.
7. Microbial preservation method: Ethylene can promote the aging and ripening of fruits, so in order to achieve the purpose of preservation of fruits, ethylene must be removed. After screening and research, scientists isolated a "NH-10 strain" that can produce an "ethylene remover NH-T" substance that removes ethylene, which can prevent browning, loosening, and grain loss during grape storage. It can prevent tomatoes and peppers from losing water, changing color and becoming soft, and has obvious preservation effect.
8. Decompression preservation method: It is an emerging fruit storage method, which has a good preservation effect, and has the advantages of convenient management, simple operation, and low cost. At present, some countries such as the United Kingdom, the United States, Germany, and France have developed low-pressure containers with standard specifications, which have been widely used in long-distance transportation of fruits.
9. Hydrocarbon mixture preservation method: This is a "natural edible preservative" developed by a British Sempei biotechnology company that can double the storage life of pears, grapes and other fruits. . It uses a complex hydrocarbon mixture. When used, it is dissolved in water to form a solution state, and then the fruits to be kept fresh are soaked in the solution, so that the surface of the fruit is evenly coated with a layer of liquid agent. This greatly reduces the amount of oxygen absorbed, causing almost all CO2 produced by the fruit to be discharged. Therefore, the effect of preservatives is exactly like applying "narcotics" to fruits to make them dormant.
10. Electronic technology preservation method: It uses negative oxygen ions and ozone generated by high-voltage negative electrostatic fields to achieve the purpose. Negative oxygen ions can inactivate the enzymes that metabolize fruits, thereby reducing the respiration intensity of fruits and weakening the survival of ethylene, the fruit ripening agent.
Ozone is a strong oxidant and a good disinfectant and bactericide. It can not only kill and eliminate microorganisms on fruits and their secreted toxins, but also inhibit and delay the hydrolysis of organic matter in fruits, thereby extending the storage period of fruits.