Talking about high voltage electrostatic preservation technology of fruits and vegetables

With the development of electromagnetism and biology, research on the use of electric fields to regulate the life activities of living organisms has become more and more extensive. In the aspect of fresh-keeping after fruit and vegetable picking, high-pressure electrostatic technology can improve the appearance indexes such as hardness and color of fruits and vegetables during storage, delay the peak of breathing, increase the related enzyme activity in the body, and prolong the storage period. Therefore, the use of high-voltage electrostatic technology in the preservation of fruits and vegetables has gradually attracted the attention of researchers. Moreover, the use of high-voltage electrostatic preservative technology has obvious effects, low energy consumption, flexible operation, and no secondary pollution, and has almost no effect on the quality of fruits and vegetables. This new technology for the preservation of fruits and vegetables has great research and development value both in terms of energy saving and in terms of fruit and vegetable preservation quality.

Principle of high voltage electrostatic preservation technology

The high-pressure electrostatic technology began to study the physiological aspects of fruit and vegetable harvesting at the end of the 20th century. It was found that the high-voltage electrostatic treatment of fruits and vegetables during storage and the post-mortem physiological indicators were improved. Moreover, by adjusting the electric field strength, the metabolism-related enzymes in the body can be affected, thereby prolonging the storage period of fruits and vegetables. At present, domestic and foreign scholars' research on high-voltage electrostatic preservation mainly focuses on applied research, and the research progress on its mechanism of action is slow. Some scholars put forward the conjecture on the principle of high-voltage electrostatic preservation based on electromagnetic principle and experimental research.

â—†Change cell membrane potential

The applied electric field affects the physiological metabolism of the body by changing the transmembrane potential of the biological cell membrane. The membrane potential difference of the biological cell membrane is about 107V/m. This potential difference is unevenly distributed on the cell surface. In some cases, such as changes in the external environment or external environment stimulation, the field strength peak appears on the surface of the cell. Strong peaks can affect the structure and function of the membrane system. Secondly, the change of membrane potential difference is accompanied by the directional movement of charged ions on both sides of the membrane, thereby generating bio-current, biochemical reaction, inhibition of ATP production, and delaying cell metabolism. At the same time, the cell membrane has selective absorption, can absorb the necessary nutrients, and discharge metabolic waste. Appropriate electric field intensity treatment will affect the carrier protein embedded on the cell membrane, change the selectivity of the membrane, delay the physiological metabolism of fruits and vegetables after harvest, and maintain the storage quality of fruits and vegetables.

â—†Change the internal bioelectric field of the body

The applied electric field interferes with the electrical transmission of the respiratory system by affecting the bioelectric field inside the body. According to this view, the fruit is often positively charged after the fruit picking, and the fruit core is negatively charged. After the applied electric field treatment, the fruit tissue is polarized by the applied electric field, which generates polarized charges and changes the electrical properties inside and outside the fruit. Increased, thus affecting the internal redox reaction of the fruit, which has a certain effect on the storage and preservation of fruits and vegetables after harvest. Moreover, some researchers believe that since the redox reaction in the living body mainly uses iron as an electron transport intermediate, the redox state of iron changes due to the change of the tissue potential difference, which affects the normal electron transfer of the postharvest body. Affect the metabolism of fruits and vegetables after harvest. Secondly, the polarization of the electric field inside the fruit and vegetable will also affect the activity of free radicals and the state of metal ions in the active center of some enzyme proteins, thus affecting the activity of free radicals involved in oxidation and the activity of enzymes in metabolic reactions, thereby affecting the storage of fruits and vegetables after harvest. With preservation quality.

â—†Change the state of moisture in the living body

The activity of enzymes in fruits and vegetables affects the physiological response of the body. The moisture around the enzyme protein is not only a condition for the survival of fruits and vegetables, but also an important component of fruit and vegetable cells. The applied electric field causes a change in the state of the water. It is believed that the applied electric field causes the water to resonate, causing the structure of the water and the binding state of the water and the enzyme to change, thereby inactivating the enzyme. This view can explain the reduced activity of the polygalacturonase and carboxymethylcellulase of the fruit treated by the high voltage electrostatic field and inhibit the softening of fruits and vegetables during storage.

â—†Other

When a high-voltage electrostatic field acts on fruits and vegetables, the air in the field will ionize, generating ion fog and a certain amount of ozone. The negative ions have the effects of inhibiting the metabolism of fruits and vegetables, reducing the respiratory intensity and reducing the enzyme activity. Ozone is a strong oxidant, which can sterilize, heal the wounds of fruits and vegetables, and improve the ability of fruits and vegetables to resist microorganisms, thus reducing the decay of fruits and vegetables. At the same time, ozone can react with ethylene, ethanol and acetaldehyde, and indirectly protects fruits and vegetables. The study found that during the high-voltage electrostatic field treatment, the amount of ozone produced was small, and the effect of high-temperature electrostatic treatment was not significantly changed after ozone was excluded, indicating that the effect of ozone is not a major factor.
It is also believed that since the life activities of organisms are realized by successive expression of related genes, high-voltage electrostatic fields may also be realized by regulating the expression of related genes in cells.

At present, the principle of high-voltage electrostatic preservation technology requires a lot of scientific research to prove. And there are differences in the preservation mechanism of different fruits and vegetables. The preservation effect of each fruit and vegetable may be caused by one or more electrostatic effects. This requires further scientific research to determine for better application to production practices.

Application of high voltage electrostatic technology

From the beginning of the study of electromagnetic biology in the 19th century to the introduction of high-voltage electrostatic preservation technology at the end of the 20th century, high-voltage electrostatic technology has achieved some results in agricultural production and processing, which can be applied to fruit and vegetable preservation, food sterilization, drying, freezing and thawing. And food reminders. In the aspect of fresh-keeping of fruits and vegetables, high-voltage static technology can prolong the shelf life of fruits and vegetables, reduce the decay rate of fruits and vegetables, inhibit respiration, reduce ethylene release, slow down the reduction of fruit and vegetable hardness, soluble solids, Vc, etc. during storage, and interfere with the metabolism of reactive oxygen species. Etc., in order to achieve the purpose of preservation of fruits and vegetables.

â—† equipment

The equipment for high-voltage electrostatic preservation mainly consists of experimental cold storage, high-voltage electrostatic preservative test bench, electric field generating device and auxiliary device. Among them, the experimental cold storage can adjust the temperature and humidity of the storage environment. The high-voltage electrostatic preservative test bench consists of stainless steel plates, which can adjust the electric field strength by adjusting the plate spacing. The electric field generating device includes a high voltage power source, a discharge grounding body, a high voltage wire, an insulating sleeve, and the like. Among them, the high-voltage power supply is usually a high-voltage transformer with a voltage of 0-60kV and a current of 0-2.5mA, and outputs a negative high voltage. In addition, high-voltage electrostatic preservative equipment also has auxiliary devices such as controllers, sensors, safety valves, and wet temperature control.

The process of preserving fruits and vegetables by high-voltage electrostatic field is: putting the whole device into the cold storage, the fruits and vegetables are placed on the parallel plate of the fresh-keeping experimental platform in an orderly manner, the power is turned on, and two parallel electrode plates are used to generate a high-voltage electrostatic field, which is passed through a transformer. The pressure produces a high DC voltage to treat the fruits and vegetables between the plates.

â—†Application

As a new type of fresh-keeping technology for fruits and vegetables, high-voltage electrostatic preservative technology has attracted the attention of researchers with its good preservation effect. From the experimental results, high-voltage electrostatic technology has a good preservation effect on the storage appearance and physiological activity of fruits and vegetables.

1) Impact on the appearance of fruits and vegetables

The storage period of fruits and vegetables treated by high voltage static electricity is prolonged, the rate of decay is reduced, the surface stain is reduced, the browning of pulp is reduced, and the water loss is reduced. The pears treated with the high-voltage electrostatic field did not undergo fruit browning, while the untreated group had a browning rate of 25% after 240 days of storage. The blueberry treated by the high-voltage electrostatic field has a fruit decay rate of 50% after storage for a certain period of time, while the fruit decay rate of the non-electric field treatment reaches 90%.

2) Influence on the hardness of fruits and vegetables

Fruit hardness is an important sensory quality evaluation index for measuring fruit quality. Studies have shown that the hardness of fruits and vegetables treated by high-voltage electrostatic field during storage period is significantly higher than that of the control group. The apple hardness value of the treatment group decreased slowly after 15 days than the control group. After 12 days of storage, the hardness of the high-voltage electrostatically treated fruit was higher than that of the control group.

3) Effect on cell membrane permeability

The cell membrane of fruit and vegetable cells has selective permeability, and various adverse damage or aging can cause changes or loss of cell membrane permeability. The high-voltage electrostatic field has a certain repairing effect on the cell membrane, which can reduce the electrical conductivity of the tissue exudate. After the citrus was harvested and treated by high-voltage electrostatic field, the pericarp cell permeability was lower than that of the control group.

4) Effect on the respiratory intensity of fruits and vegetables

Fruits and vegetables still carry out a certain degree of physiological activities after harvesting to further ripen and improve their own immunity. However, too vigorous breathing will rapidly break down nutrients, accelerate the decay of fruits and vegetables, and shorten the storage period of fruits and vegetables. Therefore, controlling the intensity of breathing during storage is critical. The high-voltage electrostatically treated fruits and vegetables have lower respiratory intensity than the untreated group, and the red-golden apples are climacteric fruits. If treated with a high-voltage electrostatic field of 100kV/m per day, the apples are stored for 20 days to 35 days. The breathing intensity was significantly lower than that of the control group. The respiratory peak appeared on the 30th day after harvest, and the respiratory intensity was reduced by 15.3% compared with the control.

5) Effect on ethylene release

During the growth and metabolism of fruits and vegetables, endogenous ethylene will be released to promote its own maturation. Therefore, during the storage of fruits and vegetables, the release of ethylene should be minimized, and the ripening of fruits and vegetables should be delayed. High-voltage electrostatic treatment can reduce the release of ethylene to some extent. The high-voltage electrostatically treated green peppers released less ethylene than the control group. After the high-voltage electrostatic field treatment of pears, the peak of ethylene release was delayed by 60 days, and the peak of the treatment group was less than 1/2 of the control group.

6) Effect on the content of Vc, soluble sugar, anthocyanin and chlorophyll

During the storage period, fruits and vegetables are still carrying out life activities, and various substances in the body are continuously decomposed, affecting the storage quality and nutritional value of fruits and vegetables. Therefore, measuring the change of various substances during storage is also an indicator for evaluating the quality of storage. High-voltage electrostatic treatment made the content of certain nutrients higher than that of the control group. The Vc content of apple decreased with the storage time during storage. The Vc content of the electric field treatment group was significantly higher than that of the control group after 40 days. The nutrient content of citrus fruits treated by high-voltage electrostatic field was higher than that of the control group. For example, 110 days after harvest, the total sugar content was 14.2% higher than that of the control group, the reducing sugar was 42.6% higher, the organic acid was 7.7% higher, and the Vc was higher. L0%. It indicated that the citrus fruit was transformed and consumed slowly after being treated by high voltage electrostatic field. Conducive to storage.

7) Effects on enzyme activities related to fruit and vegetable during storage

All metabolic activities in the organism are carried out under the catalysis of many enzymes. After harvesting, fruits and vegetables still undergo a series of physiological and biochemical changes such as continued ripening until final aging and death. Among them, there are many kinds of enzymes involved in these changes. Some researchers believe that the post-harvest aging process of fruits and vegetables is actually the process of dysregulation and accumulation of active oxygen metabolism. The reason why the high-voltage electrostatic field can prolong the preservation period of fruits and vegetables may be due to the removal of reactive oxygen species under the action of a certain intensity of electric field. The related enzyme activity is increased. Peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) in vivo have been improved to some extent after high-voltage electrostatic field treatment, and their aging products are also significantly reduced. Polyphenol oxidase (PPO) in plants can convert phenolic substances in tissues into strontium and its polymerization products, which not only affects the appearance of the fruit, but also reduces the nutrient content. The strawberry fruit is treated by high-voltage electrostatic field. Phenol oxidase (PPO) activity was lower than that of the control group. Malondialdehyde is a tissue membrane lipid peroxidation product, and its content directly reflects the tissue aging level. The malondialdehyde content of strawberry fruit treated by high electrostatic field is lower than that of the control group.

8) Impact on chilling damage

Fruits and vegetables are susceptible to physiological diseases after being chilled, reducing their disease resistance, and high-voltage electrostatic fields have the effect of inhibiting chilling damage of fruits and vegetables.

High-voltage electrostatic field treatment can reduce the chilling injury index, rust spot index, membrane permeability and membrane lipid peroxidation of kidney beans stored at 5 °C, and inhibit chilling damage. For green peppers and eggplants stored at 2 °C, there is also a certain inhibition of chilling effects.

High-voltage electrostatic preservative technology is a new type of preservation technology with good application effect and economical energy saving. At present, the application of high-voltage static electricity in the preservation of fruits and vegetables is mainly concentrated in scientific research. Representative research includes the study of high-pressure static electricity on post-harvest preservation of tomatoes, the effect on the freshness of green peppers, and the effect on apple preservation.

Outlook

At present, research on high-voltage electrostatic preservative technology for fruits and vegetables has just started, and the physical, chemical and biological effects and application optimization of it are still in the exploration stage. However, as a new type of fresh-keeping technology, high-voltage electrostatic preservative technology for fruits and vegetables has great space and broad development prospects in scientific research and production practice. It is a hot technology in the preservation of fruits and vegetables today. With the deepening of research, the understanding of the doubts and difficulties of this technology will be more thorough, so that we can better regulate various factors in the application process, achieve the purpose of efficient preservation of fruits and vegetables and prolong storage period.

Best class: Organic Goji Berry ,Size: 220 grains/50g

What Do You Know About The Effects Of Organic Fertilizer?

Biological organic fertilizer refers to the active microorganisms compounded by specific microorganisms and organic materials from animal and plant residues after the harmless treatment and decomposition, it also contains nitrogen, phosphorus and potassium fertilizers with rich organic matters. It has many advantages of no pollution and durable effects, it is also helpful in strengthening seedlings, ameliorating soil, increasing yields and improving qualities. Meanwhile, using organic fertilizer can avoid environmental pollution, ecological destruction, fertility decline and other drawbacks caused by chemical fertilizers and pesticides.

The specific functional microorganism of biological organic fertilizer

➤ To cultivate a large number of azotobacter by using carbon source and nitrogen from the organic matters in soil and the nitrogen dioxide in the air.

➤ To decompose phosphate-solubilizing bacteria and potassium bacteria with P and K in the soil or the soil parent material.

➤ To inhibit pathogen growth and promote the reproduction of bacteria.

 

Generally, the bio organic fertilizer has quantitative microbes per gram, after applied into soil, under the condition of 25~35℃ of ground temperature, pH 5.5 – 8.5, 50 ~ 70% of water in the soil, no fungicide residues, the azotobacter, phosphate-solubilizing bacteria, potassium bacteria and bacteria can breed a generation every 20 minutes with growing exponentially. Each beneficial bacteria is a storehouse of fertilizer, the production factory of beneficial bacteria is moved under ground and produces nitrogen, phosphorus, potassium and other trace elements for plants to absorb, thus increasing the yield and quality, improving the quality of soil, promoting cultivating and reducing the occurrence of pests and diseases.

EU organic food certification:

Category	SO2	Pesticide
Organic goji berry	<10ppm	No pesticide (with organic certificate)

· USDA organic Certificate No.: A2015–00494/2016-07387 Authority :Kiwa BCS 

· EU organic Certificate No.: A2015-00494/2016-07386 code:CN-BIO-141 Authority :Kiwa BCS

Size 220 Organic Goji Berry

Size 220 Organic Goji Berry,Ningxia Organic Goji Berry,Small Size Organic Goji Berry,Bulk Organic Goji Berries

NINGXIA UNION-SURE CO., LTD. , http://www.unionsuregoji.com