To antagonize microorganisms to deal with the safety of the raw bacteria and fruit and vegetable health

Fruit and vegetables play a vital role in promoting human nutritional balance. With the improvement of the living standards of the people in my country and the popularization of nutritional knowledge, the consumption of fruits and vegetables has increased significantly. During the storage and transportation stage of fruits and vegetables, it was susceptible to diseases caused by pathogenic bacteria, causing rotten deterioration. Traditionally, the use of chemical sterilizers to prevent the disease after the use of fruits and vegetables, but the residue of the bactericide easily causes harm to consumers' health. In order to ensure the safety of fruits and vegetables, the use of antagonistic microorganisms to perform biological control on fruit and vegetable diseases in the study became a hot spot for research.

Zhang Hongyin, an expert in China Food Think Tank and Deputy Dean of the School of Food and Biological Engineering of Jiangsu University, said that at present, my country has made great progress in the screening of antagonistic microorganisms, the mechanism of biological prevention, improvement of biological prevention and control, and antagonistic microbial agentization. The commercialization of biological prevention and treatment after the harvesting of fruits and vegetables is of great significance to help the rapid and healthy development of my country's fruit and vegetable industry and rural revitalization.

Zhang Hongyin, deputy dean of the School of Food and Biological Engineering, Jiangsu University (first from the right)

After the harvest of fruit and vegetables, and its harm

As an indispensable type of food in people's daily diet, fruits and vegetables can provide nutritional health components such as vitamins, minerals, and biological activity with less or less content. The planting of most fruits and vegetables is regional and seasonal. With the development of the national economy, people's demand for fruits and vegetables is increasing, and the demand for fruit and vegetable varieties is no longer limited to local specialties. The supply period of fruits and vegetables has also changed from seasonal supply to annual supply. At present, the area and output of fruit and vegetable planting in my country ranks first in the world.

Fruit and vegetables have the characteristics of crispy, juicy, and juicy. During the storage and transportation process of post -harvesting and sales, diseases are easily invaded and diseased. Gray mold, peach, apricot, Li, and cherry's gray mold and soft corruption, citrus green mold and cyanomy disease, grapes of gray and dark spots, tomato gray mold and dark spots Wait. Pathogen fungus infection will not only cause fruits and vegetables to rot and deteriorate, but more importantly, many pathogenic fungals will produce toxic secondary metabolites -fungal toxins, which contaminate fruits and vegetables and their processing products (fruit juice, fruit wine, etc.), which causes consumer health to cause consumer health Harm, such as extending peniculin invasion of apples to produce penomycin (also known as rodycin), carbon black mold infection with grapes to produce gem mold A (OTA). Therefore, effective and safe measures must be taken to prevent and treat post -piercing diseases.

Traditional prevention and treatment methods of fruit and vegetable disease after mining

The traditional method of preventing and treating the disease after the harvesting of fruits and vegetables includes physics and chemistry. The physical method is mainly to inhibit the activity of pathogenic microorganisms or directly kill pathogenic microorganisms by low temperature storage, heat treatment, air -conditioning storage, and ozone treatment. Low -temperature storage is the most common physical means of fresh -keeping after the harvest of fruits and vegetables, but low -temperature storage has high requirements for equipment and large energy consumption, which indirectly improves the cost of controlling the disease of fruit and vegetables. Thermal treatment can significantly reduce the incidence of the disease after the harvesting of fruits and vegetables, but this method is easy to have adverse effects on the sensory quality of fruits and vegetables, and the energy consumption is higher. Therefore, although these methods are simple and effective, they are restricted in practical applications.

Chemical methods mainly use traditional chemical sterilizers (such as Zhongxuramine, polymorrhine, ilcimazole, methalotobin, etc.) to inhibit or kill pathogenic microorganisms. A significant reduction of fruits and vegetables caused by the infection of the diseased bacteria, and reducing economic losses is a common and effective method for controlling post -harvesting diseases. However, excessive dependence on traditional chemical sterilizers has led to various problems, such as the occurrence of medicinal resistance and the destruction of the ecological environment, especially the residue of the bactericide to the health of the food to be healthy The attention of science and technology workers and relevant national regulatory agencies.

Biological prevention and treatment of fruit and vegetable after mining

The dietary pagoda divides food into cereals, fruits and vegetables, livestock and poultry meat, aquatic products and eggs, milk and dairy products, soybeans, nuts, oil, salt, and sugar. Therefore, the safety of fruit and vegetable food cannot be underestimated. It is necessary to find the safety and effective new methods that can replace chemical sterilizers to prevent and treat post -piercing diseases to ensure the safety of the people's daily consumption of fruits and vegetables.

The biological prevention method uses antagonism to inhibit the growth and reproduction of pathogenic bacteria through the interaction between species, thereby controlling the diseased diseases and inhibiting the production of fungal toxins. Due to the advantages of safety, environmental friendliness, and no drug resistance to pathogenic bacteria, the biological prevention and control law has gradually become a hot spot in controlling the study of the disease after the harvesting of fruits and vegetables, and it is expected to replace the use of chemical sterilizers in the future. So far, scientific researchers have separated hundreds of antagonistic microorganisms, including bacteria, mold and yeast. Among them, the antagonistic yeast bacteria have become commonly used bacteria for controlling the diseases of fruit and vegetables due to strong bacteriostatic ability, high safety, low nutritional requirements, rapid growth and reproduction, and strong tolerance ability to adversity. A antagonistic yeast is not sensitive to most chemical sterilizers, and combined with certain chemicals (such as acidic acid) can also improve its prevention and control effects, and can also be compatible with other control methods. It is currently widely used in grapes, pear fruits, and fruit, pear fruit, and pear fruit, and pear fruits. Apple, citrus, strawberry, tomato, asparagus and other fruit and vegetables have been controlled after mining, and have achieved good results.

The mechanism of using antagonistic yeast to prevent the disease after the harvest of fruits and vegetables

The mechanism of antagonism to control the disease after the use of fruits and vegetables mainly includes three aspects: First, antagonistic yeast and pathogenic bacteria competition nutrition and space, thereby inhibiting the growth of pathogenic bacteria. The antagonistic yeast has strong adaptability and fast reproduction speed. It can occupy spatial sites such as fruit wounds, surfaces or epidermal pores and reproduce faster than pathogenic bacteria, so that the pathogenic bacteria cannot obtain sufficient space and nutrients, thereby inhibiting the occurrence of fruit and vegetable diseases. Second, antagonistic yeast has a heavy parasitic effect on the raw bacteria after the harvesting of fruits and vegetables. Under the electron microscope, the antagonist yeast is adhesive to the pathogenic mycelium, causing the mycelium deformity, and some mycelium structure is destroyed, with obvious depression and collapse. Third, induce improvement of fruit resistance. Compared with the previous two, this is a relatively complicated mechanism. A antagonistic yeast can revitalize the pre -signal transition pathway of the host defense reaction, induce defense reaction genes and protein expression; induce the ability to improve the antioxidant ability of fruits; induce fruit to produce anti -pathogenic substances, and improve the disease resistance of fruits. How to improve the effectiveness of antagonal yeast life

Although the existing research results show that antagonist yeast has a good effect in the prevention and treatment of fruit and vegetables, but compared with chemical fungicides, its prevention and treatment effect is still not ideal. Therefore, it is necessary to continuously explore measures to improve the effectiveness of antagonistic yeast on the prevention and treatment of after -mining of fruits.

The combination of antagonist yeast and other methods such as physical methods, chemical additives, and low -dose chemical sterilizers can improve its biological control effect. Among them, combination with physical methods is more common. For example, combined with ozone can significantly improve the prevention and control of strawberry gray mold (Cryptococcus Laurentii); For example, the combination of tea polyphenol (TP) and H. Uvarum can effectively reduce the occurrence of grapes.

A single antibacterial antibacterial spectrum is narrow and has high dependence on the living environment. In order to improve the effectiveness of antagonist biological prevention and treatment, the research on the control of fruit and vegetable diseases based on composite antagonism has become a research hotspot. Two types of antagonist yeast, RhodosportidiumPaludigenum (RhodosporidiumPaludigenum) combined with the effect of defense for citrus disease, the effect is significantly better than the effects of their own use alone; Bacteria, the combination of Stenotrophomonas Rhizophila can also effectively inhibit the occurrence of melon fruit rot. Endogenesis and endogenous microorganisms may play an important role in fruit and vegetable defense. Therefore, the use of technical means such as microbiology groups to analyze the changes in fruit and vegetable adhesion and endogenous flora, and screen the core microorganisms, which is conducive to building a composite microbial flora to enhance It is efficient in control over fruits and vegetable diseases.

Preparation and industrialization of antagonistic microbial preparations

The ultimate purpose of biological prevention research on fruit and vegetable diseases is to apply antagonistic microorganisms to actual production, so the preparation of antagonistic microbial preparations is one of the key links. During the process of preparation, transportation and preservation, the preparations are easily affected by adverse factors such as high temperature, dryness, and oxidation, resulting in a decrease in the number of live bacteria, which affects its stability, shelf period, and the effectiveness of the lives. This can be solved by the establishment of high -vitality antagonistic microbial preparation technology. Excellent preparation technology can not only improve the survival rate of microorganisms in preparations and enhance its stability, but also reduce production costs. It is very important for accelerating the actual application of antagonistic microorganisms in the prevention and control of fruit and vegetable diseases.

Microbial preparations can be divided into two forms: liquid preparation and solid preparation. Although the cost of the liquid preparation is relatively low, the preservation period is relatively short, and the effectiveness of the prevention is unstable. Mitosacra, galactose, dehydrated milk powder, etc. The preparation of the application of protective agents in a protective agent can significantly improve the activity and preservation period of antagonistic microorganisms. The solid agent has the advantages of long storage period and not easy to be polluted, which is convenient for storage, transportation and quality control. The high number of live bacteria for solid agents preparation of frozen and drying law is currently more commonly used solid preparation preparation methods, but this method has a long drying and high cost. Spray drying has the advantages of dry and fast drying, simple craftsmanship, and continuous production. The required cost is 6--10 times lower than the freezing and drying method. The drying time is also significantly shortened. Maintain high activity for a long time.

At present, some raw preventive agent products have been put into commercial use, such as Aspire (US), Yeild Plus (South Africa), Shemer (Israel), and Candifruit (Spain). my country's research on the prevention and treatment of diseases and vegetables in China has started late. It is still in the stage of promotion and trials, and has not yet been used in actual production. Therefore, the research and application technologies for the prevention and treatment of diseases and vegetables after the harvest of fruits and vegetables still require scientific researchers to continue their efforts to accelerate their industrialization process, help the security of fruits and vegetables in my country, and serve the national health strategy.

(Author: Zhang Hongyin, deputy dean of the School of Food and Biological Engineering, Jiangsu University)

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