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How to store fruits and vegetables after harvest?

How to store fruits and vegetables after harvest?

Cập nhật: 04-08-2021 11:12:02 | News | Lượt xem: 63

Most vegetables change very quickly and are very perishable after harvest. This has led to a reduction in yield and quality of harvested vegetables. Currently, there are many methods of preserving fruits and vegetables after harvest. With each different type of fruit and vegetable and depending on the characteristics of the climate and natural conditions in the area, people will choose the methods of preserving vegetables and fruits accordingly. Preserving vegetables

Overview of preserving fruits and vegetables after harvest
According to the Department of Processing, trade in agriculture - forestry - fishery and salt industry. Postharvest losses for fruits and vegetables amount to about 25% for fruits and 30% for vegetables. Fruit and vegetable preservation is an important technology to reduce economic losses for farmers. However, the technology of preserving vegetables and fruits in Vietnam is difficult to meet the needs of vegetable farms. This is one of the reasons leading to fragmented and small production. Therefore, it is difficult to collect and preserve with uniform quality. At the same time, the harvesting techniques of most of our farms are still weak.

Preservation means storing fruits and vegetables so that they are not damaged, deformed or deformed. At the same time, it ensures that the taste, appearance and nutrient composition of vegetables and fruits are preserved for a long time.

The quality of fruits and vegetables depends on many factors such as the type of vegetable and temperature. Composition of air, light, microorganisms, etc.

There are several methods to help preserve fruits and vegetables after harvest.
1. Method to minimize chemical change of vegetables after harvest
Preserving fruits and vegetables after harvesting by physical methods

Refrigeration: This is the most common method of preserving fruits and vegetables after harvest. In this method, people will lower the temperature of the storage environment to nearly 0 degrees Celsius. At this temperature, the water in the material is still in a liquid state, not yet a solid state.


Refrigeration is a popular method of preserving fruits and vegetables after harvest

The temperature in the reserve rooms can be adjusted between -5 and 15 degrees. This method helps to reduce respiration and limit the drainage of vegetables. Frozen foods usually do not keep for a long time, from a few days to a few months. And so this method is often used for some vegetables or used to preserve vegetables that can be consumed quickly such as vegetables in some supermarkets. Preserving vegetables

Chemical preservation

a. Store under controlled atmosphere conditions.

This is a method of preservation under the conditions of the composition of the air. Be actively controlled and adjusted. With this method, people will actively control some components in the air. Possible effects on how quickly fruits and vegetables work after harvest include: CO2, O2.

During the preservation of fruits and vegetables after harvest, with this method. People will reduce the O2 concentration in the air to less than 21% and increase the CO2 content. This will reduce the respiration of vegetables and also reduce physiological activities. Biochemistry is happening in the cells of vegetables and helps them stay fresh longer.

This method can be done in two ways, natural and artificial. With the natural method, people directly regulate the amount of O2 and CO2 in the environment. So that the total amount of CO2 and O2 in the environment is still equal to the total amount in the atmosphere but the ratio will be changed. Meanwhile, with the artificial method, N2 will be added to the preservation environment when the O2 gas has been removed. By exposing air to CH4 or C3H8.Preservation of fruits and vegetables

In general, chemical preservation methods will help preserve fruits and vegetables. For a long time and the quality of vegetables is almost unchanged. However, this method is quite complicated and requires precise techniques during preservation.

b. Use antioxidants


Oxidation will make vegetables easily change flavor and color

The impact of substances in vegetables and the environment will lead to oxidation. And affect the quality and appearance of vegetables. Therefore, to preserve some vegetables, one can use antioxidants. Basic requirements for antioxidants when used in food production include:

Increase the stability of fruit and vegetable quality.
Does not affect the nutritional composition of vegetables
Preserve the correct taste and color of vegetables
Some commonly used antioxidants include: Tocopherol, Ascorbic Acid, BHA, etc.

2. Methods of inhibiting or killing insect microorganisms on fruits and vegetables after harvest

Irradiation or can be understood as sterilization by photochemical agents. According to this method, people will use radioactive rays such as X-rays, gamma rays to preserve food. Some types of irradiation include:

Use infrared to kill fungus
Using ultraviolet rays to kill some harmful microorganisms
This method is very expensive and requires a lot of technique. So almost no farm in Vietnam uses this method.

 Sulfitation – preservation with sulfur anhydride

SO2 gas is a reducing agent with antioxidant effect. There are two methods of preserving fruits and vegetables after harvest, including: sulphation when and wet sulphation

Sulfitation occurs when: SO2 is loaded into the container and sprayed directly into the fruit and vegetable products to be preserved. This method is quite labor intensive and requires many containers so it is quite expensive.
Wet sulfite: SO2 will be charged directly from the steel tank or prepared by burning sulfur in the room. As a result, SO2 gas will

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