Modern methods for preserving and increasing the shelf life of dried fruits
Introduction
Dried fruits, as one of the most popular and most nutritious foods, have a special place in the Iranian food basket. However, due to their high sensitivity to humidity, heat, and environmental pollution, their proper and principled storage is of great importance. In this article, we will learn about the latest methods for preserving dried fruits and increasing their shelf life; techniques that are used both at home and in industrial environments and prevent mold, deterioration, and reduced quality of dried fruits.
1. Vacuum Packaging
One of the most advanced methods for preserving dried fruits is vacuum packaging. In this method, the air inside the package is removed and due to the removal of oxygen, the possibility of the growth of microorganisms and pests is greatly reduced.
Advantages:
Prevents oxidation of fats
Increases shelf life without using preservatives
Suitable for exporting dried fruits
2. Using protective gases (Modified Atmosphere Packaging – MAP)
In this method, the air inside the package is replaced with gases such as nitrogen or carbon dioxide. This technique prevents the growth of bacteria and fungi and maintains the freshness of dried fruits.
Suitable for:
Pistachios, almonds, walnuts and dried fruits
3. Low temperature storage (home or industrial refrigerator)
Storing dried fruits at low temperatures is one of the simplest and most effective methods for increasing shelf life. Temperatures between 0 and 10 degrees Celsius are very suitable for preventing the growth of pests.
Note: It is better to first place the dried fruits in appropriate packaging so that they do not absorb moisture in the refrigerator or freezer.
4. Using a moisture absorber (silica gel)
Moisture is the most important factor in the deterioration of dried fruits. Placing silica gel or desiccant packets in the packaging of dried fruits prevents the increase in humidity and prevents mold.
5. Using UV or infrared radiation for sterilization
In industrial environments, the use of ultraviolet (UV) or infrared radiation to destroy microbes and fungi on the surface of dried fruits is very practical and safe.
6. Natural coating with a protective layer (Edible Coatings)
In this method, a thin edible layer of natural materials such as gelatin, starch or chitosan is applied to the dried fruits, which prevents contact with oxygen and increases shelf life.
7. Storage in glass or plastic containers with tight lids
In the home environment, using containers with lids that are impermeable to air and moisture is one of the most effective ways to prevent the deterioration of dried fruits.
Note: It is best to store the containers in a cool, dry place away from direct sunlight.
Frequently Asked Questions (FAQ)
1. What is the best temperature for storing dried fruits?
Between 0 and 10 degrees Celsius (refrigerator or cold storage) is the most suitable temperature range to maintain the quality of dried fruits.
2. Can dried fruits be stored in the freezer?
Yes, for a long time (for example, over 6 months), dried fruits can be stored in the freezer with vacuum packaging.
3. Why do some dried fruits get moldy?
The main cause of mold is high humidity, contact with humid air, and storage at inappropriate temperatures.
4. Is it better to use a plastic container or a glass container to store dried fruits at home?
A glass container with a tight lid is a better choice because it does not absorb odors and is less permeable to moisture.
5. Does sunlight affect the shelf life of dried fruits?
Yes, direct sunlight causes oxidation of fats and reduces the quality of dried fruits. Dried fruits should be stored in a dark and cool environment.