Why vegetables and fruits spoil during storage

After harvesting, the ripening process slows down, but does not stop completely. As a result of different metabolic processes taking place inside vegetables and fruits, ethylene releases, glucose transforms into fructose, the content of pectin, vitamins and other useful substances, as well as juiciness and firmness of the fruit decrease, the wilting process starts and spots begin to appear, which spoils the re-saleable condition of a product. Fungal spores and microorganisms gradually destroy the tissues, triggering the process of spoilage and the development of rot.

The storage life of different products varies, for example, for berries it is about 1-3 weeks, for fresh vegetables – 1-5 months, for apples and pears – up to a year. To extend the shelf life and increase sales of agricultural products, most Polish producers and wholesale companies use Controlled Atmosphere technology.

How Controlled Atmosphere technology works

The principle of creating a controlled atmosphere is to reduce the content of oxygen and increase the content of carbon dioxide in the storage rooms to slow down the ripening process and damage of vegetables and fruits.

FRUTLINE SP. Z O. O. uses hermetic cold storage units for separate storage with the maintenance of a certain temperature and special installations for changing the composition of air, which includes:

  • automatic or manual control system with change of indicators;
  • gas sensors & analyzers;
  • nitrogen generators to reduce O2 content;
  • carbon dioxide and ethylene adsorption devices;
  • humidifiers, etc.

The use of complex and expensive equipment makes it possible to maintain a good marketable condition of fruits and vegetables intended for further sale and consumption all year round.

Controlled Atmosphere Technologies

To create Controlled Atmosphere, several technologies are used, either separately or together. The atmosphere composition is chosen individually for each type of fruit or vegetable.

Common Controlled Atmosphere technology is one of the most common. The O2 content is between 3-4%, CO2 – 3-5% or more. The required oxygen and carbon dioxide concentration is achieved gradually, within 2-3 weeks after loading.

Storage with ultra-low oxygen content between 0.02-1.5% and carbon dioxide between 0.02-2% allows to increase the shelf life of fruits and vegetables by 2-3 times (some varieties of apples can be stored for up to 18 months). It is used in fully airtight chambers, where it is possible to load/unload products fast.

Advanced CA technology - Dynamic Controlled Atmosphere. This system, with the use of special fluorescent sensors, monitors the current condition of the fruit and automatically adjusts the oxygen content in the storage room (0.02-0.6%).

To extend the shelf life of fruits and vegetables, it is possible to apply carbon dioxide shock treatment at the beginning of storage (CO2 concentration is up to 30%) and SmartFresh technology which means adding a special gas mixture to stop ethylene production by fruits.

Low Ethylene Controlled Atmosphere technology (LECA) is often used in combination with a CA technology and removes ethylene produced by fruits and vegetables.

All technologies comply with European food safety standards. CA-stored fruits and vegetables are safe for the health of both people and animals.

Advantages of Controlled Atmosphere

CA storage reduces the intensity of metabolism in the tissues of fruits and vegetables by 2-3 times, inhibits the conversion of glucose to fructose, and preserves the firmness and juiciness of fruits.

According to various studies conducted in the EU and Russia, fruits and vegetables stored in CA for a long time retain more pectin (apples, pears) and vitamins, including carotene and ascorbic acid, than fruits that were stored only at low temperatures. Such fruits are good for a healthy diet.

The shelf life of some varieties of apples (Mutsu, Red Prince, Red Cap, Empire, Red Velox) stored in low-oxygen cold storage units is extended up to 12 months or more.

Fresh strawberries can be stored in CA refrigerators for 3-4 weeks, cherries and black cherries – for up to 30 days. Thus, the sales season of these berries increases by a month and allows wholesalers and stores to gain more profit.

Soft leaves of CA-treated Chinese cabbage retain their elasticity and juiciness for up to 5-6 months.

Recommended storage conditions and periods for certain types of fruits, vegetables and berries

Type

Temperature, °C

Shelf life

CO2 content, %

O2 content, %

Apples

0… +2

8-12 months

1-5

1-3

Pears

-1… +1

9-10 months

0-4

1-3

Plum

-0.5… 0

7-8 weeks

0.05

0.03

Cherry

0

20 days

0.05

0.03

Black cherry

0… +5

30 days

10-15

3-10

Strawberry

0… +5

3-4 weeks

20-30

0-10

Tomatoes

8… 12

1-2 months

80

0-5

Greens, lettuce

0… 5

1-2 weeks

2-5

2-5

CA technology allows to minimize product shrinkage due to spoilage of fruits and vegetables and their natural losses. For example, the wilting of apples is reduced by 20-30%. In low oxygen cold storage rooms, the development of mold and rot slows down, and the costs associated with writing off defective products are reduced, so producers and wholesale companies can offer more favorable purchase prices for high-quality and fresh goods.

Our company has a large storage capacity, equipped with CA cold storage rooms and systems with suitable parameters for each type of product, so we sell fresh fruits and vegetables in large bulk to our customers all year round.