In the food industry, refrigeration systems for fruits and vegetables play a fundamental role, since they are responsible for slowing down the growth of bacteria in the products, in order to prevent their loss or deterioration. Both food safety and the cold chain are responsible for working together.

An optimal refrigeration system provides better temperature control, ensuring optimal conservation and organoleptic conditions of the food we purchase. Read on for a broader perspective on the importance of these facilities and how they should be managed.

 

Why are refrigeration systems for fruits and vegetables so important?

In principle, it is necessary that there is an adequate collection, handling, storage, and distribution of fruits and vegetables so that, in this way, the products reach the final consumer in the best conditions. Refrigeration is an essential process to guarantee the freshness of the products and increase their commercial lifetime. Therefore, the production, processing, and marketing companies of these sectors that incorporate adequate commercial and industrial refrigeration systems, obtain as results:

  • The delay of maturation and aging of tissue cells in the products.
  • Control of the attack of microorganisms.
  • Reduction of global quantitative and qualitative losses of products.

Refrigeration systems for fruits and vegetables usually consist of cold rooms provided with a controlled atmosphere. Installations with an ecological profile use CO2, glycol, and ammonia as refrigerants. These chambers have the function of regulating both the temperature and humidity, as well as the circulation and renewal of air.

In particular, this is important for climacteric fruits, such as tomatoes, pears, apples, quinces, and melons. Before collecting them, it is usual to calculate various processes such as the time of collection, transport, storage, and distribution. In this way, the fruit is collected long before its ripening time, a process that will be completed later in the cold stores that maintain ideal conditions, until the moment the product is put on sale.

Variables to control

On the contrary, non-climacteric fruits, mainly citrus (oranges, lemons, and tangerines) and others such as cucumbers and peppers, require another treatment. For the latter, all the aforementioned procedures are calculated, taking into account that the fruit must remain on the plant until it reaches adequate maturation. Therefore, the variables to control and monitor in the refrigeration of fruits and vegetables are temperature, relative humidity, and ventilation.

The right temperature in the cold room

The temperature factor can influence the conditions of the fruits in various ways. Of course, this will depend on whether they are climacteric or non-climacteric. In the first, it will delay its maturation; while in the second, its deterioration will be delayed.

A high temperature in the cold room will cause damage to the fruit tissue and will eliminate its enzymatic activity. If the temperature exceeds 40°C or 60°C respectively, it will generate fermentation with its consequent alcoholic flavors and changes in the texture of the fruits. On the other hand, a low temperature, which reaches a degree of freezing or close to it, will also cause undesirable alterations in both flavor and tissue breakage.

In the case of tropical fruits, especially those sensitive to cold, if they are subjected to temperatures between 5° and 14° for a certain period of time, they will experience blackening and changes in flavor.

For these reasons, temperature control in fruit cooling systems is critical. In fact, this has to be done by means of a field of thermal probes with damping that diverts the interior conditions. In some cases, a control probe could be incorporated into the product, with the aim of monitoring the internal evolution of the fruit over time.

Relative humidity in refrigeration systems for fruits and vegetables

In addition to temperature, we have humidity, which is another key factor in refrigeration systems for fruits and vegetables. Indeed, during the ripening process, the fruits begin to sweat and lose water naturally. So, to avoid their dehydration and the acceleration of senescence, the cold rooms where they are going to be stored must have high relative humidity between 85% and 95%.

Specifically, the ideal humidity percentages are 95% for vegetables and 90% for fruits. However, for each product, this factor will depend on its surface/volume ratio. In the same way, adequate control of these indexes must be carried out, since, otherwise, it can cause the appearance and proliferation of molds.

Relative humidity management is feasible through control systems of the conditions of the refrigerant to be treated, whether it is ammonia, CO2, or glycol, inside the evaporator; or, by wetting the premises with sprayed water or steam.

Ventilation and atmosphere for product conservation

As part of the management of refrigeration systems for fruits, it is essential to control the atmosphere with adequate ventilation. With this measure, it is possible to prevent the respiration of the fruits from developing an atmosphere with an oxygen index of less than 2%. If this were to happen, the fruits that require oxygen to change color during ripening would remain green, thus activating the fermentation processes, which will result in the loss of the fruits.

That is why cold storage rooms must control the appropriate proportions of oxygen and CO2, depending on the product being controlled. Changes in the proportion of these gases will generally be compensated with nitrogen, which does not cause any adverse effect. In turn, it is essential to control the ethylene that emanates from the fruits naturally, as an effect of the ripening itself; something that can be achieved by proper ventilation.

 

Importance of refrigeration systems for fruits and vegetables during distribution

Both fruits and vegetables are part of the category of perishable products. Consequently, its distribution acquires its own characteristics, with the support of a logistics operation that fits in with this type of merchandise. Let us remember that, at certain times, these require ensuring a constant temperature. In other words, the objective is to ensure that the cold chain is not broken.

Based on the above, the transport and storage of fruits and vegetables requires the use of vehicles and spaces with a series of common characteristics in their operation, such as:

  • Limitation of capacity, weight, and dimensions.
  • That optimizes fuel consumption.
  • Structural strength conditions.
  • Adaptability between merchandise and vehicle
  • Relative autonomy and complementarity with other means, be it ship, truck, or train.
  • Definition and compliance with security regulations.

The characteristics mentioned above, common in transport units, condition key aspects at the same time, such as:

  • The volume of the cargo area.
  • Power of the driving machine.
  • Layout and protection of cargo spaces.
  • The comfort and well-being of the crews.
  • Safety of products in transit.

To optimize the quality of the cold chain, there is the CCQI standard or Cool Chain Quality Indicator. It refers to professional temperature control throughout the supply chain. For this purpose, it uses ideal means for managing the transport and storage of Perishable and Temperature Sensitive Products or PTSP. On the one hand, the objective of this regulation is to establish indicators that result from the quantitative evaluation of the quality of the cold chain for individual operations. Additionally, it raises the verification of compliance with the cold chain.

 

At Intersam we also develop refrigeration systems for fruits and vegetables

For 27 years, at Intersam we have developed industrial and commercial air conditioning and refrigeration systems tailored to customer needs. In this sense, we manufacture heat exchangers, condensers, and adiabatic air coolers for all types of processes. Our equipment can be integrated into refrigeration systems for fruits and vegetables, whether in the production, processing, transport or storage phases. As if that were not enough, we have our own software to facilitate its management. Furthermore, we can send our refrigeration and air conditioning solutions to wherever your company is, inside or outside of Spain. Refrigeration is our business! Contact us now!