Strawberry is one of the most fresh fruits susceptible to damage after harvest. 

It is susceptible to picking and handling operations due to its delicate living tissue and the absence of an outer shell to protect the fruit from bruises and wounds, as well as the high rate of respiration of the fruit compared to other fruits and also to increase its moisture content and speed of water loss if stored in the atmosphere Low relative humidity. Hence, strawberries need great care when picking and handling after harvest, quickly cooling and storing at zero degrees Celsius to reduce waste, maintain quality, and market successfully until they reach the consumer.

Strawberry quality characteristics

Since strawberry fruit does not continue to ripen after picking and the sugar content does not increase, it must be ripe when picked. When exporting, the fruits can be picked at the 3/4 coloring stage. The following are the quality characteristics of strawberry fruit.

1-Complete homogeneity The fruits are homogeneous in size inside the package, and the percentage of heterogeneity is not allowed to exceed 5%.

2-The regularity of the color of the fruits.

3-The fruit has reached the stage of full coloration with a bright red color in the case of local marketing and manufacturing, but it must be at the stage of 3/4 coloring when harvested for export.

4-The fruits should have the luster that shows their freshness while retaining the cup and part of the neck, which should be 1 cm long.

5- The fruits should be solid and not overripe.

6- The fruits should contain a high percentage of soluble solids (at least 7%) and have a good flavor.

7-The fruits should be free from mechanical defects, deformation, and traces of disease or insect infection and should not be contaminated with soil.

Ripening and picking the fruits

Strawberry fruits are picked with utmost care, holding the neck between the index finger and thumb and lightly pounding the neck at a length of 1 cm. They are then placed directly in wooden collection boxes lined with sponge chips to prevent bruising and maintain fruit quality. This careful handling is crucial to prevent deterioration and corruption of the fruit. The fruits are then transported to the packing house for further processing. 

The excess neck is cut at 1 cm and wiped with a soft brush to remove the remains of dust and sand. Then, provided that the fruits are homogeneous within one package they are stacked in plastic baskets for a packing capacity of 250 g. These packages are placed inside export cartons.

 Each carton accommodates eight packages, each weighing 2 kg. The cartons are stacked on pallets and entered into the initial cooling chambers to extract the field heat and reduce the fruit's temperature to zero degrees Celsius for 2 to 4 hours.

Direct packing in the field

Recently, an efficient and simple method has been introduced for packing the fruits into export packages directly in the field, reducing the number of times they are traded and ensuring their quality.

 The collection wheel passes (a three-wheeled cart) on which the export packages (the 250-gram package) are placed. The fruits are picked homogeneously, put in the packages directly, and transported. 

These packages are placed inside the cartons and transferred directly to the pre-cooling chambers. 

Fruits that do not conform to export specifications or are overripe are collected in a separate field package and placed at the front of the cart for re-sorting. The damaged ones are excluded and displayed in the local market or manufactured.

Used packaging:

A: The cartons have a capacity of 2 kg.

These cartons must be strong and fixed, and their corners must be reinforced with protrusions that are easy to stack on top of each other. They must have ventilation holes and be clean and brightly colored.

B-cartons of 1 kg.

It is suitable for supermarkets and local marketing in distinguished places, where the fruits are stacked and covered with transparent perforated plastic sheets.

Containers for C-1 kg foam

It is used only in local marketing. It holds 1 kg and is also covered with perforated transparent plastic sheets.

Precooling process 

This process is intended to quickly reduce the temperature of the fruits to zero centigrade in the shortest possible time, reducing the rate of respiration and demolition and extending the life of the fruits. It is carried out on strawberries by forced air cooling. 

The initial cooling process is a crucial step in preserving the quality of strawberries. It helps reduce water loss from the fruit, maintain its freshness, and increase its tolerance for trading operations until it reaches the consumer. In the initial cooling chamber, two pallet stacks are placed in front of the fan and covered inside a plastic tunnel. The fan draws hot air, which is then replaced by cold air, effectively reducing the fruit's temperature. 

The fan draws hot air from being replaced by cold air, which reduces the fruit's temperature.

Storage of fruits after refrigeration

After the rapid cooling process, the pallets are transferred to a particular cooling room at zero degrees Celsius until shipped. 

The fruits may be stored after being injected with carbon dioxide at 12% to 15%. Storing in a modified atmosphere is called a modified atmosphere. Gas enters through a small hole in the bag, sealed by sticking it shut after the injection is finished to prevent gas leakage.

Recent research in this field has proven the possibility of preserving strawberry fruits under modified air conditions for 2 to 4 weeks, maintaining their quality without damage, to extend the marketing period and ease of exporting by land or sea.

Shipping and loading

A-  Air freight

The cooled strawberry fruits are also shipped in refrigerated trucks to the airports. The fruits must remain in refrigerated places during the waiting period at the airport, provided that they are re-cooled after arrival so as not to break the cold chain and preserve them until they reach the consumer.

B. land transport

When calculating the actual cost, the land freight method is cheaper than the air freight method. It is carried out in large trucks chilled to near-zero degrees Celsius before loading.

 The level of insulation, the safety of doors, the efficiency of the refrigeration unit, the method of air agitation, and air paths in each shipment inside the truck must be reassured, and sufficient distances must be left between the pallets. 

And between the front, back, and walls of the truck so that the pallets touching the walls are not affected by the high or low temperature, the back of the car must reach the door of the refrigerated storage room where the fruits are transferred directly from the refrigerated storage rooms to the refrigerated truck to maintain its temperature without fluctuation.

Guiding recommendations for collectors and managers of packing houses for the strawberry crop for export.

First: for managers of packing houses.

1. Place non-smoking signs in the packing house and in the field.

2. Providing bathrooms with hot water and soap without odor, at the rate of one bathroom for every thirty (30) workers.

3. Providing coats (tiles) for collecting, packing, and cleaning workers to ensure cleanliness

4. We exclude workers sick with diarrhea and colds until they are cured to avoid contaminating the fruits with the microbes of these diseases, which would be a source of infection.

Second, some workers collect the crop.

1. Not to smoke in the field or packing house.

2. Avoid eating any foods in the field or in the packing house so as not to leave residues suitable for reproducing microbes that cause fruit damage.

3. Taking into account the necessity of covering hand wounds in particular or any wounds in other places on the body in general with medical plaster

4. Clean your hands with odorless soap and water before entering the farm.