Produce is a key element of a healthy and varied diet. Fruits and vegetable contain vitamins, fiber and antioxidants are essential to continued health and vitality. To preserve peak flavor as well as the full health benefits of produce, proper harvesting, cooling and storing techniques are necessary. With the use of the right equipment, it is easy to keep fruits and vegetables fresh and flavorful. Semco designs cooling systems to client specifications to provide effective and energy-efficient cooling that is best for the type of produce being cooled and stored.
Importance of Harvesting at the Right Time
The first step to ensuring that your produce will stay fresh and preserve its qualities for as long as possible is to harvest it at the proper time. Harvesting before the proper stage of maturity can result in decreased flavor. On the other hand, if produce is left to mature for too long, it will become fibrous or begin to spoil. Overripe produce can also develop cracks that let in bacteria and accelerate decay.
Using the Proper Harvesting Equipment and Techniques
Using the right equipment and techniques is a significant factor in the quality of the harvested produce. As a general rule, to minimize damage and decay, experts recommend that fruits and vegetables be subject to a minimum of handling, and that harvesting containers should be smooth on the inside so that the produce is not scratched. Bulk bins used for harvesting should either be ventilated or should only be used for a short interval. If your produce will be transported in bulk bins, make sure they are perforated; otherwise, the heat build-up from the produce will accelerate decay. At all times, rough handling of the produce should be avoided as far as possible. In order to reduce cooling needs later on, produced should be harvested during the coolest time of day.
After harvesting, produce is transported to the facility where it is packaged. The specific type of packaging can depend on the size and fragility of a specific fruit or vegetable. Packaging should be optimized for maximum protection from damage and ease of handling. The sturdiness of the packaging can also vary depending on the quantity of produce and the distance and means of future transportation. Materials include cardboard, plastic and wood. Another consideration is the amount of ventilation necessary, particularly for produce with high respiration rates that can generate damaging heat. For this type of produce, some facilities use expanded polystyrene packaging covered with ice.
Utilizing proper cooling methods plays a large role in preserving the high quality of your produce. When cooling procedures are performed correctly, they slow the growth of harmful molds and bacteria, slow water loss that causes wilting, reduce the continuous ripening process that leads to over ripeness, and slows the enzymatic process that results in softening. Cooling your produce allows it to stay fresh and tasty for longer.
The proper cooling method will depend both on the type of produce being harvested and on its volume. Agricultural professionals suggest that harvesters consider the following cooling methods:
- Room cooling
- Forced-air cooling
- Top or liquid icing
- Vacuum cooling
- Evaporative cooling
Packaging Produce with Room Cooling
The simplest method is room cooling, which consists of putting the produce inside a room with refrigeration units cooling the air and insulation to keep the cooled air inside. The advantage of this method is that, depending on the size of the room, it can provide refrigeration to a large volume of produce at one time. Well-designed cooling rooms can also conserve energy. This method is especially effective for produce that has already been pre-cooled. The main disadvantage of this method is that it may not be quick enough for some types of produce. If the produce was not previously cooled and there is still a large amount of field-heat, the produce may not achieve its optimum cooling temperature.
Packaging Produce with Forced-Air Cooling
Forced-air cooling is used to increase the output of a regular cooling room. In addition to the refrigeration units already in the room, forced-air cooling involves installing fans that increase the speed with which the cool air circulates throughout the produce. For maximum energy efficiency, fans may be regulated by a thermostat to automatically turn them off as soon as optimum temperature is reached. This system will also reduce water loss and wilting that can result from over-cooling.
Packaging Produce with Hydrocooling
Hydrocooling is an effective method for produce that can withstand wetting and humidity. To employ this method, chilled water is allowed to flow over the produce. The chief advantage of this method is that it can quickly cool a large volume of produce. On the other hand, this method uses more energy than room cooling and forced-air cooling. It should also not be used on produce that is vulnerable to the microorganisms such as mold and bacteria that can grow in a wet environment.
Packaging Produce with Ice
Ice is also used to cool produce, using either top icing or liquid icing. The top icing method involves placing crushed ice inside the container on top of the produce. For liquid icing, a mix of water and crushed ice is sprayed inside containers through vents. This method is quick way to cool produce without unpacking it. It is especially useful for produce that is packed too densely for forced air to circulate and cool effectively. Once deposited, ice will continue to cool; this property makes this method a good choice for produce with a high respiration rate. Like hydrocooling, this is not an appropriate method for moisture-sensitive produce.
Packaging Produce with Vacuum Cooling
Vacuum cooling is a method that entails placing the produce in a metal cylindrical container and then evacuating the air, which results in the rapid evaporation of water and a lowered temperature. While this method is effective and energy-efficient, the equipment is expensive. As a result, it is used primarily for produce like leafy greens that has a large surface area and is therefore not easily cooled through forced air or hydrocooling.
Packaging Produce with Evaporative Cooling
Evaporative cooling is implemented by misting the produce with water while also directing a stream of dry air at it. This is a good method for produce that needs high humidity and does not need to be very cool. This method will not work to significantly reduce temperatures.
Semco manufactures and installs cooling systems that can be used to optimize the implementation of the above methods. When deciding which system to choose, consider the type of produce that needs to be cooled, as well as its volume and type of packaging.