After the harvest of a beautiful crop of produce, growers must then consider how to quickly and completely cool their harvest to keep it in peak condition for transport and sale. At Semco, we manufacture and install industrial grade cooling systems that are custom designed to meet each client’s specific needs and facilities. Cooling produce immediately after harvest will help maintain freshness and quality in produce. If not properly cooled and stored, fresh produce is subject to rot or degradation of firmness and overall quality. Prompt and proper cooling slows down ripening, softening and color changes and keeps off spoilage due to various bacteria, yeasts or fungi.
Various Cooling Methods
There are many methods used to cool produce. Room cooling involves storing produce in insulated rooms equipped with refrigeration units. Forced-air cooling is a system where fans are employed in conjunction with room cooling to pull the cool air through packaged produce containers. Hydrocooling means dumping produce into cold water or placing cold running water over the produce to quickly clean and remove heat from the produce.
The Benefits of Icing
Icing is another cooling technique. Ice cooling involves adding crushed ice to the container on top of the produce either by hand or through machine application. This article will focus on ice cooling.
Ice can be applied to produce packaging in a number of ways. Crushed ice can be added to each package manually, but this is a labor intensive, slow process that is not functional for high-volume facilities. Liquid icing injects water and ice into produce packages through prepared vents or handles without removing the packages from storage pallets or having to open the tops of the packages. Specific machinery can be customized to meet a facility’s specifications, can quickly inject the slurry of ice and water into each package as the containers of produce travel along a conveyor belt.
Liquid icing can also be applied through handle openings in the sides of boxes with the use of a hose. The water does most of the cooling with the ice helping to keep the temperature of the produce low. One benefit of such a method is that the packages can remain closed so that workers utilizing the equipment can quickly ice large pallets of boxed produce. Because liquid icing wets the produce, it must not be allowed to warm up again or the produce will be susceptible to postharvest diseases. Top icing, a method of applying a two to four inch layer of crushed ice to the top of packaged, precooled produce pallets can help to maintain additional cooling for the top few layers of produce packed into a truck. Top icing doesn’t effectively cool all of the pallets, but it can maintain a low temperature.
Produce That Does Well With Ice Cooling
Ice cooling is particularly effective for produce with high respiration such as sweet corn or broccoli. Produce that is well-suited for icing include the following fruits and vegetables:
- Green Onions
- Leafy Greens
- Sweet Corn
Not all produce types are good candidates for ice cooling, however. Products that are damaged by ice, such as berries, tomatoes, squash, green beans, cucumbers, onions, Romaine lettuce and herbs should not be cooled using an icing method. Icing such delicate items can spoil them completely and make them unsuited for sale and consumption. At Semco, we can help you understand your produce-cooling options and build a system custom designed for your facility.