Controlling temperature and humidity is crucial to commercial green onion packaging.
Green onions offer a subtle taste after cooking and require special handling when being packaged commercially. The vegetable is extremely fragile and needs to have its moisture content maintained at all times. This is achieved through paraffin-lined boxes and wraps with perforated polyethylene film. When packaged correctly, commercially grown green onions remain fresh enough to sell for up to eight weeks.
Instructions
1. Harvest onions when a minimum of two inches of their white shanks appears out of the ground. Bunch them in groups of six to nine in the field and wrap them in agricultural rubber bands to hold them together.
2. Run the onions through a washer/cooler machine within three hours of harvesting. The water temperature should be 33 to 35 degrees Fahrenheit. Cut each green top to a uniform 12 inches from the top of the bulb. Immediately place up to 12 pounds of the green onions in a box lined with paraffin. The paraffin aids in keeping the moisture on the produce instead of having the box wick it away. Twelve pounds of bunched and iced-down green onions fit in a box that is 20 inches long, 10 inches wide and 6.75 inches high.
3. Ascertain that the loss of moisture is under control. It is imperative in the transport of fresh-cut green onions that the temperature remain a consistent 32 degrees Fahrenheit and the humidity level is kept between 95 percent to 100 percent. Packaging them in perforated polyethylene film or under a layer of crushed ice helps with adding moisture. Green onions can last for up to four weeks under these conditions.
4. Maintain maximum storage by keeping packaged green onions in a controlled environment, like a walk-in cooler, with an atmosphere consisting of 1 percent oxygen with 5 percent carbon dioxide. If the facility is kept at 32 degrees Fahrenheit, the green onions can be stored an additional two to four weeks from the normal four weeks when packed under crushed ice and perforated polyethylene film.
