Methods for Cooling Papayas After Harvest

Due to the increase in demand for the tropical papaya fruit, the number of farmers growing this delectable food has increased. With that demand comes the need for knowledge of the best methods for cooling papayas after harvest along with the safest ways to store the fruit. For those working in the field of papaya production, here is an informative guide to harvesting, cooling, and preparing papaya for hungry consumers around the globe.

A Brief History of the Papaya

Originating in Mexico and Central America, the exotic, tropical, and delicious papaya is a fruit with an incredible history. Before it was grown in the United States, India, and parts of Africa, the native peoples of Latin America cultivated this large, orangey-pink fruit. Used for soups or stews and eaten raw, the fruit was a staple in the diets of the native tribes. The seeds were even used to treat parasites, ringworm, and general stomach aches. The flesh of the fruit was eaten to decrease constipation and revitalize health. Today people all around the world still enjoy this fruit and its amazing flavors and benefits to the human body. It’s no wonder that Christopher Columbus dubbed it the “Fruit of Angels.”

When to Pick Papayas

Before a papaya can be cooled and readied for shipment, it has to be picked at the correct time. When papayas are just beginning to grow, their skin is green and hard. As the fruit matures, the skin will transform into a golden yellow color. When about 20% to 33% of the skin has turned yellow, the fruit will be ready to pick. However, if a papaya is left on the tree even after part of the skin has turned yellow, the fruit will become sweeter due to the increase of sugars. This means a more pleasant and rich flavor for the consumer.

Decrease Respiration Rates

One of the most important aspects of post-harvest cooling and storage is keeping the rates of respiration in the papayas quite low. If the respiration rate increases, the fruit will lose flavor, density, and nutritional value. Therefore, papayas must be stored at cool temperatures immediately after harvesting them from the plant. Here are some guidelines for controlled atmosphere temperatures based on the ripeness of the papayas.

  • Ripe, more than ½ of the fruit is yellow: 45° F; 7° C
  • Partially ripe, ½ to ¼ of the fruit is yellow: 50° F; 10° C
  • Immature green, less than ¼ yellow: 55° F; 13° C

A higher controlled atmosphere temperature will result in higher respiration rates. Thus, anyone harvesting papayas should maintain a constant cooling temperature for post-harvest storage to increase the lifespan of the fruits. It is also imperative to store the papayas under 90% to 95% humidity rates. This highly moisturized air will be similar to the tropical atmosphere the papaya was grown in and will result in more uniform ripening as well.

Be Aware of Ethylene

Another factor to keep in mind when cooling papayas is the fruit’s production of ethylene. A compound produced by certain fruits as they ripen, ethylene can be harmful to a farmer’s crop. When a fruit, like a papaya, is stored next to other fruits in tight quarters, the ethylene produced by the papaya will begin to ripen the other fruit as well. Unfortunately, this can lead to the growth of disease and rot in the produce. Therefore, to help ensure the best taste and quality, most fruits, including papayas, and vegetables, should be stored separately and away from other produce and meat products.

Shelf Life

After papayas have been picked and cooled, their shelf life ranges from 3 days to a month. This wide range depends upon the ripeness of the fruit. Papayas that are fully ripe and sent to market will have a stable shelf life of 2 to 3 days. However, fruit that is mostly green can be stored in a refrigerator between 39 °F and 40°F for close to 30 days. Papayas that are about halfway ripe will have a shelf life of 5 to 7 days.

Building a Cooling System

Farmers looking to increase their crop loads and provide the healthiest, tastiest, and highest quality produce should invest in a cooling system for their harvesting productions. SEMCO/SEMCOLD LLC provides industrial cooling systems based on customer specifications for the types of produce clients need to prepare their produce for shipping and selling. While the best methods for cooling papaya after harvest are listed above, a farmer cannot be successful without the proper equipment. Therefore, investing in an industrial cooling system will be a great benefit to the farmer and the customer wanting fresh, nutritious and delicious produce.

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