Tips To Help You Manage Postharvest Ripening

Elizabeth MitchamDuring the ripening process, fruit develops desirable eating qualities, including enhanced sweetness, soft and juicy texture, and unique flavor characteristics.

These ripe characteristics make the fruit more desirable to seed dispersers of all types, including animals, birds, and humans. Some fruit must ripen fully on the plant to develop optimum flavor quality. This includes strawberries, sweet cherries, melons, raspberries, oranges, and peaches, to name a few.

Other fruit are harvested mature and ripened after harvest. The term mature means that the fruit have attained a stage at which they can be harvested and ripened to good quality after harvest.

Most of these fruit contain starch reserves at the time of harvest that are converted to sugars after harvest, and therefore the quality of the fruit improves after harvest. This category includes apples, European pears, bananas, kiwifruits, and mangoes.

Getting Fruit Ready To Eat In The Market
Today’s consumer prefers to purchase fruit that are ready to eat. To satisfy this demand, many fruit are ripened partially before retail display. Bananas are the fruit most commonly ripened for retail display, and many years of research and commercial practice has led to the specific protocols that are used by banana ripeners today. Tomatoes (those harvested mature green) and avocados are also frequently ripened after harvest, and pear, kiwifruit, and mango ripening is becoming increasingly common.

There are a number of important factors to consider when ripening fruit to achieve uniform, high-quality ripened products. The most important is the temperature of the product.

Warmer temperatures lead to faster rates of ripening and cooler temperatures slow ripening. However, if the temperature is too high it can impair the flavor quality of the fruit or inhibit full ripening in some cases.

Ripening is best achieved at temperatures between 55°F and 77°F; however, bananas are ripened at lower temperatures (58°F to 65°F). To achieve uniform temperatures within the ripening fruit and therefore ripeness uniformity among the fruit, effective airflow through the packages is required. This is important to bring the fruit to ripening temperatures, manage the temperature during ripening, and, in some cases, cool the fruit after ripening to slow further ripening.

Use of a forced-air system (sometimes called pressure ripening) designed to force room air through the boxes is preferred. Adequate ventilation of the packaging material is critical for airflow. Use of liners and bags will inhibit airflow. When forced-air systems are not available for ripening, boxes can be stagger-stacked on pallets to enhance air exchange for temperature management.

Use Of Ethylene Gas
In addition to uniform temperatures, the ripening of some fruit, such as bananas and green tomatoes, requires the addition of ethylene gas. For other fruit, ripening is faster or more uniform if ethylene gas is added during the ripening process.

Ethylene can be applied using compressed gas cylinders containing diluted ethylene gas or with specialized ethylene generators that release a preset amount of ethylene continually. Ethylene concentrations of 100 parts per million are more than sufficient to stimulate ripening.

Care should be taken to avoid accumulating excessive concentrations of ethylene. When ripening rooms are vented, avoid contamination of produce storage areas, as ethylene has negative impacts on green vegetables and some fruit.

Monitor For Carbon Dioxide
Another gas that must be monitored during fruit ripening is carbon dioxide. If carbon dioxide concentrations are allowed to accumulate higher than 0.5%, this can slow the rate of ripening.

To avoid carbon dioxide accumulation, ripening rooms should, at minimum, be ventilated once every 24 hours. Products with high respiration rates, like bananas and avocados, require about two air exchanges per hour in a typical ripening room filled with fruit. This should be done even while ethylene is being applied, being careful to vent the ethylene to the outside and not the warehouse.

Finally, care should be taken to maintain high relative humidity in the ripening room. At warm ripening temperatures, the rate of water loss from the fruit can be very high if 85% to 95% relative humidity is not maintained.

For more information about ripening of fruit, refer to the Fruit Ripening & Retail Handling Manual produced by the Postharvest Technology Center at Postharvest.UCDavis.edu/bookstore.

Topics: , ,

Leave a Reply

Fruits Stories
Expansion groundbreaking for Southwest Florida Research and Education Center
CitrusSouthwest Florida Research And Education Center Embracing New Expansion
May 20, 2015
A 7,000-square-foot addition to the UF/IFAS facility will house labs and offices for potential new faculty members. Read More
storm clouds
CitrusSouth Florida Rainy Season Could Wind Up On Drier Side
May 20, 2015
National Weather Service anticipating El Niño to play a hand in possible below-normal conditions. Read More
Food SafetyProduce Safety Alliance Offers Course To Become A Certified Trainer
May 20, 2015
The Produce Safety Alliance (PSA) has announced dates for their first two Train-the-Trainer courses this June. The first of the Read More
GrapesMatthew Fidelibus To Be Recognized For Extension Work
May 20, 2015
The American Society of Enology and Viticulture (ASEV) recently announced that Western Fruit Grower™ magazine contributor Matthew W. Fidelibus, of Read More
Apples & PearsGrants Available For Farmworker Education
May 19, 2015
Grants are available for farmworkers and their families interested in attending adult educational programs through the Washington Apple Educational Foundation Read More
Fruits$10 Million Available For California Water Conservation Program
May 19, 2015
Applications for the California Department of Food and Agriculture’s (CDFA) California State Water Efficiency and Enhancement Program (SWEEP) are now Read More
CitrusBad Weather Or Not, Preparation Always On Radar For Florida Farmers [Opinion]
May 19, 2015
You cannot prevent a natural disaster from taking everything you have, but you can lessen the blow if and when it happens. Read More
The Latest
FruitsQ&A With Penn State’s New Young Grower Alliance Coo…
May 22, 2015
Erin Dugan recently joined Penn State University extension as a specialty crop innovations program manager and Young Grower Alliance coordinator. Read More
FruitsHow To Start A Young Grower Association
May 22, 2015
You have recently returned to your family’s business. You have friends and family you can tap for their knowledge and Read More
Expansion groundbreaking for Southwest Florida Research and Education Center
CitrusSouthwest Florida Research And Education Center Embraci…
May 20, 2015
A 7,000-square-foot addition to the UF/IFAS facility will house labs and offices for potential new faculty members. Read More
storm clouds
CitrusSouth Florida Rainy Season Could Wind Up On Drier Side
May 20, 2015
National Weather Service anticipating El Niño to play a hand in possible below-normal conditions. Read More
Food SafetyProduce Safety Alliance Offers Course To Become A Certi…
May 20, 2015
The Produce Safety Alliance (PSA) has announced dates for their first two Train-the-Trainer courses this June. The first of the Read More
Fruits$10 Million Available For California Water Conservation…
May 19, 2015
Applications for the California Department of Food and Agriculture’s (CDFA) California State Water Efficiency and Enhancement Program (SWEEP) are now Read More
CitrusBad Weather Or Not, Preparation Always On Radar For Flo…
May 19, 2015
You cannot prevent a natural disaster from taking everything you have, but you can lessen the blow if and when it happens. Read More
FruitsGreen Fruitworm Numbers High In Pennsylvania
May 19, 2015
In their latest insect report, David Biddinger and Grzegorz Krawczyk, tree fruit entomologists discuss the timing of pest control applications Read More
FruitsUSDA To Invest $21M To Help Growers Cope With Drought
May 18, 2015
USDA’s National Resources Conservation Service (NRCS) will allocate $21 million for growers and ranchers to apply conservation practices in the Read More
BB Hobbs Inc. warehouse in Plant City, FL
CitrusBB Hobbs Bolsters Business In Central Florida
May 18, 2015
Irrigation specialists celebrate opening of new branch warehouse in Plant City. Read More
Disease ControlHow To Control Disease During Rainy Weather
May 18, 2015
The recent warm, wet weather conditions are prime for fungal and bacterial diseases, says Annemiek Schilder of Michigan State University Read More
FertilizerBioWorks Launches New Fertilizer And Biostimulant
May 15, 2015
BioWorks, Inc., launched ON-Gard, a new organic fertilizer and biostimulant. ON-Gard is a 100% plant-derived product with organic nitrogen and Read More
CitrusHouse Votes To Stop “Flawed” Waters Of The United State…
May 15, 2015
The U.S. House of Representatives approved this week bipartisan legislation that requires the withdrawal of the Waters of the United Read More
CitrusPointers On How To Save Money, Increase Sprayer Efficie…
May 15, 2015
Using clean water when calibrating a pesticide sprayer and carrying extra nozzles for quick repair of simple problems in the Read More
Wes Roan of Lipman Produce talks with participants of FFVA's Spring Regulatory Tour.
CitrusFlorida Farming Show & Tell Earns Regulators’…
May 15, 2015
FFVA's annual Spring Regulatory Tour allows those who write regulations controlling water, crop protection chemicals, food safety, and more an opportunity to see production practices firsthand. Read More
CitrusUSDA Announces $11.9M In Assistance For Organic Certifi…
May 14, 2015
Following on the heels of the USDA’s announcement of record growth in the organic sector, the USDA’s Agriculture Marketing Service Read More
CitrusBeekeepers Lost 40% Of Bees In 2014-15
May 14, 2015
Beekeepers across the U.S. lost more than 40% of their honey bee colonies from April 2014 to April 2015, according to the latest results of Read More
FruitsBest Time To Apply Sprays For Insect Control
May 13, 2015
Following petal fall is when apple growers need to be making applications to control plum curculio and European apple sawfly, Read More