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

Farm ManagementUSDA Awards $18 Million To Stimulate Research And Development Innovation
October 22, 2014
The grants will provide resources to help small operations create breakthroughs, says USDA Secretary Tom Vilsack. Read More
CitrusEPA Launches Program To Reduce Pesticide Drift
October 22, 2014
The voluntary star-rating program aims to protect people, wildlife and the environment. Read More
CitrusMcCrometer Introduces New Ag Management Mobile App
October 22, 2014
The app displays data on weather, ET, soil moisture, water flow, and more. Read More
Apples & PearsNew York Apple Growers Partner With Grocer To Introduce SnapDragon Apples
October 22, 2014
First apples of this new variety to hit Wegmans stores as part of a marketing effort. Read More
CitrusAgriculture, Interior Departments Partner To Measure Conservation Impacts On Water Quality
October 22, 2014
Goal is to provide science-based information for watershed wellness. Read More
Stone FruitIntroducing A Gem Of A Peach For Central Florida
October 22, 2014
The newest variety to come from the UF Stone Fruit Breeding Program is another “gem,” UFGem! This peach variety is Read More
CitrusIt’s Time For Young Farming Leaders To Engage [Opinion]
October 21, 2014
Florida Grower editor Frank Giles says there are capable and talented youths in the ag field ready to step up and take the reins. Read More

The Latest

Farm ManagementBill Gates Uploading Lots Of Florida Farmland
October 22, 2014
Recent acquisition for the Microsoft icon involves more than 4,500 acres for nearly $28 million. Read More
FruitsAnnual Santa Maria Strawberry Meeting Approaching
October 22, 2014
The meeting will focus on IPM practices, weed management, updates on fumigation, and more. Read More
Farm ManagementUSDA Awards $18 Million To Stimulate Research And Devel…
October 22, 2014
The grants will provide resources to help small operations create breakthroughs, says USDA Secretary Tom Vilsack. Read More
CitrusEPA Launches Program To Reduce Pesticide Drift
October 22, 2014
The voluntary star-rating program aims to protect people, wildlife and the environment. Read More
CitrusMcCrometer Introduces New Ag Management Mobile App
October 22, 2014
The app displays data on weather, ET, soil moisture, water flow, and more. Read More
CitrusAgriculture, Interior Departments Partner To Measure Co…
October 22, 2014
Goal is to provide science-based information for watershed wellness. Read More
CitrusIt’s Time For Young Farming Leaders To Engage [Op…
October 21, 2014
Florida Grower editor Frank Giles says there are capable and talented youths in the ag field ready to step up and take the reins. Read More
CitrusBayer CropScience Launches New Award To Recognize Produ…
October 21, 2014
Award recognizes innovation that enhances the role of produce in creating better lives. Read More
FruitsCalifornia Department Of Food And Agriculture Awards $3…
October 21, 2014
State Water Efficiency And Enhancement Program highlights projects implement irrigation systems that reduce water and energy use. Read More
FruitsWashington State University Researchers See How Plants …
October 21, 2014
Results could lead to development of crops that recover from sun damage more easily. Read More
CitrusReport: Major Food And Agriculture Employers Can’t Fi…
October 21, 2014
Current shortage of young farming professionals means ample employment opportunity for the next generation. Read More
CitrusGrowers Need To Take The Ball And Run — Now! [Opi…
October 18, 2014
Help yourself, your farm, and fellow colleagues by becoming more involved in your industry. Read More
CitrusScientists Uproot Common “Superweed” Myths
October 15, 2014
A new fact sheet is available that explores the truth behind two fallacies.   Read More
CitrusUF/IFAS Joins In On Specialty Crop Block Grant Bonanza
October 15, 2014
Researchers partnering with FDACS and USDA on 24 separate projects to strengthen the produce market sector. Read More
Citrus2015 Florida Agricultural Hall Of Fame Inductees Announ…
October 14, 2014
Six more to be honored for helping shape and influence the state’s farming industry. Read More
Does Leaf Cover Interfere With Herbicide Efficacy In Grapevines?
FruitsDoes Leaf Cover Interfere With Herbicide Efficacy In Gr…
October 9, 2014
A raking study investigated what effect falling grape leaves has on herbicide efficacy. See the results here from researcher John Roncoroni, farm advisor at the University of California. Read More
Review Of Glyphosate Resistance Of Horseweed
FruitsReview Of Glyphosate Resistance Of Horseweed [sponsor …
October 9, 2014
Horseweed has been in the deeper soils of Sonoma County, California, for a few years but is now a problem. John Roncoroni, farm advisor at the University of California, shares the problems that horseweed is causing for grape production in Sonoma County. Read More
FruitsCornell University To Host Marketing Conference
October 9, 2014
Two-day event focuses on emerging markets, wholesaling, and ethics in agribusiness. Read More