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
IMPAC.org screenshot
Citrus
February 17, 2017
How Precision Agriculture Is Helping Farmers Win Over Consumers
New Florida-based organization is seeking to break down barriers between farmers and shoppers by providing a platform to not only show what is grown, but how it's grown. Read More
Grapes
February 17, 2017
Washington Organization Rebrands Itself
Washington Association of Wine Grape Growers unveils new identity at convention, now known as Washington Winegrowers Association. Read More
Registration area at the 2017 Florida Blueberry Growers Association Spring Meeting
Berries
February 17, 2017
Florida Blueberry Growers Counting on a Comeback
With last season's disaster in the rear view, all eyes are searching for bluer skies. Read More
Agras MG-1 agriculture drone
Equipment
February 17, 2017
Wanted: Tech Innovators for Drone Challenge
Land O'Lakes Prize offers up $150,000 to help make drones more useable for farmers Read More
Fruits
February 17, 2017
Are Drones the Future of Pollination?
Researchers in Japan have turned drones into robot bees as artificial pollinators. Read More
Fruits
February 16, 2017
New App Helps Fruit Growers Calculate Chill Hours
App helps growers calculate chill hours based on locations and models and assess physiological needs of fruit crops. Read More
Brussels Sprout on a fork
Citrus
February 16, 2017
Food Trends Driving Growth Opportunities for Florida Farmers
More niche markets emerging for growers to give consumers what they want and need. Read More
The Latest
Food Safety
February 21, 2017
Food Safety Modernization Act Creeping F…
Massive regulatory overhaul unfolds as the specialty crop industry hopes to ensure common-sense food safety rules and inspection. Read More
Citrus
February 17, 2017
How Precision Agriculture Is Helping Far…
New Florida-based organization is seeking to break down barriers between farmers and shoppers by providing a platform to not only show what is grown, but how it's grown. Read More
Equipment
February 17, 2017
Wanted: Tech Innovators for Drone Challe…
Land O'Lakes Prize offers up $150,000 to help make drones more useable for farmers Read More
Fruits
February 17, 2017
Are Drones the Future of Pollination?
Researchers in Japan have turned drones into robot bees as artificial pollinators. Read More
Fruits
February 16, 2017
New App Helps Fruit Growers Calculate Ch…
App helps growers calculate chill hours based on locations and models and assess physiological needs of fruit crops. Read More
Citrus
February 16, 2017
Food Trends Driving Growth Opportunities…
More niche markets emerging for growers to give consumers what they want and need. Read More
Farm Management
February 14, 2017
Californians Holding Breath as More Stor…
Nearly 200,000 people evacuated below nation’s tallest dam; even growers have had enough for now. Read More
Fruits
February 10, 2017
Immigration Enforcement Warning Issued b…
Association advises members to prepare for Immigration and Customs Enforcement raids in wake of Trump’s executive order. Read More
Fruits
February 6, 2017
Organic Trade Association Rallies Suppor…
Group is encouraging consumers to tell USDA they support an organic research and promotion program. Read More
Citrus
February 5, 2017
New Product Helps Bees Brush Off Mites
A British company developed Bee Gym, distributed by Vita Ltd. Read More
Fruits
February 4, 2017
Pests, Diseases in Organic Growing the t…
Biology, ecology of organic production the focus of two-day event. Read More
Citrus
February 2, 2017
Florida Seeking to Fete More Eco-Innovat…
Nominations open for the Commissioner’s Agricultural-Environmental Award. Read More
Citrus
January 30, 2017
List of Best College Farms Released
Website evaluated farms on sustainability factors, community programming, and courses available at the university or college farm, not just in the classroom. Read More
Fruits
January 30, 2017
Avoid Technology at Your Peril [Opinion]
Like it or not, technology is going to have a dramatic effect on fruit growing over the next few years. Read More
Fruits
January 29, 2017
Hold the Labels, Please [Opinion]
Companies who point out the absence of GMOs can hurt may hurt the produce industry as a whole. Read More
Crop Protection
January 27, 2017
New Foliar-Applied Dual Mode Insecticide…
Cormoran, released by Adama USA, helps protect apples, pears, and other specialty crops, will target egg and larva stage of pests. Read More
Fruits
January 26, 2017
Fruit Breeding Industry Giant Passes Awa…
James N. Moore, who established the fruit breeding program at the University of Arkansas more than a half-century ago, was 85. Read More
Food Safety
January 26, 2017
Crop Advisers Should Help Growers with …
Crop advisers need to step up to the plate and help growers comply with Food Safety Modernization Act – especially onerous ag water mandates. Read More