Stone Fruit Ripening Terminology
• “Mature”
Stone Fruit and Kiwifruit
Ripening
(14-10 pounds)
• “Ready to Transfer” (6-8 pounds)
“Ready to Buy”
Elizabeth Mitcham
Department of Plant Sciences
• Preconditioned
(4-8 pounds)
• “Ready to Eat”
(2-4 pounds)
Many slides courtesy Carlos Crisosto
*Measured at weak position on the fruit
Production
Retail
• Tree Ripe
• Well Mature
(10-14 lbs.)
Consumption
(10-8lbs.)?
>6
FIRMNESS (lbs.)
Warehouse
Yellow Flesh Peach
Consumer Acceptance
4-5
3-4
2-3
<2
(12 lbs.)
0
20
40
60
80
100
CONSUMER ACCEPTANCE (%)
1
Store
Production
Consumption
(2-4 lbs.)
Tree Ripe
Well Mature
(10-14 lbs.)
“Ready to Eat”
Internal Breakdown
Mealiness
Lack of Flavor
Flesh Browning
Uneven Ripening
Warehouse
(12 lbf.)
“Ready to Buy”
Pre-conditioning (ºF)
Mature
Flesh Softening
(6 lbs. P/N)
(5 lbs. plums)
Effect of Temperature on ‘Carnival’ Peach Chilling
Injury After Storage Plus 2 Days at 68ºF
Stone Fruit Transport
• Stone fruit temperature measured upon
arrival at the retail warehouse after 3 days
truck shipment, 1996
36ºF
32ºF
Killing Temperature Range
46ºF
41ºF
Percent of Shipment
Temperature
Nectarine
Peach
Plum
(°F)
(n=103)
(n=102)
(n=87)
<35
14.7
5.9
4.6
35-50
69.9
79.4
71.4
>50
15.7
14.7
24.0
50ºF
Crisosto, Carlos H., F. Gordon Mitchell, and Zhiguo Ju. 1999. Susceptibility to chilling injury of peach, nectarine,
and plum cultivars grown in California. HortScience 34(6):1116-1118.
2
Peach Delayed Cooling
(43% Mealy)
Product Flow Through the
Preconditioning Process
(0% Mealy)
Arrival
0ºC 20 Days
(100% Mealy)
Precooling
•Hydrocooling
•Forced air
•Room Cooling
20ºC 48 Hours + 0ºC 20 Days`
Cold Storage
(0% Mealy)
Holding/Partial
Preconditioning
5ºC 20 Days
Transport
20ºC 48 Hours + 5ºC 20 Days
Warm Packing
Forced Air Cooling
Packaging
•Wax & fungicide
•Segregation
Crisosto, Carlos H., David Garner, Harry L. Andris, and Kevin R. Day. Controlled delayed
cooling extends peach market life. HortTechnology 14:99-104.
Preconditioning
O'Henry Peach Ripening
Basic Requirements
of the Preconditioning Program
14
•Ripening room with forced air capacity
•Ethylene is not needed
•Optimize your fungicide application operation
•Slow fruit softening after preconditioning with low
temperatures
Firmness (Lbs.)
12
10
8
2 lbs./day
6
4
2
0
0
1
2
3
4
5
Days at 68°F (20°C
3
O'Henry Peach Ripening
14
12
12
10
10
Firmness (Lbs.)
Firmness (Lbs.)
O'Henry Peach Ripening
14
8
3 Days
6
Transfer Point
Warehouse / Store
4
Initial Firmness
Warehouse
8
6
4 Days
4
2
“Ready to eat”
Store / Consumer
2
0
0
1
2
3
4
0
5
0
1
2
Days at 68°F (20°C
4
5
KIWIFRUIT RIPENING
KIWIFRUIT RIPENING PROTOCOL
Many slides courtesy Carlos Crisosto
3
Days at 68°F (20°C
Mature
Ripe
(Harvest)
(Consumption)
Not Ready to Eat
Ready to Eat!
•
•
•
•
•
•
•
•
•
•
•
•
•
Hard
LOW
Starchy
Consumer
Sour
Acceptance
Odorless
6.5 - 7.0% SSC
17% DM
Soft, Juicy
No starch
HIGH
Consumer
Sweet
Acceptance
Aromatic
Tasty
13.5 - 14.0% SSC
17% DM
4
Kiwifruit Carbohydrates
Harvest
Mature
Consumption
Ripe
How to Assure Consumer Quality
• Minimum Maturity (6.5% SSC)
• Maximum Maturity (<14 pounds firmness)
• Consumer Quality
(> 16.1% Dry Matter
Starch
Sugars
SSC = 6.2%
SSC = 14%
Buyer-Consumer Quality-DM
• Minimum 16.1% DM as a consumer quality index
• For kiwifruit with TA ≤ 1.2%, a DM index of 15.1% is the
minimum quality index required for consumer
acceptance
KIWIFRUIT RIPENING PROTOCOLS
(‘Hayward’)
• IMMEDIATELY AFTER HARVEST
(Shipper/Handlers)
• AFTER COLD STORAGE
(Shipper/Retail)
• HOME (Consumers)
5
IMMEDIATELY AFTER HARVEST
Ripening at the Shipping Point
COLD Ethylene Conditioning Treatment
• Ethylene pre-conditioning treatment is required
only on freshly harvested kiwifruit or those that
have been in cold storage <5 weeks.
Ripening at the Shipping Point
Cold Ethylene Conditioning Treatment
• Ethylene applied at 100ppm for 6-12 hours at 0 to 7°C
(32 to 45°F)
– induces uniform kiwifruit softening and starch conversion into
sugars
– Continuous ethylene application with Catalytic Generator
reduces exposure to 6 hours
• No ethylene is required for kiwifruit that has
been stored for longer than 5 weeks
POST-TREATMENT
HANDLING
Use of Liners
During Kiwifruit
Ripening
• Maintain treated kiwifruit below 36oF.
• Ship and consume fast.
•
•
•
Ethylene can
penetrate liners
Liners avoid or reduce
fruit shriveling
80-90% RH
• Cold store away from kiwifruit intended for
long-term storage.
6
Postharvest Life Potential of
Cold Conditioned Kiwifruit
• Cold kiwifruit treated with ethylene at near
0°C (32°F) and maintained at that
temperature may be held 3-6 weeks longer
• These cold treated kiwifruit will reach a
firmness of about 3 pounds in 2 to 3 days
after being transferred to 20°C (68°F).
Relationship between temperature and flesh
softening of firm kiwifruit (6-9 lbs.)
stored more than 5 weeks
12
45°F
55°F
10
Firmness (lb)
68°F
8
6
Ripening by the Receiver
• Kiwifruit stored <5 weeks and/or >8-10 lbs. upon
receipt
– Treat with ethylene to enhance ripening
• Fruit stored >5 weeks and >5 lbs. and <8-10 lbs.
– ripen by temperature management
Determining Stage of Ripening
• Fruit firmness is the best measurement of ripeness
• Firmness of a mature fruit varies from 16-12 pounds
• Minimum shipping/packing firmness of 5 lbs.
recommended, depending on package type, to avoid
physical damage during transportation and handling
• During ripening, fruit soften and firmness decreases,
reaching values of 2-4 pounds
4
• When fruit reaches 2-4 pounds it is considered ripe or
“ready to eat.” This is the level that kiwifruit will achieve
its best eating characteristics
2
0
0
2
4
6
8
10
Days
7
Questions?
8