Facebook
X (Twitter)
Reddit
Pinterest
Tumblr
Delicious
LinkedIn
StumbleUpon
Vegetables Produce Facts English
Tomato
Recommendations for Maintaining Postharvest Quality
Department of Plant Sciences, University of California, Davis
Maturity & Quality
Maturity Indices Standard Tomatoes. Minimum harvest maturity (Mature Green 2) is defined by internal fruit structure indices. Seeds are fully developed and are not cut upon slicing the fruit. Gel formation is advanced in at least one locule and jellylike material is forming in other locules. Standard tomato quality is primarily based on uniform shape and freedom from growth or handling defects. Size is not a factor of grade quality but may strongly influence commercial quality expectations. Color. Uniform color (orange-red to deep red; light yellow). No green shoulders. Appearance. Smooth and small blossom-end scar and stem-end scar. Absence of growth cracks, catfacing, zippering, sunscald, insect injury, and mechanical injury or bruises. Firmness. Yields to firm hand pressure. Not soft and easily deformed due to an overripe condition. U.S. grades are No. 1, Combination, No. 2, and No. 3. Distinction among grades is based predominantly on external appearances, bruising and firmness. Maturity & Quality Photos
Title: Cherry Tomato Maturity & Ripeness Photo Credit: Adel Kader, UC Davis 
Title: Grape Tomato Maturity & Ripeness Photo Credit: Marita Cantwell, UC Davis 
Title: Tomato Maturity Stages Photo Credit: Marita Cantwell, UC Davis 
Title: USDA Color Chart Photo Credit: Adel Kader, UC Davis
Temperature & Controlled Atmosphere
Mature Green: 12.5-15°C (55-60°F) 18-21°C (65-70°F); 90-95% R.H. for standard ripening 14-16°C (57-61°F) for slow ripening (i.e. in transit).For more details on ripening conditions see Ripening. 90-95% High relative humidity is essential to maximize postharvest quality and prevent water loss (desiccation). Extended periods of higher humidity or condensation may encourage the growth of stem-scar and surface molds.
To calculate heat production, multiply ml CO2/kg·hr by 440 to get BTU/ton/day or by 122 to get kcal/metric ton /day. 1.2-1.5µl/kg·hr at 10°C (50°F) Tomatoes are sensitive to exogenous ethylene and exposure of mature-green fruit to ethylene will initiate ripening. Ripening tomatoes produce ethylene at a moderate rate and co-storage or shipment with sensitive commodities, such as lettuce and cucumbers, should be avoided. Faster ripening results from higher temperatures between 12.5-25°C (55-77°F); 90-95% R.H.; 100 ppm ethylene. Good air circulation must be maintained to ensure temperature uniformity within the ripening room and to prevent the accumulation of CO2. CO2 (above 1%) retards the action of ethylene in stimulating ripening. Controlled atmosphere storage or shipping offer a moderate level of benefit. Low O2 levels (3-5%) delay ripening and the development of surface and stem-scar molds without severely impacting sensory quality for most consumers. Storage times of up to 7 weeks have been reported for tomatoes using a combination of 4% O2, 2% CO2, and 5% CO2. More typically, 3% O2 and 0-3% CO2 are used to maintain acceptable quality for up to 6 weeks prior to ripening. Elevated CO2 above 3-5 % is not tolerated by most cultivars and will cause injury. Low O2 (1%) will cause off-flavors, objectionable odors, and other condition defects, such as internal browning. Temperature & Controlled Atmosphere Photos
Title: High Temperature Effects Photo Credit: Adel Kader, UC Davis 
Title: Temperature Effects on Tomato Photo Credit: Don Edwards, UC Davis 
Title: Tomato Ethephon Effects Photo Credit: Adel Kader, UC Davis 
Title: Tomato Low Oxygen Effects Photo Credit: Adel Kader, UC Davis 
Title: Tomato Respiration vs Ripening Photo Credit: Adel Kader, UC Davis 
Title: Tomato SO2 Damage Photo Credit: Adel Kader, UC Davis
Disorders
Physiological and Physical Disorders Bacterial Soft Rot. Caused by Erwinia spp. can be a serious problem particularly if proper harvest and packinghouse sanitation is not used. [For more information, see our publication “ Fruit Ripening & Ethylene Management ”, available for purchase using our Publication order form .] Disorders Photos
Title: Tomato Alternaria from Chilling Photo Credit: Don Edwards, UC Davis 
Title: Tomato Alternaria Rot (1) Photo Credit: Don Edwards, UC Davis 
Title: Tomato Alternaria Rot (2) Photo Credit: Don Edwards, UC Davis 
Title: Tomato Athracnose Photo Credit: Don Edwards, UC Davis 
Title: Tomato Blossom-end Rot Photo Credit: Marita Cantwell, UC Davis 
Title: Tomato Bruising Scores Photo Credit: Adel Kader, UC Davis 
Title: Tomato Buckeye Rot Photo Credit: Don Edwards, UC Davis 
Title: Tomato Checker-boarding & Mechanical Damage Photo Credit: Adel Kader, UC Davis 
Title: Tomato Chilling Injury Photo Credit: Adel Kader, UC Davis 
Title: Tomato Ghost Spots Photo Credit: Don Edwards, UC Davis 
Title: Tomato Phytophthora (1) Photo Credit: Adel Kader, UC Davis 
Title: Tomato Phytophthora (2) Photo Credit: Adel Kader, UC Davis 
Title: Tomato Radial and Concentric Cracking Photo Credit: Adel Kader, UC Davis 
Title: Tomato Rhizopus Rot Photo Credit: Don Edwards, UC Davis 
Title: Tomato Shoulder Bruise Photo Credit: Adel Kader, UC Davis 
Title: Tomato Solar Yellowing (1) Photo Credit: Adel Kader, UC Davis 
Title: Tomato Solar Yellowing (2) Photo Credit: Adel Kader, UC Davis 
Title: Tomato Sour Rot (1) Photo Credit: Don Edwards, UC Davis 
Title: Tomato Sour Rot (2) Photo Credit: Don Edwards, UC Davis 
Title: Tomato Stemphyllium Rot Photo Credit: Don Edwards, UC Davis 
Title: Tomato Sun Scald Photo Credit: Adel Kader, UC Davis 
Title: Tomato Vibration Damage Photo Credit: Adel Kader, UC Davis 
Title: Tomato Fusarium Rot Photo Credit: Don Edwards, UC Davis
Date
May 1997 |
||||||||||||||||||||
Use of Materials
The UC Postharvest Technology Center grants users permission to download textual pages (including PDF files) from this World Wide Web site for personal use or to reproduce them for educational purposes, but credit lines and copyright notices within the pages must not be removed or modified.
Except for these specified uses, no part of the textual materials available on the UC Postharvest Technology Center Web site may be copied, downloaded, stored in a retrieval system, further transmitted or otherwise reproduced, stored, disseminated, transferred or used, in any form or by any means, except as permitted herein or with the University of California's prior written agreement. Request permission from UC Postharvest Technology Center. Distribution for commercial purposes is prohibited.
The information in this fact sheet represents our best understanding of the current state of knowledge at the time of the latest update, and does not represent an exhaustive review of all research results. Links to any of these UC Postharvest Technology Center pages are permitted, but no endorsement of the linking site or products mentioned in the linking page is intended or implied by such a link.
How to Cite
Author(s) names. Initial publication or update date (located at the top). Title. Link to the specific Produce Fact Sheet webpage (Accessed date)
Example: Cantwell, M. and T. Suslow. 2002. Lettuce, Crisphead: Recommendations for Maintaining Postharvest Quality.
http://ucanr.edu/sites/Postharvest_Technology_Center_/Commodity_Resources/Fact_Sheets/Datastores/Vegetables_English/?uid=19&ds=799 (Accessed January 18, 2014).
