University of California

Vegetables English

Cauliflower

Recommendations for Maintaining Postharvest Quality

cauliflower007
Trevor V. Suslow and Marita Cantwell

Department of Plant Sciences, University of California, Davis

Maturity & Quality

Maturity Indices

Cauliflowers are selected for size and compactness of the head or curd. Mature curds are at least 15 cm (6 inches) in diameter. Loose or protruding floral parts, creating a ‘ricy’ appearance, are a sign of overmaturity. Cauliflower is packaged after being closely trimmed into single layer cartons of 12 to 24 heads, with 12’s most common.

Cauliflower is primarily marketed with closely trimmed leaves and overwrapped with perforated film. Overwraps should provide four to six 1/4-inch holes per head to allow adequate ventilation.

Quality Indices

A firm and compact head of white to cream white curds surrounded by a crown of well-trimmed, turgid green leaves. Additional quality indices are size, freedom from severe yellowing due to sunlight exposure, freedom from handling defects and decay, and an absence of ‘riciness’.

U.S. grade No. 1

Maturity & Quality Photos

cauliflower_green

Title: Green Cauliflower

Photo Credit: Adel Kader, UC Davis  

Temperature & Controlled Atmosphere

Optimum Temperature

0°C (32°F)

Storage of cauliflower is generally not recommended for more than 3 weeks for good visual and sensory quality. Wilting, browning, yellowing of leaves, and decay are likely to increase following storage beyond 3-4 weeks or at higher than recommended storage temperatures.

Optimum Relative Humidity

95-98%

Rates of Respiration

Temperature °C Temperature °F ml CO2/kg·hr
0 32 8-9
5 41 10-11
10 50 16-18
15 59 21-25
20 68 37-42
25 77 43-48

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.

Rates of Ethylene Production


Responses to Ethylene

Cauliflower is highly sensitive to exogenous ethylene. Discoloration of the curd and  accelerated yellowing and detachment of wrapper leaf stalks will result from low levels of ethylene during distribution and short-term storage. Do not mix loads such as apples, melons and tomatoes with cauliflower.

Responses to Controlled Atmosphere (CA)

Controlled or modified atmospheres offer moderate to little benefit to cauliflower. Injury from low O2 (<2%) or elevated CO2 (>5%) may not be visual and will only be evident after cooking. When the curds become grayish, extremely soft, and emit strong off-odor. Higher levels (>10%) of CO2 will induce this injury within 48 hours. Combined low O2 and slightly elevated CO2 levels (3-5%) delay leaf yellowing and the onset of curd browning by a few days.

Temperature & Controlled Atmosphere Photos

cauliflower_discoloration

Title: Discoloration

Photo Credit: Marita Cantwell, UC Davis

cauliflower_ethylene_effects1

Title: Ethylene Effects (1)

Photo Credit: Yilmaz Ilker, Postharvest Consultant, New Jersey 

cauliflower_ethylene_effects2

Title: Ethylene Effects (2)

Photo Credit: Don Edwards, University of California, Davis

Disorders

Physiological and Physical Disorders

Freezing Injury. Freezing injury will be initiated at -0.8°C (30.6°F). Symptoms of  freezing injury include a watersoaked and greyish curd and watersoaked or wilted crown leaves. The curd will become brown and gelatinous in appearance following invasion by soft-rot bacteria.

Harvesting should be done with great care to prevent damage to the highly sensitive turgid curds. Cauliflower should never be handled by the curd portion of the head. Cauliflower should never be allowed to roll or scuff across a harvest -conveyor belt, table, or other work surface. Bruising is very common and leads to rapid browning and decay when attention to careful harvest and handling practices are not followed.

Pathological Disorders

Diseases are an important source of postharvest loss, particularly in combination  with rough handling and poor temperature control. A large list of bacterial and fungal pathogens cause postharvest losses in transit, storage, and to the consumer. Bacterial Soft-Rot (primarily Erwinia and Pseudomonas), Black Spot (Alternaria alternata.), Grey Mold (Botrytis cinerea), and Cladosporium Rot are common disorders.

Special Considerations

For fresh-cut applications, the sensitivity of cauliflower to improper modified atmosphere (See Responses to CA) demands very careful selection of packaging films and proper temperature management.

Disorders Photos

cauliflower_decay_rating_scale

Title: Decay Rating Scale

Photo Credit: Marita Cantwell, UC Davis 

cauliflower_leaf_abrasion_ethylene

Title: Leaf Abscission caused by Ethylene

Photo Credit: Don Edwards, UC Davis  

cauliflower_mechanical_damage1

Title: Mechanical Damage (1)

Photo Credit: Adel Kader, UC Davis  

cauliflower_mechanical_damage2

Title: Mechanical Damage (2)

Photo Credit: Adel Kader, UC Davis  

cauliflower_solar_yellowing

Title: Solar Yellowing

Photo Credit: Adel Kader, UC Davis

Date

February 1998

Use of Materials

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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.

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).

College of Agricultural & Environmental Sciences
Postharvest Technology Center
Department of Plant Sciences

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