University of California

Vegetables English

Brussels Sprouts

Recommendations for Maintaining Postharvest Quality

brussels sprouts016
Marita Cantwell and Trevor Suslow

Department of Plant Sciences, University of California, Davis

Maturity & Quality

Maturity Indices

Brussels sprouts are the compact vegetative buds that develop along the stem of the Brussels sprouts plant. They should be harvested when the buds are firm, but not overmature which is indicated by splitting of the outer leaves.

Quality Indices

Good quality Brussels sprouts should be bright green, without yellowing or discoloration, and have a firm texture. The butt end may be slightly discolored, but should not be dark. Brussels sprouts should be sweet and mild in flavor when cooked. Bitterness varies among cultivars and is associated with high concentrations of specific glucosinolates (sinigrin and progoitrin). Bitterness can also be induced by storage conditions (see Responses to Controlled Atmospheres).

Temperature & Controlled Atmosphere

Optimum Temperature and Relative Humidity

Brussels sprouts are moderately perishable and can be stored 3-5 weeks at temperatures near the optimum of 0°C (32°F). Shelf life at 5°C (41°F) is 10-18 days and at 10°C (50°F) is less than 7 days. Brussels sprouts are often hydrocooled, but can be air cooled as well. Although they have considerable wax on their leaves, they become flaccid due to water loss if high relative humidity is not maintained. 

Freezing Injury. Brussels sprouts freeze at about -0.6°C (30.9°F). Slight freeze damage on the outer leaves of buds may result in small dark and translucent areas. Severe freeze damage results in the entire bud becoming dark and translucent, and very soft after thawing.

Optimum Relative Humidity

>95%

Rates of Respiration

Brussels sprouts have relatively high respiration rates. The highest rate at each temperature corresponds to measurements within 1-2 days of harvest.

Temperature 0°C (32°F) 5°C (41°F) 10°C (50°F) 15°C (59°F) 20°C (68°F)
ml CO2/kg·hr 5-15 11-24 20-40 30-50 45-75

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

Ethylene production rates are slightly higher than those of other green and leafy vegetables, but can still be classified as low:

Responses to Ethylene

Brussels sprouts are sensitive to exposure to ethylene. Leaf yellowing and leaf abscission are the most common symptoms of ethylene injury. 

Responses to Controlled Atmosphere (CA)

Brussels sprouts can be benefited by 1-4% O2 with 5-10% CO2 atmospheres at 2.5-5°C (32-41°F). The main benefits are reduced yellowing and decay, reduced butt discoloration and inhibition of ethylene production. No benefits of CA are observed if the Brussels sprouts are kept at their optimum storage temperature 0°C (32°F). Low oxygen storage (<1%) can cause extreme bitterness and may also cause internal discoloration. Atmospheres of 10-12% CO2 can result in off-flavors and off-odors.

Disorders

Physiological and Physical Disorders

Freezing Injury. Brussels sprouts freeze at about -0.6°C (30.9°F). Slight freeze damage on the outer leaves of buds may result in small dark and translucent areas. Severe freeze damage results in the entire bud becoming dark and translucent, and very soft after thawing.

Puffiness. Or lack of firmness is undesirable in the buds and may vary among cultivars and growing conditions.

Internal browning. Can occur under very wet production conditions and is associated with condensation on the developing leaves. 

Physical Injury. Rough handling at harvest can bruise the buds and increase decay. 

Pathological Disorders

Brussels sprouts are not very prone to postharvest decay, but may be affected by the same organisms that infect other Brassica vegetables. Bacterial decay due to various soft-rot causing organisms (Erwinia, Pseudomonas) may infect sprouts, but bacterial decay is usually associated with physical injury. Less common are fungal pathogens, which can occur under rainy and cool growing conditions.

Disorders Photos

InternalBrowning

Title: Internal Browning

Photo Credit: Don Edwards, UC Davis

Date

February 2001

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.

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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).

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