Recommendations for Maintaining Postharvest Quality
Trevor V. Suslow and Marita Cantwell
Department of Plant Sciences, University of California, Davis
Maturity & QualityMaturity Indices
Spinach is selected for size and maximal recovery of clean leaves that are mid-maturity to young. Older and yellowing leaves are avoided when making the harvest cut. Generally 3-4 weeks of re-growth are required before a second harvest will yield adequate volume.
Spinach, whether bunched or as leaves, should be uniformly green (generally not yellow-green), fully turgid, fairly clean, and free from serious damage. For bunched spinach, roots should be trimmed short to grade standards and petioles should be predominantly shorter than the leaf blade.
Temperature & Controlled AtmosphereOptimum Temperature
Optimum Relative Humidity
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
Spinach is highly sensitive to exogenous ethylene. Accelerated yellowing will result from low levels of ethylene during distribution and short-term storage. Do not mix loads such as apples, melons and tomatoes with spinach.
Atmospheres of 7-10% O2 and 5-10% CO2 offer moderate benefit to spinach by delaying yellowing. Spinach is tolerant to higher CO2 concentration but no increase in benefits has been observed. Package film for prewashed spinach leaves is selected to maintain 1-3% O2 and 8-10% CO2.
DisordersPhysiological and Physical Disorders
Freezing Injury. Freezing injury will be initiated at -0.3°C (31.5°F). Freezing injury results in watersoaking typically followed by rapid decay by soft-rot bacteria.
Yellowing. Spinach is highly sensitive to exogenous ethylene (See Response to Ethylene).
Harvesting and handling should be done with care to prevent damage to the petioles and leaves. Bunching ties should not be too tight as crushed or split petioles may lead to rapid decay.
Bacterial Soft-Rot (primarily Erwinia and Pseudomonas) is a common problem. Decay is usually associated with damaged leaves and stems.
Package-icing and top-icing loads may be used. Frequent light misting may be done in displays to delay wilting of bunched spinach.
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.
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.