ISO 20981:2020

Asparagus - Specification and test methods

This document specifies requirements and test methods for fresh asparagus shoots of commercial varieties of asparagus grown from Asparagus officinalis L., of the Liliaceae family, offered to consumers after preparation and packaging. This document is applicable to all asparagus except green and violet/green asparagus with a diameter less than 3 mm and white and violet asparagus with a diameter less than 8 mm, packed in uniform bundles or unit packages. This document does not apply to processed asparagus.

Asperges — Spécifications et méthodes d'essai

General Information

• Status: Published
• Publication Date: 10-Aug-2020
• ICS: 67.080.20 - Vegetables and derived products
• Technical Committee: ISO/TC 34/SC 3 - Fruits and vegetables and their derived products
• Drafting Committee: ISO/TC 34/SC 3 - Fruits and vegetables and their derived products
• Current Stage: 9060 - Close of review
• Completion Date: 04-Mar-2031

Overview

ISO 20981:2020 - "Asparagus - Specification and test methods" defines quality, sizing, classification and testing requirements for fresh asparagus shoots (Asparagus officinalis L.) offered to consumers after preparation and packaging. The standard applies to commercially grown fresh asparagus (white, violet, violet/green and green) packed in uniform bundles or unit packages, and excludes very thin spears (green and violet/green < 3 mm; white and violet < 8 mm) and processed asparagus.

Key topics and requirements

• Classification by colour (groups): white, violet, violet/green, green.
• Quality classes: Extra, Class I, Class II - each with progressively relaxed appearance and defect tolerances.
• Size categories: long, short, tip (based on length).
• Minimum diameters and uniformity:
  • White & violet: Extra ≥ 12 mm; Class I ≥ 10 mm; Class II ≥ 8 mm.
  • Violet/green & green: minimum diameters are specified (small-diameter spears below threshold are excluded).
  • Uniformity rules limit diameter variation within a package (e.g., permitted maximum differences for Extra and Class I).
• General product requirements: whole, sound, clean, fresh-looking/smelling, free from insects, wounds and rots; no abnormal moisture, hollows or fractures.
• Appearance rules by class: tip tightness, acceptable rust traces removable by peeling, allowable lignification levels, and colour coverage (e.g., green asparagus green for a specified percentage of length).
• Sampling and tolerances: sampling procedures and tolerances for groups, classes and sizes are defined to support inspection and lot acceptance.
• Test methods (clause 9): procedures for titratable acidity, water‑insoluble solids, mineral impurities content, pH and soluble solids content.
• Packaging, marking, storage and transport: packaging and labelling requirements plus guidance on refrigerated transport and storage to preserve quality.
• Hygiene and residues: clauses address contaminants, hygiene and pesticide residue considerations.

Practical applications and users

ISO 20981:2020 is designed for practical use by:

• Asparagus growers and farm quality managers (grading and harvest specifications)
• Packhouse operators and processors (bundling, trimming, packing criteria)
• Food testing laboratories (applying the standard test methods)
• Produce traders, exporters/importers and retailers (specification, acceptance and quality disputes)
• Cold-chain and logistics providers (storage and refrigerated transport guidance)
• Regulatory and conformity assessment bodies (inspection, sampling and compliance)

Adopting ISO 20981 helps ensure consistent product quality, facilitates fair trade, reduces rejection rates and supports consumer safety and satisfaction.

Related standards

ISO 20981 references and aligns with other standards/guides, including:

• ISO 874 (sampling fresh fruits and vegetables)
• ISO 2859-1 (inspection sampling by attributes)
• ISO 4186 (Asparagus - Guide to storage)
• ISO 6882 (Asparagus - Guide to refrigerated transport)
• CXC 44-1995 (Code of Practice for Packaging and Transport of Fresh Fruit and Vegetables)

Keywords: ISO 20981:2020, asparagus specification, asparagus test methods, fresh asparagus standards, Asparagus officinalis, asparagus grading, asparagus packaging, produce quality.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 20981
First edition
2020-08
Asparagus — Specification and test
methods
Asperges — Spécifications et méthodes d'essai
Reference number
©
ISO 2020
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: [phone]
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Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents  Page
Foreword .iv
Introduction .v
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4  Description . 1
5  Classification and requirements . 1
5.1 General . 1
5.2 Classification . 2
5.2.1 Groups . 2
5.2.2 Classes . 2
5.2.3 Sizes . 2
5.3 Requirements . 2
5.3.1 General requirements . 2
5.3.2 Group requirements. 3
5.3.3 Class requirements . 3
5.3.4 Size requirements . 4
6  Tolerances . 4
6.1 General . 4
6.2 Group tolerances . 4
6.3 Class tolerances . 5
6.3.1 Extra class . 5
6.3.2 Class I . 5
6.3.3 Class II . 5
6.4 Size tolerances . 5
7  Sampling . 5
8  Requirements for contaminants . 5
9  Test methods . 6
9.1 General . 6
9.2 Determination of titratable acidity . 6
9.3 Determination of water-insoluble solids . 6
9.4 Determination of mineral impurities content . 6
9.5 Determination of pH . 6
9.6 Determination of soluble solids content . 6
10  Packaging and marking . 6
10.1 Packaging . 6
10.2 Marking . 6
11  Storage and transportation . 7
12  Hygiene contaminants and pesticides residues . 7
Bibliography . 8
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
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on the ISO list of patent declarations received (see www .iso .org/ patents).
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expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 3,
Fruits, vegetables and their derived products.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved

Introduction
Asparagus is an ancient crop, native to the eastern Mediterranean and Asia Minor, and first cultivated
by the Romans. Popular in sixteenth century France and England, it made its way to America through
the colonists. A member of the lily family, it has great nutritional value. It is low in calories and very low
in sodium. Asparagus is a particularly good source of vitamin B6, calcium, magnesium, zinc, vitamin A,
vitamin C, vitamin E, vitamin K, thiamin, riboflavin, rutin, niacin, folic acid, iron, phosphorus, potassium,
copper, manganese, selenium, chromium, dietary fibre and protein. Asparagus spears can be eaten raw
or cooked.
Asparagus, Asparagus officinalis, is an herbaceous perennial plant in the family Asparagaceae, which is
grown for its young shoots, or spears, which are eaten as a vegetable. The asparagus plant is tall with
scale-like leaves emerging from the underground stem (rhizome) and has stout stems and feathery
foliage. The flowers are bell-shaped and occur alone or in pairs. They are green-white to yellow in
colour. After flowering, a round red berry is formed with one to six black seeds. Asparagus can live
for 20 or more years and can attain a height of between 100 cm to 150 cm. Asparagus originates from
Europe, northern Africa and western Asia.
INTERNATIONAL STANDARD ISO 20981:2020(E)
Asparagus — Specification and test methods
1  Scope
This document specifies requirements and test methods for fresh asparagus shoots of commercial
varieties of asparagus grown from Asparagus officinalis L., of the Liliaceae family, offered to consumers
after preparation and packaging.
This document is applicable to all asparagus except green and violet/green asparagus with a diameter
less than 3 mm and white and violet asparagus with a diameter less than 8 mm, packed in uniform
bundles or unit packages.
This document does not apply to processed asparagus.
2  Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 874, Fresh fruits and vegetables — Sampling
ISO 2859-1, Sampling procedures for inspection by attributes — Part 1: Sampling schem
...