ISO/FDIS 21921
(Main)Oxidized starch in food applications — Specifications and test methods
Oxidized starch in food applications — Specifications and test methods
This international standard specifies the physical, chemical and microbiological requirements for and test methods of oxidized starch.
Amidon oxydé dans les applications alimentaires — Spécifications et méthodes d'essai
General Information
Buy Standard
Standards Content (Sample)
FINAL DRAFT
International
Standard
ISO/TC 93
Oxidized starch in food
Secretariat: BSJ
applications — Specifications and
Voting begins on:
test methods
2025-06-17
Voting terminates on:
2025-08-12
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
FINAL DRAFT
International
Standard
ISO/TC 93
Oxidized starch in food
Secretariat: BSJ
applications — Specifications and
Voting begins on:
test methods
Voting terminates on:
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland Reference number
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 1
4.1 Physical indexes.1
4.2 Chemical indexes .2
4.3 Contaminant limits .2
4.4 Microbiological limit.3
5 Test methods . 3
5.1 Reagents .3
5.2 Iodine stain .3
5.3 pH .3
5.4 Copper reduction .3
5.5 Carboxyl group .3
5.5.1 Qualitative test for oxidized starch .3
5.5.2 Quantitative test for oxidized starch .4
6 Marking, packaging, transport and storage requirements . 5
6.1 Marking .5
6.2 Packaging .5
6.3 Transport .5
6.4 Storage .5
Bibliography . 6
iii
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 committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. 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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and 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 93, Starch, derived and by 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
Introduction
Starch consists mainly of amylose and amylopectin. Amylose is a linear molecule of α-D-glucopyranosyl
units linked by (1-4)-α-linkages. Amylopectin is a highly branched polymer of α-D-glucopyranosyl units
linked by (1-4)-α-linkages and by (1-6)-α- linkages that constitute the branch points. In general, each glucose
unit possesses a maximum of three hydroxyls that can undergo chemical substitution. A fourth substitution
is also possible if that at carbon four (4) is not involved in a glycosidic bond. Several methods of starch
modification exist and are applied to improve starch functionality. The most common sources of native
starch used in these modifications are various roots, tubers, cereals and legumes.
Oxidation, a form of chemical modification, involves the deliberate introduction of carboxyl groups in
the starch molecule. A common method of starch oxidation is the treatment of native starch with sodium
hypochlorite. Once oxidized, starch can additionally be subjected to acid, alkali, enzyme, or bleaching
treatment (FAO/WHO 2016).
Starch is a widely applied industrial additive, e.g., in the food industry, where it is utilised as emulsifiers,
stabilizers, binders and or thickeners.
v
FINAL DRAFT International Standard ISO/FDIS 21921:2025(en)
Oxidized starch in food applications — Specifications and
test methods
1 Scope
This document specifies the physical, chemical and microbiological requirements and test methods for
oxidized starch in food applications.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
starch
carbohydrate polymer consisting of a large number of glucose units linked together primarily by alpha
1-4 glycosidic bonds
Note 1 to entry: The starch polymers come in two forms: linear (amylose) and branched through alpha 1-6 glycosidic
bonds (amylopectin), with each glucose unit possessing a maximum of three hydroxyls that can undergo chemical
substitution.
3.2
native starch
starch extracted from plant cells in its natural state as granules, which has not been subjected to any form of
modification resulting in physical and or chemical change
3.3
oxidized starch
modified starch prepared from the treatment of starch with an oxidizing agent can be inclusive but not
limited to hypochlorite
Note 1 to entry: The de-polymerization process lowers the viscosity of the starch with the introduction of the
functional groups, thereby retarding re-crystallisation.
4 Requirements
4.1 Physical indexes
Physical indexes shall comply with the requirements given in Table 1.
Table 1 — Physical indexes of oxidized starch
Item Description
Appearance Powder, granule, coarse particles
Colour White or nearly white
Granular structure typical polarization cross of the
Microscopy
starch source
Solubility Sparingly soluble in cold water, ether, alcohol
Odour No off odour
Taste Foreign taste
Foreign material Free of any foreign matter
4.2 Chemical indexes
Chemical indexes shall comply with the requirements given in Table 2.
Table 2 — Chemical indexes of oxidized starch
Item Limit/Description
pH 4,5 – 7,5
Potato starch
Cereal starch Other starches
Moisture content (g/kg) Min Max
10 21 14 18
Sulfur dioxide, (mg/ kg) ≤ 50 d.b for modified cereal starches; ≤ 10 d.b for other modified starches
Total Ash g/kg for dry matter NMT 0,5
Crude Fat ,g/kg 0,2
Protein, g/kg for dry base 0,5
Present or absence
Proportion g/kg for dry base of
carboxyl groups *
NMT (≤ 1,3 g/kg d.b)
Key
TS test solution
d.b dry base
NMT not more than
NOTE Proportion dry base of carboxyl groups in the final product is not more than 1,1 and only applies to food processing.
NOTE 2 Information in this table is from ISO 3947 and ISO 3188.
4.3 Contaminant limits
Contaminant limit shall comply with the requirements shall comply with given in Table 3.
Table 3 — Contaminant limit of oxidized starch
Item Limit (NMT)
Arsenic (As), mg/kg 1
Lead (Pb), mg/kg 1
Mercury (Hg), mg/kg 0,1
Cadmium (Cd), mg/kg 0,1
Key
NMT not more than
NOTE Contaminant limits of oxidized starch are from ISO 11212-1, ISO 11212-2, ISO
11212-3 and ISO 11212-4.
...
202X-XX-XX
ISO/DISFDIS 21921 :2025(en)
ISO /TC 93
Secretariat: BSJ
Date: 2025-06-02
Oxidized starch in food applications — Specifications and test
methods
FDIS stage
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'sISO’s member body in the country of the requester.
ISO copyright office
Case postale 56 ∙ CP 401 • Ch. de Blandonnet 8
CH-12111214 Vernier, Geneva 20
Tel.Phone: + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail: copyright@iso.org
Web www.iso.org
Website: www.iso.org
Published in Switzerland.
ii
ISO/DISFDIS 21921:2025(en)
Contents Page
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements. 2
5 Test methods . 4
6 Marking, packaging, transport and storage requirements . 6
Bibliography . 7
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 2
4.1 Physical indexes . 2
4.2 Chemical indexes . 2
4.3 Contaminant limits . 3
4.4 Microbiological limit . 3
5 Test methods. 3
5.1 Reagents. 3
5.2 Iodine stain . 4
5.3 pH 4
5.4 Copper Reduction . 4
5.5 Carboxyl Content . 4
5.5.1 Qualitative test for oxidized starch . 4
5.5.2 Quantitative test for oxidized starch . 4
6 Marking, packaging, transport, and storage requirements . 5
6.1 Marking . 5
6.2 Packaging . 6
6.3 Transport. 6
6.4 Storage 6
Bibliography . 7
iiiiii
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 committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. 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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents.www.iso.org/patents. ISO shall not be held responsible for identifying any or all such
patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and 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.htmlwww.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 93, Starch, derived and by 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.
Field Code Changed
iv
ISO/DISFDIS 21921:2025(en)
Introduction
Starch consists mainly of amylose and amylopectin. Amylose is a linear molecule of α-D-glucopyranosyl units
linked by (1-4)-α-linkages. Amylopectin is a highly branched polymer of α-D-glucopyranosyl units linked by
(1-4)-α-linkages and by (1-6)-α- linkages that constitute the branch points. In general, each glucose unit
possesses a maximum of three hydroxyls that can undergo chemical substitution. A fourth substitution is also
possible if that at carbon four (4) is not involved in a glycosidic bond. Several methods of starch modification
exist and are applied to improve starch functionality. The most common sources of native starch used in these
modifications are various roots, tubers, cereals and legumes.
Oxidation, a form of chemical modification, involves the deliberate introduction of carboxyl groups in the
starch molecule. A common method of starch oxidation is the treatment of native starch with sodium
hypochlorite. Once oxidized, starch can additionally be subjected to acid, alkali, enzyme, or bleaching
treatment (FAO/WHO 2016).
AsStarch is a widely applied industrial additive, e.g., in the food industry, where it is utilised as emulsifiers,
stabilizers, binders and or thickeners.
vv
Oxidized starch in food applications — Specifications and test
methodmethods
1 Scope
This document specifies the physical, chemical and microbiological requirements and test methods for
oxidized starch in food applications.
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 3188, Starches and derived products — Determination of nitrogen content by the Kjeldahl method —
Titrimetric method
ISO 3947, Starches, native or modified — Determination of total fat content
ISO 5809, Starches and derived products — Determination of sulphated ash
ISO 5379, Starches and derived products — Determination of sulfur dioxide content — Acidimetric method and
nephelometric method
ISO 1666, Starches and derived products – Determination of moisture content – Oven drying method
ISO 11212-1, Starch and derived products — Heavy metals content — Part 1: Determination of arsenic content
by atomic absorption spectrometry
ISO 11212-2, Starch and derived products — Heavy metals content — Part 2: Determination of mercury content
by atomic absorption spectrometry
ISO 11212-3, Starch and derived products — Heavy metals content — Part 3: Determination of lead content by
atomic absorption spectrometry with electrothermal atomization
ISO 4831, Microbiology of food and animal feeding stuffs — Horizontal method for the detection and
enumeration of coliforms — Most probable number technique
ISO 4832, Microbiology of food and animal feeding stuffs — Horizontal method for the enumeration of coliforms
— Colony-count technique
ISO 21527-2, Microbiology of food and animal feeding stuffs — Horizontal method for the enumeration of yeasts
and moulds — Part 2: Colony count technique in products with water activity less than or equal to 0,95
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obphttps://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/https://www.electropedia.org/
3.1 3.1
starch
carbohydrate polymer consisting of a large number of glucose units linked together primarily by alpha 1-
4 glycosidic bonds
Note 1 to entry: The starch polymers come in two forms: linear (amylose) and branched through alpha 1-6 glycosidic
bonds (amylopectin), with each glucose unit possessing a maximum of three hydroxyls that can undergo chemical
substitution.
3.2 3.2
native starch
starch extracted from plant cells in its natural state as granules, which has not been subjected to any form of
modification resulting in physical and or chemical change
3.3 3.3
oxidized starch
modified starch prepared from the treatment of starch with an oxidizing agent can be inclusive but not limited
to hypochlorite
Note 1 to entry: The de-polymerization process lowers the viscosity of the starch with the introduction of the functional
groups, thereby retarding re-crystallisation.
4 Requirements
4.1 Physical indexes
Physical indexes shall comply with the requirements given in Table 1.Table 1.
Table 1 — Physical indexes of oxidized starch
Item Description
Appearance Powder, granule, coarse particles
Colour White or nearly white
Granular structure typical polarization cross of the
Microscopy
starch source
Solubility Sparingly soluble in cold water, ether, alcohol
Odour No off odour
Taste Foreign taste
Foreign material Free of any foreign matter
4.2 Chemical indexes
Chemical indexes shall comply with the requirements given in Table 2.Table 2.
Table 2 — Chemical indexes of oxidized starch
Item Limit/Description
pH 4,5 – 7,5
Moisture content (g/kg) Potato starch Cereal starch Other starches
Item Limit/Description
Min Max
10 21 14 18
Sulfur dioxide, (mg/ kg) ≤ 50 d.b for modified cereal starches; ≤ 10 d.b for other modified starches
Total Ash g/kg for dry matter NMT 0,5
Crude Fat ,g/kg 0,2
Protein, g/kg for dry base 0,5
Present or absence
Proportion g/kg for dry base of
carboxyl groups *
NMT (≤ 1,3 g/kg d.b)
TS – test solution; d.
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.